MK3.5S

<p><strong>MK4 to MK4S upgrade <br /></strong></p>
<p>The current lead time is <strong>1-2 weeks </strong>for both xLCD versions.</p>
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<td style="width: 29.0798%; height: 28.375px; border-style: dotted; border-width: 1px; text-align: left;">Order week</td>
<td style="width: 29.2017%; height: 28.375px; border-style: dotted; border-width: 1px; text-align: left;">Order date</td>
<td style="width: 41.7185%; height: 28.375px; border-style: dotted; border-width: 1px; text-align: left;">Shipping estimate</td>
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<td style="width: 29.0798%; border-style: dotted; border-width: 1px; text-align: left; height: 33.25px;">Week 33</td>
<td style="width: 29.2017%; border-style: dotted; border-width: 1px; text-align: left; height: 33.25px;">starts August 12, 2024</td>
<td style="width: 41.7185%; height: 33.25px; border-style: dotted; border-width: 1px; text-align: left;" rowspan="4">Already shipped</td>
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<td style="width: 29.0798%; border-style: dotted; border-width: 1px; text-align: left; height: 24.7344px;">Week 34</td>
<td style="width: 29.2017%; border-style: dotted; border-width: 1px; text-align: left; height: 24.7344px;">starts August 19, 2024</td>
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<td style="width: 29.0798%; border-style: dotted; border-width: 1px; text-align: left; height: 24.7344px;">Week 35</td>
<td style="width: 29.2017%; border-style: dotted; border-width: 1px; text-align: left; height: 24.7344px;">starts August 26, 2024</td>
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<td style="width: 29.0798%; border-style: dotted; border-width: 1px; text-align: left; height: 24.7344px;">Week 36</td>
<td style="width: 29.2017%; border-style: dotted; border-width: 1px; text-align: left; height: 24.7344px;">starts September 2, 2024</td>
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<td style="width: 29.0798%; border-style: dotted; border-width: 1px; text-align: left; height: 27px;">Week 37</td>
<td style="width: 29.2017%; border-style: dotted; border-width: 1px; text-align: left; height: 27px;">starts September 9, 2024</td>
<td style="width: 41.7185%; height: 101.203px; border-style: dotted; border-width: 1px; text-align: left;" rowspan="7">Currently shipping</td>
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<td style="width: 29.0798%; border-style: dotted; border-width: 1px; text-align: left; height: 30px;">Week 38</td>
<td style="width: 29.2017%; border-style: dotted; border-width: 1px; text-align: left; height: 30px;">starts September 16, 2024</td>
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<td style="width: 29.0798%; border-style: dotted; border-width: 1px; text-align: left; height: 27px;">Week 39</td>
<td style="width: 29.2017%; border-style: dotted; border-width: 1px; text-align: left; height: 27px;">starts September 23, 2024</td>
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<tr style="height: 27px;">
<td style="width: 29.0798%; border-style: dotted; border-width: 1px; text-align: left; height: 27px;">Week 40</td>
<td style="width: 29.2017%; border-style: dotted; border-width: 1px; text-align: left; height: 27px;">starts September 30, 2024</td>
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<tr style="height: 21px;">
<td style="width: 29.0798%; border-style: dotted; border-width: 1px; text-align: left; height: 21px;">Week 41</td>
<td style="width: 29.2017%; border-style: dotted; border-width: 1px; text-align: left; height: 21px;">starts October 7, 2024</td>
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<tr style="height: 21px;">
<td style="width: 29.0798%; border-style: dotted; border-width: 1px; text-align: left; height: 21px;">Week 42</td>
<td style="width: 29.2017%; border-style: dotted; border-width: 1px; text-align: left; height: 21px;">starts October 14, 2024</td>
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<td style="width: 29.0798%; border-style: dotted; border-width: 1px; text-align: left; height: 21px;">Week 43</td>
<td style="width: 29.2017%; border-style: dotted; border-width: 1px; text-align: left; height: 21px;">starts October 21, 2024</td>
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<tr style="height: 21px;">
<td style="width: 29.0798%; border-style: dotted; border-width: 1px; text-align: left; height: 21px;">Week 44</td>
<td style="width: 29.2017%; border-style: dotted; border-width: 1px; text-align: left; height: 21px;">starts October 28, 2024</td>
<td style="width: 41.7185%; border-style: dotted; border-width: 1px; text-align: left;" rowspan="4">From week 48 (starts November 25, 2024)</td>
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<td style="width: 29.0798%; border-style: dotted; border-width: 1px; text-align: left;">Week 45</td>
<td style="width: 29.2017%; border-style: dotted; border-width: 1px; text-align: left;">starts November 4, 2024</td>
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<td style="width: 29.0798%; border-style: dotted; border-width: 1px; text-align: left;">Week 46</td>
<td style="width: 29.2017%; border-style: dotted; border-width: 1px; text-align: left;">starts November 11, 2024</td>
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<td style="width: 29.0798%; border-style: dotted; border-width: 1px; text-align: left;">Week 47</td>
<td style="width: 29.2017%; border-style: dotted; border-width: 1px; text-align: left;">starts November 18, 2024</td>
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<p></p>
<p> </p>
<h3><span style="font-size: 20px;">Current lead time estimates for new orders</span></h3>
<p><span style="color: #e67e23;"><strong>Updated: November 18th, 2024 </strong></span></p>
<p><em>The dates are only an estimation at the date of update, specified above, and rely on the actual</em> production. <em>We're doing our best but please be aware that it can shift for the lead time products. We will update here and on the product pages accordingly.</em></p>
<p>The lead time estimate applies to standalone products, other products in the order may increase the lead time.</p>
<p>If you've ordered a product in a bundle, the lead time of the order is set based on the product in the bundle with the longest lead time.</p>
<p> </p>
<p></p>
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<td style="height: 27.922px; width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center;">
<h4>Product</h4>
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<td style="height: 27.922px; width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center;">
<h4>Lead time</h4>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p><strong>Original Prusa XL Enclosure<br /></strong><em>(standalone)</em><strong><br /></strong></p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p><strong>In stock</strong></p>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p><strong>Advanced Filtration System <br /></strong>(for Original Prusa Enclosure)</p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p><strong>In stock</strong></p>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p><strong>MK4 to MK4S upgrade<br /></strong>/MK4S upgrade for versions with old xLCD</p>
</td>
<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p><strong>1-2 weeks</strong></p>
</td>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p><strong>MK3.9 to MK3.9S upgrade</strong></p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p><strong>In stock</strong></p>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>MK3S/+ to MK4S upgrade</strong></p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>1-2 weeks</strong></p>
</td>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center;">
<p><strong>MK3S/+ to MK3.9S upgrade</strong></p>
</td>
<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center;">
<p><strong>In stock</strong></p>
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<tr style="height: 51px;">
<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>MK3S/+ to MK3.5S upgrade</strong></p>
</td>
<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>In stock</strong></p>
</td>
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<tr style="height: 72px;">
<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p><strong>Original Prusa MMU3 upgrade kit (for MK4S/MK3.9S)</strong></p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p><strong>1-2 weeks</strong></p>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>MMU3 assembled unit (for MK4S/MK3.9S) </strong></p>
</td>
<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>1-2 weeks</strong></p>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>MMU3 assembled unit (for MK4/MK3.9)</strong></p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>In stock</strong></p>
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<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>MMU3 assembled unit (for MK3.5S/MK3.5) </strong></p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>In stock</strong></p>
</td>
</tr>
<tr style="height: 51px;">
<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>MMU3 assembled unit (for MK3S+) </strong></p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 51px;">
<p><strong>In stock</strong></p>
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<tr style="height: 72px;">
<td style="width: 48.3436%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p><strong>Original Prusa MMU2S to MMU3 upgrade<br />for MK4S/MK3.9S</strong></p>
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<td style="width: 51.6564%; border-style: dotted; border-width: 1px; text-align: center; height: 72px;">
<p><strong>1-2 weeks</strong></p>
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</table>
<p>You can find your order shipping date in the order detail section in our shop.</p>
<div class="note-callout">All products purchased in our <a href="https://shop.prusa3d.com/">online store</a> are currently being shipped from the<strong> Czech Republic, </strong>a member state of the <strong>European Union, customs charges may apply for shipments to countries outside of the EU!</strong> Please see our advisory article <a href="http://help.prusa3d.com/article/vat-value-added-tax-customs-fees_1505#orders-outside-eu">here</a>.</div>

Shipping information

Infill patterns

<p>The First Layer Calibration is used to calibrate the distance between the tip of the nozzle and the print surface. The aim is to adjust the nozzle height until the extruded plastic sticks nicely to the bed and you can see that it is being slightly squished.</p>
<p>The printers assembled in the Prusa factory are already fine-tuned and this calibration is needed only in case you build the kit version at home or change the nozzle. The First Layer Calibration is part of the Wizard (last step of the XYZ-Calibration). You can also recalibrate the first layer later on from the <em>LCD-menu - Calibration - First Layer Calibration</em>. During this process, rotate the knob to manually adjust the distance between the nozzle and the bed, while the printer is printing a zig-zag pattern.</p>
<div class="warning-callout">As <strong>each type of sheet (smooth, satin, and textured) has a different thickness</strong> you must use a different First layer calibration for each of them. For this, we have a convenient feature called <a href="http://help.prusa3d.com/article/steel-sheet-profiles_1955">Steel sheet profiles</a>.</div>
<p>With a newly assembled printer, you will start at zero and move into a negative (-) value, reducing the distance between nozzle and heat bed. The initial zero-value is set by the P.I.N.D.A./SuperPINDA. position. <strong>Turn the knob counter-clockwise to bring the nozzle closer to the bed and moving the value away from zero. </strong>The value is unique to each printer and it may also slightly change with time and use. You must, therefore, <strong>check visually when adjusting the height, not by a set value. </strong></p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/first_layer-768x433-1.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/first_layer-768x433-1-600x338.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/first_layer-768x433-1-300x169.jpg 300w" alt="" width="600" height="338" loading="lazy" /></p>
<p>The first layer calibration being set incorrectly can lead to various issues. With the nozzle too far from the print surface, you risk your print not sticking properly, which can result in a <a href="http://help.prusa3d.com/article/extruder-blob_2005">blob</a>. On the other side, if set too close, you can experience extrusion problems and <a href="http://help.prusa3d.com/article/clogged-nozzle-hotend-mk3-5-s-mk3s-mk2-5s_2008">clogging</a> and poor print quality, <strong>or even damage to the hardware, like the <a href="http://help.prusa3d.com/article/flexible-steel-sheets-guidepost_2195">Flexible steel sheet</a> due to the print sticking too much.</strong> It is therefore <strong>important to get this right.</strong></p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-01.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-01-300x62.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-01-600x125.jpg 600w" width="600" height="125" loading="lazy" data-hd-align="center" /></p>
<p>Before you proceed, make sure that the print surface (satin, smooth, or textured steel-sheet) is clean. You can find information on how to clean it in <a href="http://help.prusa3d.com/article/first-layer-issues_1804">PEI print surface preparation</a>. There are some small differences between how it should look on the textured and smooth steel sheet. We will, therefore, present pictures and guidelines for both, starting with the smooth sheet.</p>
<div>
<div class="note-callout" style="text-align: center;"><strong>Turn the knob counter-clockwise to bring the nozzle closer to the bed.</strong></div>
</div>
<h3>Smooth sheet</h3>
<h4>Too high</h4>
<p><strong>You want the line flattened, but not squished.</strong> On the square at the end of the test line, you do not want any <strong>gaps between the lines (<span style="color: #e03e2d;">left picture</span>), which means it is too high. </strong>In that case, the value will be too close to zero</p>
<h4>Too low</h4>
<p>If the nozzle is set too low (<span style="color: #e03e2d;">right picture</span>) you will see the line squished completely flat and the end square will have <strong>ridges between the lines, which is a clear sign it is set too low</strong> and the value will be too far away from zero. When it is too low, the edges of the square can also start curling upwards. In the extreme, the filament will be spread so thin you will be able to see through the printed filament, leading to clogging of your hotend.</p>
<div class="warning-callout">Having the nozzle too low can cause the nozzle to damage your steel sheet. This is not covered by <a href="http://help.prusa3d.com/article/warranty_2288">Warranty</a>.</div>
<h4>Just right</h4>
<p>A correct adjustment will show you an even surface (<span style="color: #2dc26b;">center picture</span>), with no gaps between lines, nor ridges. As stated, the numeric value depends on the exact position of the P.I.N.D.A./SuperPINDA sensor, which will be unique to each machine and means nothing without a visual reference. <strong>However, a common range is from -0.400 to -1.500.</strong></p>
<p><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-02.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-02-300x119.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-02-600x238.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-02-768x305.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-02-800x318.jpg 800w" /></p>
<div class="note-callout">Adjusting it closer can in some cases improve adhesion. However, if you are having problems with adhesion, but your first layer calibration looks like the 'good' picture (<span style="color: #2dc26b;">center picture</span>), your problem lies somewhere else, like a dirty/greasy sheet, print-settings, bed leveling/XYZ calibration, or under-extrusion.</div>
<p><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-03fix-2.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-03fix-2-600x214.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-03fix-2-800x286.jpg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-03fix-2-300x107.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-03fix-2-768x274.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-03fix-2-1536x548.jpg 1536w, https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-03fix-2-2048x731.jpg 2048w" alt="" width="1121" height="400" loading="lazy" /></p>
<div class="warning-callout"><strong>You can not use the same first layer calibration if you swap between the Smooth and the textured sheet! </strong>For more information, please see <a href="http://help.prusa3d.com/article/steel-sheet-profiles_1955">Steel sheet profiles</a>.</div>
<h3>Textured sheet</h3>
<p>The textured sheets are thinner than the sheets with smooth PEI, therefore you need to move the nozzle bit closer, but you are seeking the same results as with the smooth sheet. Again, if <strong>it is set too low (<span style="color: #e03e2d;">right picture</span>) the filament can start curling up</strong> around the edges like it is not adhering. The numeric value will be too far from zero and must be adjusted back.</p>
<p>If set too high, you will see the line being round, and have gaps between the lines of the end-square. In this case, the value is too close to zero.</p>
<p><img decoding="async" title="https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-04-300x119.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-04-600x238.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-04-768x305.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-04-800x318.jpg 800w" src="https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-04.jpg" /></p>
<h3>Have a look at the nozzle</h3>
<p>A single layer is about 0.2 mm / 0.00787402 inch. Having a look at the nozzle and its distance to the sheet can also be helpful. However, measuring the printed layer with calipers is not a recommended method to calibrate the first layer.</p>
<p><img decoding="async" title="https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-05-300x119.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-05-600x238.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-05-768x305.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-05-800x318.jpg 800w" src="https://cdn.help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-05.jpg" /></p>
<h3>When to run the First layer calibration</h3>
<p>Generally, the <strong>first layer calibration</strong> should be performed every time there is a <strong>major change in the assembly.</strong> This includes changing the nozzle, extruder upgrades, or other updates to any axis. You should also run all calibrations if you move the printer to a different location.</p>
<div class="tip-callout">For First Layer Calibrations with other nozzle diameters than 0.4 mm, please see <a href="http://help.prusa3d.com/article/different-nozzle-types_2193#first-layer-calibration-of-other-nozzles">this article</a></div>
<h3>Other issues</h3>
<ul>
<li>If the width of the line varies across its length, you may have to do some <a href="http://help.prusa3d.com/article/bed-level-correction_2267">Bed Level Correction</a>.</li>
<li>If the nozzle comes in contact with the bed, the SuperPINDA/P.I.N.D.A. leveling sensor is not being triggered by the flexible steel sheet and must be physically moved lower in its holder. This will bring it closer to the level of the nozzle tip. You should make sure it is adjusted as instructed in the <a href="http://help.prusa3d.com/guide/9-preflight-check_76792">Preflight check</a> in the Assembly manual. <strong>If you move the leveling sensor you must redo the First layer calibration.</strong></li>
</ul>

First Layer Calibration (i3)

<div class="warning-callout">This is an&nbsp;<strong>advanced calibration</strong>, recommended only to&nbsp;<strong>experienced users</strong>.</div>
<p>The Extrusion Multiplier allows the fine-tuning of the extrusion flow rate - simply described as&nbsp;<strong>how much filament comes out of the nozzle</strong>. In other words, the&nbsp;<strong>Extrusion Multiplier</strong>&nbsp;setting in PrusaSlicer and the&nbsp;<strong>Flow rate</strong>&nbsp;setting in printer firmware are two ways to adjust the same thing, however, adjusting one of those two settings will not influence the value of the other.</p>
<p><strong>This procedure is not necessary with a new printer coming from the factory</strong>, but rather applies for specific applications and filaments. The ideal value is different for every type of material and every color. It can even differ from spool to spool. Bear this in mind if you change type and brand of filament often or use cheap no-name brands.</p>
<div class="note-callout">Total flow rate = <strong>Flow multiplier</strong> in firmware (M221) x <strong>Extrusion multiplier</strong> in PrusaSlicer. For those interested in diving deeper, PrusaSlicer uses the same <a href="https://manual.slic3r.org/advanced/flow-math">Flow math as Slic3r</a>.</div>
<h3><strong>How to spot an issue</strong></h3>
<p>This calibration is used to fix two common problems:</p>
<ul>
<li><strong>Overextrusion</strong> - Too much material is extruded (flow is too high). It causes scarring of bottom layers and unnecessary material buildup on top layers.</li>
<li><strong>Minor under extrusion</strong>&nbsp;- Not enough material is extruded (flow is too low). It causes small gaps that appear between layer lines or perimeters.</li>
</ul>
<p><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/under-ok-over.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/under-ok-over-600x282.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/under-ok-over-800x376.jpg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/under-ok-over-300x141.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/under-ok-over-768x361.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/under-ok-over-1536x721.jpg 1536w" alt="" width="852" height="400"></p>
<p><strong>Overextrusion</strong> is a common problem with many filament brands. It's especially problematic when you're trying to glue two parts of the model. <strong>If the top layer is over extruded, you'll end up with an uneven surface that will prevent a seamless connection between the two pieces.</strong></p>
<h3><strong>How to do the calibration</strong></h3>
<p>In PrusaSlicer, navigate to <span class="key">Filament Settings</span> and look for Extrusion Multiplier. The default setting (for PLA) is 1, this value represents a percentage, 1 = 100%, 0.95 = 95% etc. Usually, the adjusted values can be between 0.9 and 1.1. To adjust it, simply rewrite the value.</p>
<p><img decoding="async" style="max-height: 200px; display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusuki/prusuki-images/image-2019-1-15-12-55-6.png" data-hd-height="200px"></p>
<p>In the printer menu, during a print, go to the Tune menu and then choose Flow. Again, the usual values can range between 90 and 110, although that does not mean you can't go above or below that.</p>
<h4>Which method should I use?</h4>
<p>There are two methods you can use to calibrate the Extrusion Multiplier, and we'll cover both of them in this article:</p>
<ul>
<li><strong>Precise Method</strong>&nbsp; -&nbsp; using precision tools such as calipers or micrometers.</li>
<li><strong>Visual Method&nbsp;</strong>&nbsp;- an easy method based on observing the visual properties of your models.</li>
</ul>
<p>The choice of the method depends entirely on your preferences; in the end, both yield similar results. Even the visual method will enable you to have perfectly fitting parts with smooth &amp; flat top layers.</p>
<h4>Precise Method</h4>
<div class="note-callout">Please note that the following guide is based on <strong>default</strong> PrusaSlicer 0.4 nozzle profiles, with a layer height of 0.1mm - 0.2mm. This means that:<br />
- Nozzle size = 0.4<br />
- Extrusion width =&nbsp;0.45<br />
- Basic materials (PLA, ABS, PETG) Extrusion Multiplier = 1<br />
<strong>If you wish to calibrate the printer with a bigger/smaller nozzle or layer heights above 0.2, then you will need to adjust these values as well.</strong></div>
<ol>
<li>Download the <a href="https://cdn.help.prusa3d.com/wp-content/uploads/2021/04/cube-40-40-40.zip">Precision Method Cube STL</a>.</li>
<li>Slice it using the Vase Mode and your most-often used layer height and print it. You can find Vase mode (Print Settings →&nbsp; Layers and perimeters →&nbsp; Spiral vase).</li>
<li>Make three or more measurements in the middle of each wall and calculate the overall average thickness.</li>
<li>Calculate the extrusion multiplier using the following formula: <strong>Extrusion multiplier = (Extrusion width (0.45) / Average measured wall thickness)</strong>.</li>
<li>Adjust the Extrusion Multiplier in Filament Settings → Filament</li>
<li>Re-print the cube with new settings and go back to step 3 if necessary.</li>
</ol>
<p><img decoding="async" style="max-height: 220px; display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusuki/prusuki-images/micrometer-small-jpg.JPG" height="400" data-hd-height="220px"></p>
<div class="warning-callout">Please note that cheap digital calipers may not be accurate enough to make reliable measurements of a single perimeter wall.</div>
<h4>Visual Method</h4>
<p>This method does not require any tools, only your sight. The point is to make sure your top layers are <strong>smooth</strong>, <strong>shiny,</strong> and without <strong>scarring or filament buildup</strong> near the perimeters.</p>
<p><img decoding="async" loading="lazy" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/destiky6.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/destiky6-600x374.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/destiky6-800x499.jpg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/destiky6-300x187.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/destiky6-768x479.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/destiky6-1536x958.jpg 1536w" alt="" width="641" height="400"></p>
<ol>
<li>Download the <a href="https://cdn.help.prusa3d.com/wp-content/uploads/2021/04/visual-method-cube.zip">Visual Method Cube.stl</a></li>
<li>Slice it using the default Prusa PLA presets at 0.20mm layer height and print it.</li>
<li>Inspect the top layer of your cube visually and with the tip of the finger.</li>
<li>If the top is under extruded or not smooth, then re-adjust the Extrusion Multiplier accordingly by 1-2%.</li>
<li>Repeat the steps above as long as needed.</li>
</ol>
<p>If there is&nbsp;<strong>too much material</strong>&nbsp;near the perimeters,&nbsp;<strong>decrease</strong>&nbsp;the Extrusion Multiplier value.</p>
<p><img decoding="async" style="max-height: 390px; margin-left: auto; margin-right: auto; display: block;" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusuki/prusuki-images/buildu.jpg" data-hd-height="390px" data-hd-align="left"></p>
<p>If there are&nbsp;<strong>visible gaps</strong>&nbsp;between layer lines,&nbsp;<strong>increase</strong> the Extrusion Multiplier value. (Microscopic gaps near the perimeters are OK.)</p>
<p><img decoding="async" style="max-height: 430px; margin-left: auto; margin-right: auto; display: block;" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusuki/prusuki-images/gaps.jpg" data-hd-height="430px" data-hd-align="left"></p>


Extrusion multiplier calibration

<div><strong><img decoding="async" loading="lazy" style="float: right;" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-600x600.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-768x768.jpg 768w" alt="" width="225" height="225"></strong></div>
<h3>Basic info</h3>
<div><strong>PETG</strong> is one of the most easily printable materials, it is <strong>inexpensive and suitable for beginners</strong>. Relatively high tenacity and temperature resistance make it <strong>suitable for printing technical parts</strong> (for example parts of our printers).</div>
<div>&nbsp;</div>
<div><strong>Recommended nozzle temperature:</strong> 230 °C for the first layer, 240 °C for the other layers</div>
<div>&nbsp;</div>
<div><strong>Recommended bed temperature:</strong> 85 °C for the first layer, 90 °C for the other layers</div>
<div>&nbsp;</div>
<div><strong>Heatbed:</strong> Using powder-coated TXT or satin sheet is highly recommended. Printing on smooth PEI surface might damage the sheet.</div>
<h3>Description</h3>
<div>
<p><a href="https://www.prusa3d.com/category/prusament-petg/"><strong data-stringify-type="bold">PETG</strong></a> (Polyethylene Terephthalate modified with Glycol) is a commonly used technical material, popular among 3D printer users for its <strong>low price and good printability</strong>. It’s tenacious, with good temperature resistance; PETG is most commonly used for printing various mechanical parts, holders, clamps, and waterproof parts (thanks to great layer adhesion).</p>
<p>PETG has a glossy surface, adheres greatly to a print sheet, and <strong>does not shrink or warp</strong> (it has very little thermal expansion), therefore it’s suitable for printing large models. Plus, its high tenacity and flexibility often <strong>prevent it from breaking.</strong> Due to good temperature resistance, PETG parts are suitable both for interior and most exterior use (with temperatures below 80 °C). <strong>Parts of our printers are made of PETG!</strong></p>
<p>The letter G in PETG means that it’s modified with glycol during the manufacturing process. Glycol makes PET less brittle, easier to print, and more transparent for translucent prints. Of course, you can print also with PET filaments without glycol. However, printing with only PET is challenging and does not offer any advantage whatsoever.</p>
<div class="warning-callout">Even though PETG in itself may be considered <a href="http://help.prusa3d.com/article/food-safe-fdm-printing_112313">food-safe</a>, it consists of layers, as every 3D print, in which bacteria can grow over time. You can prevent this by applying a <strong>food-safe(epoxy) coating.</strong> Also, a stainless-steel nozzle should be used for if food is the intended application.</div>
<p>Although <strong>PETG</strong> is frequently used in <strong>food industry</strong> and is considered <strong>food-safe</strong>, we do not recommend it (or any other filament) for printing dishes or other stuff that comes into direct contact with food. The main reason is tiny print layer surface grooves that can support numerous bacterial colonies. But if you still want 3D printed dishes, we suggest <strong>applying a special layer</strong> that seals the surface (food-safe coating) and printing with a clean steel nozzle.</p>
<p>Some of the manufacturers <strong>enrich PETG with various additives</strong> and sell these materials under different names. For example, Spoolworks EDGE by E3D is modified PET/Copolyester Blend with additives. The goal is to acquire better visual qualities, surface and layer adhesion, etc.</p>
<p>To compare supported material properties, see our <a href="https://help.prusa3d.com/en/materials">material table.</a></p>
</div>
<table class="striped">
<tbody>
<tr>
<th>
<p>Pros</p>
</th>
<th>
<p>Cons</p>
</th>
</tr>
<tr>
<td>
<p>✔ Easy to print</p>
</td>
<td>
<p>✖ Possibility of stringing</p>
</td>
</tr>
<tr>
<td>
<p>✔ Good layer adhesion</p>
</td>
<td>
<p>✖ Poor bridging and overhangs</p>
</td>
</tr>
<tr>
<td>
<p>✔ Tough and durable</p>
</td>
<td>
<p>✖ Not great for printing detailed parts</p>
</td>
</tr>
<tr>
<td>
<p>✔ Low warping</p>
</td>
<td>
<p>✖ Bonds strongly to the print surface</p>
</td>
</tr>
<tr>
<td>✔ High temperature-resistance</td>
<td>
<p>✖ Soluble in dangerous chemicals</p>
</td>
</tr>
<tr>
<td>✔ Water and humidity resistant</td>
<td>
<p>✖ Supports are hard to remove</p>
</td>
</tr>
</tbody>
</table>
<h3>Best use</h3>
<p>PETG is used universally but is especially suitable for mechanical parts for both indoor and outdoor use. We use PETG to print parts for our printers! Plastic bottles are also made from this kind of material.</p>
<h3>Tips for successful printing</h3>
<p><strong>Temperature settings and cooling</strong></p>
<p>Unlike PLA, <strong>PETG requires a heated bed (85 °C).</strong> Its bridging- and overhang-behavior is usually worse, plus it is prone to stringing. Stringing can be moderated with higher retractions and lower nozzle temperature, but we suggest <strong>using the PrusaSlicer profiles that should work fine.</strong> It’s important to <strong>cool the PETG print</strong> - this helps to keep the model detailed and prevents stringing and oozing. But if you want the model to be as tough as possible, try to turn off the print fan. Higher filament temperature improves merging between layers which leads to better mechanical resistance. Otherwise, we recommend printing the first few layers with the print fan off to prevent deformation, then with the fan running at half its power.</p>
<div class="warning-callout"><strong>Do not print on the smooth PEI sheet</strong> as the adhesion may be too strong!</div>
<p><strong>Print surface preparation</strong></p>
<p>Make sure the print surface is clean, as described in <a href="http://help.prusa3d.com/article/first-layer-issues_1804">our dedicated article</a>. It is advisable to use one of the <strong>powder-coated print sheets. Do not print on the smooth PEI sheet</strong> as the adhesion may be too strong! If you decide to use the smooth PEI sheet anyway, apply a glue stick on it before printing.</p>
<p><strong>Adding more perimeters for more solid parts</strong></p>
<p>If you want to print truly solid parts, <strong>try to increase the number of perimeters</strong> instead of adding more infill.</p>
<h3>Postprocessing</h3>
<p>PETG can be easily sanded both dry and wet.</p>
<p><strong>Dissolving PETG</strong></p>
<p><strong>Dissolving and smoothing PETG</strong> is possible only in a laboratory by skilled lab workers using <strong>dangerous chemicals</strong> (Dichloromethane).</p>
<h3>Sample prints</h3>
<table style="border-collapse: collapse; width: 100%; height: 954px;" border="0">
<tbody>
<tr style="height: 300px;">
<td style="width: 48.805%; height: 300px;"><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-1-1.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-1-1-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-1-1-600x600.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-1-1-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-1-1-768x768.jpg 768w" alt="" width="800" height="800"></td>
<td style="width: 48.805%; height: 300px;"><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-jet-black-1kg.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-jet-black-1kg-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-jet-black-1kg-600x600.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-jet-black-1kg-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-jet-black-1kg-768x768.jpg 768w" alt="" width="800" height="800"></td>
</tr>
<tr style="height: 18px;">
<td style="width: 48.805%; height: 18px; text-align: center;"><em>MMU (Multi-Material Unit)</em></td>
<td style="width: 48.805%; height: 18px; text-align: center;"><em>Electronics cover and other printer parts</em></td>
</tr>
<tr style="height: 300px;">
<td style="width: 48.805%; height: 300px;"><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-2.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-2-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-2-600x600.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-2-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-2-768x768.jpg 768w" alt="" width="800" height="800"></td>
<td style="width: 48.805%; height: 300px;"><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-3.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-3-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-3-600x600.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-3-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-3-768x768.jpg 768w" alt="" width="800" height="800"></td>
</tr>
<tr style="height: 18px;">
<td style="width: 48.805%; height: 18px; text-align: center;"><em>Ukulele</em></td>
<td style="width: 48.805%; height: 18px; text-align: center;"><em>Various mechanical parts</em></td>
</tr>
<tr style="height: 300px;">
<td style="width: 48.805%; height: 300px; text-align: center;"><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-1.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-1-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-1-600x600.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-1-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-1-768x768.jpg 768w" alt="" width="800" height="800"></td>
<td style="width: 48.805%; height: 300px; text-align: center;"><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-600x600.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-768x768.jpg 768w" alt="" width="800" height="800"></td>
</tr>
<tr style="height: 18px;">
<td style="width: 48.805%; height: 18px; text-align: center;"><em>Electronic parts</em></td>
<td style="width: 48.805%; height: 18px; text-align: center;"><em>Boxes and organizers</em></td>
</tr>
</tbody>
</table>


PETG

Original Prusa i3 MK3S/MK3S+ to MK3.5S upgrade

Assembly manuals

Basic calibration

Advanced calibration

All information you need to know to learn how to calibrate your 3D printer to achieve perfect prints.

Calibration

Printer description

Printer features

FAQs and other useful information you might be interested in before or after making your purchase at shop.prusa3d.com

General Information

Basic overview of your 3D printer and it's features, plus general Prusa Research info.

About your printer

3D models

Material guide

Printer maintenance

Prusa Connect & PrusaLink

In this section, you can find material guides, printer troubleshooting and general info about using your printer.

Using the printer

Print Quality Troubleshooting

QR Error codes

Printer troubleshooting

Description of how to recognize and solve common problems, especially hardware and electronics related.

Troubleshooting

Nozzles

Octoprint

Learn about different nozzles, Raspberry Pi connection, Octoprint and more.

3rd party accessories & Other projects

About PrusaSlicer

Configuration and profiles

User interface

Top toolbar

Print settings

Filament settings

Advanced features

The official documentation for the PrusaSlicer slicing software. From basic configuration to advanced settings like modifier meshes.

PrusaSlicer

1. Introduction

2. Parts check

3. Printer dissasembly

4. xBuddy assembly

5. xLCD & PSU assembly

6. Heatbed upgrade

7. Extruder & connectivity upgrade

8. Preflight check

Manual changelog MK3.5S upgrade

<p>Loose belts would cause a printer to malfunction and prevent proper printing. It can cause <a href="http://help.prusa3d.com/article/layer-shifting_2020">Layer shifting</a>, <a href="http://help.prusa3d.com/article/ghosting_1801">Ghosting</a>, or other print abnormalities like getting an irregular shape instead of a perfect circle when printing a cylinder. <strong>The Y-axis belt is located under the heatbed, X-axis belt moves the print head. All adjustments are done with the 2.5mm Allen key. </strong></p>
<h3>Checking belt tension</h3>
<h4>New procedure - Belt tuner app</h4>
<p>Follow the instructions in the video below, to adjust the belt tightness using our <a href="https://belt.connect.prusa3d.com/">belt tuner</a>. </p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/05/342c4a2c9bf82513.jpg" alt="" width="500" height="375" loading="lazy" /></p>
<p style="text-align: center;"><iframe src="https://www.youtube.com/embed/oeq2MVxE_H8" width="560" height="314" allowfullscreen="allowfullscreen" loading="lazy"></iframe></p>
<h4>Old procedure</h4>
<p>On MK3/S/+, it is possible to check the <strong>Belt Status</strong> numbers via <em>LCD Menu -&gt; Support -&gt; Belt Status</em>. </p>
<p><span style="color: #000000;">While there is not a precise ideal value, from our experience, the best approximate value is around 250 on the X-axis, and 275 on the Y-axis, with an optimal range at +-15 from these values on either axis. </span></p>
<p><span style="color: #000000;">The value does not represent a physical quantity, but an arbitrary number inversely proportional to the motor load. The values are with the consideration that the assembly is good and that the parts are in good condition and properly lubricated. Values may not be accurate if there are other problems. </span></p>
<ul>
<li>If your value is <strong>under</strong> (or close to) 240, you need to <strong>loosen</strong> the belt</li>
<li>If your value is <strong>over</strong> (or close to) 290, you need to <strong>tighten</strong> the belt</li>
<li>The values are updated every time you run the Selftest or run the belt test in <em>LCD menu -&gt; Calibration -&gt; Belt test</em>. </li>
</ul>
<p><span style="color: #000000;">Other MK-series models</span> do not have the belt status option. The clue we can give you is that the belt should sound roughly like a low bass string when plucked. It should be possible to pinch the two sides together with your thumb and index finger, but you should feel a little bit of resistance.</p>
<div class="warning-callout">The plastic parts holding the belts can get loose over time.</div>
<p>Another way is to use the technique described in <a href="http://help.prusa3d.com/guide/5-e-axis-assembly_28536#30816">this step</a> of the assembly manual to test if the pulley is correctly tightened and if the belt is not too loose. Hold the X-axis motor shaft with pliers (take advantage of the flat part of the shaft) to fix it in place (<strong><span style="color: #b96ad9;">purple circle</span></strong>), then try to move the extruder by hand. <strong>You should see no slack on the belt as a result of pushing on the extruder.</strong> The same procedure can be applied to test the Y-axis pulley and belt.</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/prusuki/prusuki-images/2019-08-21-16-07-05-f-jmg-pa-bdtv-ruqf-11-full-1600-1200.jpg" alt="" width="600" height="415" loading="lazy" /></p>
<h3>X-axis belt</h3>
<h4>Slight adjustments MK3S</h4>
<p>Loosen the two front-facing screws and make sure they have space to their right to move (<span style="color: #f1c40f;"><strong>yellow circles</strong></span>). While assisting with the rotation of the motor with your hand, tighten the M3x18 screw on top of the X-end-motor (<span style="color: #b96ad9;"><strong>purple arrow</strong></span>).</p>
<p>After each turn or two check the tension in the belt by pressing them together. For optimal performance, the belt must need some force to press together with your fingers (<span style="color: #2dc26b;">green arrows</span>). <strong>Move the extruder all the way to the X-end-idler and try the belt tension in the middle of the X-axis.</strong></p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/d1a9b24b68e0121e_painted.jpeg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/d1a9b24b68e0121e_painted-533x400.jpeg 533w, https://cdn.help.prusa3d.com/wp-content/uploads/d1a9b24b68e0121e_painted-800x600.jpeg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/d1a9b24b68e0121e_painted-300x225.jpeg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/d1a9b24b68e0121e_painted-768x576.jpeg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/d1a9b24b68e0121e_painted-1536x1152.jpeg 1536w" alt="" width="600" height="450" loading="lazy" /></p>
<h4>Slight adjustments MK3S+, MK3.5/S, MK3.9/S, MK4/S</h4>
<ol>
<li>Slightly release all the screws holding the motor, otherwise, the "tensioner" won't work as the motor must be able to move (left picture).</li>
<li>Using the ball end of the Allen key, start tightening the screw on the rear side of the X-end-motor, but after each turn or two check the tension in the belt (right picture).</li>
<li>When you achieve optimal tension, please tighten the screws again (left picture).</li>
</ol>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.805%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2020/11/da45b9e5fe1a6ec4_painted.jpeg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/2020/11/da45b9e5fe1a6ec4_painted-533x400.jpeg 533w, https://cdn.help.prusa3d.com/wp-content/uploads/2020/11/da45b9e5fe1a6ec4_painted-800x600.jpeg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/2020/11/da45b9e5fe1a6ec4_painted-300x225.jpeg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/2020/11/da45b9e5fe1a6ec4_painted-768x576.jpeg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/2020/11/da45b9e5fe1a6ec4_painted-1536x1152.jpeg 1536w" alt="" width="400" height="300" loading="lazy" /></td>
<td style="width: 48.9057%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2020/11/4d946176a9a518fc_painted.jpeg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/2020/11/4d946176a9a518fc_painted-533x400.jpeg 533w, https://cdn.help.prusa3d.com/wp-content/uploads/2020/11/4d946176a9a518fc_painted-800x600.jpeg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/2020/11/4d946176a9a518fc_painted-300x225.jpeg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/2020/11/4d946176a9a518fc_painted-768x576.jpeg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/2020/11/4d946176a9a518fc_painted-1536x1152.jpeg 1536w" alt="" width="400" height="300" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h4>Large adjustments MK3/S/+ or MK3.5/S</h4>
<p>If a slight adjustment is not sufficient you must adjust it at the belt holder. This is found on the back of the extruder and requires a little disassembly.</p>
<p>First, remove the two top screws from the motor-holder to let the belt have some slack in order to easier manipulate the belt.</p>
<ol>
<li>Snip the zip-ties on the back of the extruder (<span style="color: #e03e2d;"><strong>red arrows</strong></span>), which are securing the hotend wires <strong>and</strong> the ones securing the cable wrap.</li>
</ol>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/Adjusting-belt-tension-MK3S-03.png" alt="" width="600" height="450" loading="lazy" /></p>
<ol start="2">
<li style="counter-increment: li 1;">Unscrew the 4 screws circled in the picture below.</li>
</ol>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/Adjusting-belt-tension-MK3S-04.png" alt="" width="600" height="450" loading="lazy" /></p>
<ol start="3">
<li style="counter-increment: li 2;">Carefully pull the back plate loose, making sure the wires are safe, and turn the whole plate to the left or right.</li>
</ol>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/Adjusting-belt-tension-MK3S-05.jpg" alt="" width="600" height="574" loading="lazy" /></p>
<ol start="4">
<li style="counter-increment: li 3;">You now have access to where you mount the belts. Put a mark on the belt with a pen or marker as close to the plastic part as possible, so you know how it was adjusted. Now, take out the belt from the mount and move it in 1-2 teeth.</li>
</ol>
<div class="tip-callout">It may be necessary to cut off the last tooth of the belt.</div>
<ol start="5">
<li style="counter-increment: li 4;">Place the back plate back on, secure the screws, starting with the center one for alignment, then put on new zip-ties.</li>
<li>Re-tighten the screws on the x-motor, securing it. Adjust it tighter if needed.</li>
</ol>
<h4>Large adjustments MK4/S, MK3.9/S</h4>
<ol>
<li>Loosen the three indicated screws covering the X-carriage. Carefully take out the X-cover-back.
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/04/96f49f4aee27a2e4c92ed6d0dd7ff4c9_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Adjusting belt tension (review)" alt="" width="600" height="400" loading="lazy" /></p>
</li>
<li>You now have access to where you mount the belt. Put a mark on the belt with a pen or marker as close to the plastic part as possible, so you know how it was adjusted. Now, take out the belt from the mount and move it in 1-2 teeth.</li>
</ol>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/04/5d0b7637d19fdb682ff706171280e0fb.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Adjusting belt tension (review)" alt="" width="600" height="450" loading="lazy" /></p>
<h3>Y-axis belt</h3>
<h4>Slight adjustments</h4>
<p>On the front plate of the printer's frame, behind the LCD module, you will find the printed Y-axis belt idler. This is held by two M3X10 screws (<span style="color: #b96ad9;"><strong>purple arrow</strong></span>), going through the front plate.</p>
<p>If you have a gap between the idler part and the front plate of the frame (<span style="color: #236fa1;"><strong>blue arrows</strong></span>) you can tighten the belt by using your 2.5 mm Allen key to turn the screws clockwise (<span style="color: #b96ad9;"><strong>purple arrow</strong></span>), closing the gap.</p>
<p>The easiest way to access the screws is from below, by moving the printer to the edge of its table, with the LCD module sticking out. You now have access to the bolts from below the LCD module.</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/73fa58fb081ffbfa_painted.jpeg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/73fa58fb081ffbfa_painted-583x400.jpeg 583w, https://cdn.help.prusa3d.com/wp-content/uploads/73fa58fb081ffbfa_painted-800x549.jpeg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/73fa58fb081ffbfa_painted-300x206.jpeg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/73fa58fb081ffbfa_painted-768x527.jpeg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/73fa58fb081ffbfa_painted-1536x1053.jpeg 1536w" alt="" width="600" height="411" loading="lazy" /></p>
<h4>Large adjustments</h4>
<p>If a slight adjustment is not sufficient you must adjust it at the belt holder. There are two main types of the Y-axis belt holder, one adjustable and one fixed. The adjustable belt holder was introduced in the first quarter of 2019, with the S-upgrade for the Original Prusa MK3, and is also featured on the Original Prusa MK4. Adjustments for this are explained in '<strong>Method 1</strong>'. For an earlier Original Prusa MK3, follow '<strong>Method 2</strong>', for the fixed belt holder.</p>
<h4>Method 1 - Adjustable belt holder</h4>
<div class="tip-callout">The Original Prusa MK4/S has a different design than in the pictures, but the procedure is the same. </div>
<ol>
<li>Unplug the printer and lay it over on the side of the PSU.</li>
<li>Below the bed carriage, you will find the belt holder. Loosen the right screw by turning it <strong>counterclockwise</strong> (<span style="color: #e67e23;"><strong>orange circle</strong></span> left picture).</li>
<li>Turn the screw going through the two halves of the belt holder (<span style="color: #b96ad9;"><strong>purple arrow</strong></span> right picture). Turn <strong>clockwise</strong> to tighten the belt, moving the two halves together (<span style="color: #236fa1;"><strong>blue arrows</strong></span>).</li>
<li>When at the correct tension, secure the right half of the belt holder again by turning the screw from step 2 clockwise (<span style="color: #e67e23;"><strong>orange circle</strong></span> left picture).</li>
</ol>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.8106%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/b0f4fab2c260d687_painted.jpeg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/b0f4fab2c260d687_painted-533x400.jpeg 533w, https://cdn.help.prusa3d.com/wp-content/uploads/b0f4fab2c260d687_painted-800x600.jpeg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/b0f4fab2c260d687_painted-300x225.jpeg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/b0f4fab2c260d687_painted-768x576.jpeg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/b0f4fab2c260d687_painted-1536x1152.jpeg 1536w" alt="" width="400" height="300" loading="lazy" /></td>
<td style="width: 48.8106%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/fdec3d592f278afe_painted.jpeg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/fdec3d592f278afe_painted-533x400.jpeg 533w, https://cdn.help.prusa3d.com/wp-content/uploads/fdec3d592f278afe_painted-800x600.jpeg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/fdec3d592f278afe_painted-300x225.jpeg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/fdec3d592f278afe_painted-768x576.jpeg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/fdec3d592f278afe_painted-1536x1152.jpeg 1536w" alt="" width="400" height="300" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h4>Method 2 - Fixed belt holder</h4>
<ol>
<li>Unplug the printer and lay it over on the side of the PSU.</li>
<li>Detach the belt-idler in order to easier manipulate the belt (<strong><span style="color: #b96ad9;">purple arrows</span></strong>). <em>Detaching the idler completely may not be necessary, but will make it easier to adjust the belt in the next step.</em></li>
</ol>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/e5390e0a76daf6dc_painted.jpeg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/e5390e0a76daf6dc_painted-533x400.jpeg 533w, https://cdn.help.prusa3d.com/wp-content/uploads/e5390e0a76daf6dc_painted-800x600.jpeg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/e5390e0a76daf6dc_painted-300x225.jpeg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/e5390e0a76daf6dc_painted-768x576.jpeg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/e5390e0a76daf6dc_painted-1536x1152.jpeg 1536w" alt="" width="600" height="450" loading="lazy" /></p>
<ol start="3">
<li style="counter-increment: li 2;">Set a mark on the belt so you know how much you are moving it. Now take out the belt of the top slot, and move it in 1-2 teeth (<strong><span style="color: #236fa1;">blue arrow</span></strong>) before pushing it back into the slot (<strong><span style="color: #2dc26b;">green arrows</span></strong>).</li>
</ol>
<p style="text-align: center;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/10714ac443ad0a9c_painted.jpeg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/10714ac443ad0a9c_painted-533x400.jpeg 533w, https://cdn.help.prusa3d.com/wp-content/uploads/10714ac443ad0a9c_painted-800x600.jpeg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/10714ac443ad0a9c_painted-300x225.jpeg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/10714ac443ad0a9c_painted-768x576.jpeg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/10714ac443ad0a9c_painted-1536x1152.jpeg 1536w" alt="" width="600" height="450" loading="lazy" /><em>Your belt mount may look slightly different, being another iteration, but the procedure remains the same.</em></p>
<ol start="4">
<li style="counter-increment: li 3;">Re-attach the belt-idler with its two M3x10 screws through the frame (<strong><span style="color: #b96ad9;">purple arrow</span></strong>). Leave a gap with the frame, for slight adjustments (<strong>blue arrows</strong>). </li>
</ol>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/73fa58fb081ffbfa_painted.jpeg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/73fa58fb081ffbfa_painted-583x400.jpeg 583w, https://cdn.help.prusa3d.com/wp-content/uploads/73fa58fb081ffbfa_painted-800x549.jpeg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/73fa58fb081ffbfa_painted-300x206.jpeg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/73fa58fb081ffbfa_painted-768x527.jpeg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/73fa58fb081ffbfa_painted-1536x1053.jpeg 1536w" alt="" width="600" height="411" loading="lazy" /></p>

Adjusting belt tension (MK4/S, MK3.9/S, MK3.5/S, MK3/S/+)

<p>The Original Prusa MK2.5/S, MK3/S/+, and MK3.5/S use the E3D V6 Hotend. Any nozzle that is compatible with the E3D V6 Hotend can be installed on it. The stock nozzle that accompanies the printer is an E3D V6 0.4 mm brass nozzle, but other types and <a href="https://blog.prusaprinters.org/everything-about-nozzles-with-a-different-diameter_8344/">diameters</a> can be used as well. <strong>The following procedure applies to all nozzles, except the Olsson Ruby.</strong></p>
<div class="warning-callout"><strong>To replace the Olsson Ruby nozzle,</strong> follow the instructions on the <a href="https://support.3dverkstan.se/article/66-the-olsson-ruby-instructions-for-use">official 3DVERKSTAN website</a>. Otherwise, you could damage it!</div>
<h3>Why change the nozzle?</h3>
<p>There might be two main reasons for replacing the nozzle:</p>
<ul>
<li>The nozzle is worn out and needs a replacement.</li>
<li>You want to print using a different nozzle type, and/or diameter.</li>
</ul>
<div class="tip-callout">Unless you print abrasive materials with a brass nozzle, the stock brass nozzle will last you many hundreds of printing hours. Changing a relatively new nozzle to resolve a clog is not the solution!</div>
<div>The stock 0.4mm Nozzle installed on the Original Prusa i3 printers <a href="https://www.prusa3d.com/product/nozzle-e3d-v6-0-4-mm/">can be found in the eshop</a>. We also offer <a href="https://www.prusa3d.com/product/nozzle-0-4/">an alternative 0.4mm nozzle</a> compatible with i3 and MINI/+ printers.</div>
<h3>Tools necessary</h3>
<ul>
<li>2.5 mm Allen key (Included with assembled printers and kits)</li>
<li>7 mm spanner/socket or pliers (7 mm spanner/socket not included with assembled printers and kits)</li>
<li>17 mm spanner (not included with assembled printers and kits)</li>
<li>Small plate or aluminium foil (not included with assembled printers and kits)</li>
</ul>
<h3>Procedure</h3>
<p>The following procedure assumes that a firmware version from 3.12.0 or above is installed. In case your printer has a previous firmware version, we recommend <a href="http://help.prusa3d.com/article/how-to-update-firmware-mk3s-mk3s-mk3_2227">upgrading to the latest version</a>. If you did not flash a newer firmware version, follow the procedure, except for "Step 3 alternative" instead of step 3.</p>
<div class="note-callout"><strong>Follow this procedure exactly!</strong> Omitting steps can cause leaking and extrusion issues outlined at the end of this article.</div>
<ol start="1">
<li>Unload the filament, if it is loaded, from <em>LCD Menu -&gt; Unload Filament</em>. Optionally, perform a <a href="http://help.prusa3d.com/article/cold-pull-mk3-s-mk2-5-s-mk3-5-s_2075">Cold pull (MK3/S/+, MK2.5/S, MK3.5/S)</a>.</li>
<li>On <strong>MK2.5/S</strong> and <strong>MK3/S/+</strong>, navigate to <em>LCD Menu -&gt; Settings -&gt; HW Setup -&gt; Nozzle Change</em>.
<ol type="a">
<li>The printer will display a message with a link to this guide.</li>
<li><strong>Click the LCD encoder</strong>: the printer will auto-home, and subsequently move the Z axis to the topmost position, and the X axis to the center. In the meantime, the printer will automatically heat the nozzle to <strong>280 °C</strong>. Heating the nozzle is essential for this process.</li>
<li>Once the nozzle is at <strong>280 °C</strong>, the printer screen will display the following message: "<strong>Hotend at 280C! Nozzle changed and tightened to specs?</strong>". Do not click on the LCD encoder for now. 
<p>On <strong>MK3.5/S</strong>, gain better access to the nozzle by moving the extruder as high as possible, go to <em>LCD Menu -&gt; Control -&gt; Move Axis -&gt; Move Z</em>. Spin the <strong>Knob</strong> to adjust the height. Once this is done, preheat the nozzle to 280 °C from <em>LCD Menu -&gt; Control -&gt; Temperature -&gt; Nozzle Temperature</em>. </li>
</ol>
</li>
</ol>
<div class="warning-callout">CAUTION: Heated parts can cause severe burns!</div>
<ol start="3">
<li>Unscrew the two screws on the print fan and the single screw securing the fan shroud. Remove both parts (picture below).</li>
</ol>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/06/85adeda53781f1c8b8e5ad32a6c8d6c6.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Changing or replacing the nozzle (MK2.5S/MK3S/MK3S+) review" alt="" width="600" height="403" loading="lazy" /></p>
<ol start="4">
<li>Hold the heater block with a 17 mm spanner (M10) or adjustable wrench.</li>
</ol>
<div class="warning-callout">Be extra careful around the <strong>fragile</strong> hotend heater and thermistor wires. You can break them off or <strong>short-circuit the heater with your spanner!</strong></div>
<ol start="5">
<li>Unscrew the nozzle using the supplied pliers. If you are using the E3D nozzles from our online store, use a 7mm spanner (M4) or 7 mm socket. <strong>Be careful, the nozzle is still hot! Place it out of the way on your non-flammable surface.</strong></li>
<li>Make sure that the printer is still on the screen described in step 3c, and that the set temperature (280 °C) didn't change. Holding the heater block with your spanner, carefully screw the new nozzle in and tighten it gently, but firmly. <strong>Do not use excessive force!</strong></li>
</ol>
<div class="tip-callout">Our service and assembly teams use a torque wrench rated for 1 - 5 N m and <strong>tighten the nozzle with a force of 2.5 N m</strong> (Newton Meter).</div>
<h3>Final inspection</h3>
<p><strong>There must always be a gap (~0.5 mm)</strong> between the nozzle and the heater block (left picture). The nozzle must be tightened/secured in the heater block, and <strong>locked against the heat break</strong> while heated (right picture). Failing to do so will cause leaks (center picture).</p>
<div class="warning-callout"><strong>It is necessary to redo the <a href="http://help.prusa3d.com/article/first-layer-calibration-i3_112364">First Layer Calibration (i3)</a> after replacing the nozzle.</strong> If you installed a nozzle with a diameter other than 0.4 mm (0.25, 0.6, 0.8 mm), please see <a href="http://help.prusa3d.com/article/different-nozzle-types_2193#first-layer-calibration-of-other-nozzles">Different nozzle types</a>.</div>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 39.2947%;"><img decoding="async" style="float: left;" src="https://cdn.help.prusa3d.com/wp-content/uploads/ljZASfpEuJDMIZZo_8643_painted.jpeg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/ljZASfpEuJDMIZZo_8643_painted-300x300.jpeg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/ljZASfpEuJDMIZZo_8643_painted-400x400.jpeg 400w" alt="" width="300" height="300" loading="lazy" /></td>
<td style="width: 60.7053%;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/526a59ae1e9dcd1b_painted.png" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/526a59ae1e9dcd1b_painted-300x136.png 300w, https://cdn.help.prusa3d.com/wp-content/uploads/526a59ae1e9dcd1b_painted-600x272.png 600w, https://cdn.help.prusa3d.com/wp-content/uploads/526a59ae1e9dcd1b_painted-768x348.png 768w, https://cdn.help.prusa3d.com/wp-content/uploads/526a59ae1e9dcd1b_painted-800x363.png 800w" alt="" width="772" height="350" loading="lazy" /></td>
</tr>
</tbody>
</table>
<div class="tip-callout">You can find this procedure as <a href="https://youtu.be/txt6sxV6X88">a video on our YouTube channel</a>. Be aware that some steps may differ slightly from the procedure outlined here, and printed parts of the extruder may look a little different than yours.</div>


Changing or replacing the nozzle (MK2.5/S, MK3/S/+, MK3.5/S)

<p></p>
<p>A 'cold pull' is a technique that allows you to clean your printer’s nozzle and hotend from any material that may be stuck or burnt inside. You can also use it to clean your hotend during your usual maintenance routine.</p>
<div class="warning-callout">If you are using Nozzle X, <strong>do not</strong> use the cold-pull method, but only use cleaning filament.</div>
<p>The cold pull should be made if your nozzle is only partially clogged, and some filament is still being extruded. If the nozzle is completely clogged, please check the <a href="http://help.prusa3d.com/article/clogged-nozzle-hotend-mk3-5-s-mk3s-mk2-5s_2008">Clogged nozzle guide</a>.</p>
<div class="tip-callout">Our testing has found that <strong>PLA works best for a cold pull,</strong> as other filaments do not retain the tip as PLA does and they will either tear or melt too much. However, there are filaments specifically made for cleaning hotends.</div>
<h3>Procedure</h3>
<ol>
<li>Go to the <em>LCD Menu -&gt; Settings -&gt; Temperature -&gt; Nozzle</em> (MK2.5/S, MK3/S/+) / <em>LCD Menu -&gt; Control -&gt; Temperature -&gt; Nozzle </em>(MK3.5/S), and set the temperature to 270 °C.</li>
<li>While waiting for the nozzle to reach the temperature, toggle the <strong>Filament autoload</strong> off in the <em>LCD Menu -&gt; Settings -&gt; Fil. sensor -&gt; F. autoload </em>(MK2.5/S, MK3/S/+) / <em>LCD Menu -&gt; Settings -&gt; Filament sensor </em>(MK3.5/S).</li>
<li>Still being in the <em>Menu</em>, go to <em>Settings</em> and choose <em>Disable steppers </em>(MK2.5/S, MK3/S/+). On MK3.5/S, navigate to <em>Control -&gt; Disable motors</em>. <br /><em>There is no message of the steppers being disabled, but you may hear an electrical hiss disappear when selected. <strong>If you can move the bed or extruder on its axis by hand, they are disabled.</strong></em></li>
<li>Open the Extruder Idler door. <em>Unscrew the screws circled below using a 2.5 mm Allen key. On the MMU2S and MMU3, unscrew the Bowden PTFE tube that connects the MMU unit with the extruder.</em></li>
</ol>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.805%;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/idler2.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/idler2-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/idler2-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/idler2-768x768.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/idler2-600x600.jpg 600w" alt="" width="400" height="399" loading="lazy" /></td>
<td style="width: 48.9057%;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/mmus2.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/mmus2-300x216.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/mmus2-554x400.jpg 554w, https://cdn.help.prusa3d.com/wp-content/uploads/mmus2-768x554.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/mmus2-800x577.jpg 800w" alt="mmu" width="400" height="290" loading="lazy" /></td>
</tr>
</tbody>
</table>
<ol start="5">
<li>Once it has reached 270 °C, insert PLA filament manually into the extruder and push it in until it starts pouring out of the nozzle.</li>
<li>Stop heating by pressing <em>Cooldown</em> in the <em>LCD Menu -&gt; Preheat</em> (scroll all the way down), or by pressing the reset (X) button. Let the nozzle temperature drop to room temperature. To speed up the cooling you can engage the print fan at full speed, from<em> LCD menu -&gt; Settings/Control -&gt; Temperatures -&gt; Fan speed -&gt; [255].</em></li>
<li>Continue manually pushing the filament down until the temperature is too low for it to melt and come out (around 170 °C for PLA). <em>The nozzle has to be filled for the cold pull to be successful.</em></li>
<li>Pick away extruded material so there is nothing obstructing the pull later on.</li>
<li>After the nozzle cools down to the room temperature, go again to the <em>LCD Menu -&gt; Settings/Control -&gt; Temperature -&gt; Nozzle</em> and set the temperature to 85 °C.</li>
<li><strong>As soon as the extruder reaches this temperature</strong>, grab the filament with pliers and pull it slowly but steadily out of the extruder. <em>The filament can break inside. Make sure to pull straight upwards, not sideways. Hold the extruder with your other hand.</em></li>
<li>Don't stop until the filament is completely pulled out from the extruder.</li>
</ol>
<h3>Results</h3>
<p>On the tip of the filament that has been pulled out, you may see remnants of the previous material(s) you have been using or some burnt dirt that has settled in the nozzle (left picture). You might want to repeat this procedure several times until the filament comes out clean.</p>
<p>The right picture shows what a clean cold-pulled filament should look like. It is important to have the imprint of the nozzle on it, this way you are sure the nozzle was filled and nothing was left inside. Also, the color is not mixed with the one you have been using previously or have dark marks on it.</p>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.805%;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/dirty-cold-pull.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/dirty-cold-pull-300x214.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/dirty-cold-pull-561x400.jpg 561w, https://cdn.help.prusa3d.com/wp-content/uploads/dirty-cold-pull-768x548.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/dirty-cold-pull-800x571.jpg 800w" alt="dirty cold pull" width="400" height="286" loading="lazy" /></td>
<td style="width: 48.9057%;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/clean-cold-pull.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/clean-cold-pull-300x203.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/clean-cold-pull-591x400.jpg 591w, https://cdn.help.prusa3d.com/wp-content/uploads/clean-cold-pull-768x520.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/clean-cold-pull-800x542.jpg 800w" alt="clean cold pull" width="693" height="469" loading="lazy" /></td>
</tr>
</tbody>
</table>
<h3>After the procedure</h3>
<p>Secure the idler door by having <strong>the head of the idler screw</strong>, on the left of the extruder, <strong>about flush with the plastic parts, when the filament is not loaded.</strong> Then we recommend running the Z calibration as pushing on the extruder might have thrown it off balance. Also, turn the filament sensor/filament autoload back on.<br />On MK2.5/S and MK3/S/+, the Z-axis calibration is found in <em>LCD menu -&gt; Calibration -&gt; Calibrate Z</em>).<br />On MK3.5/S, the Z-axis calibration is found in <em>LCD menu -&gt; Control -&gt; Calibrations &amp; tests -&gt; 3. Z alignment calibration</em>.</p>
<div class="note-callout">Please see <a href="http://help.prusa3d.com/article/under-extrusion_2007">this article</a> to learn about the most common causes leading to filament extrusion problems and how to prevent them from happening.</div>

Cold pull (MK3/S/+, MK2.5/S, MK3.5/S)

<p>On printers with the xLCD with a USB drive connector, the firmware is flashed using a USB flash drive.</p>
<ol>
<li>Download the latest firmware for your printer and extract it (zip file) on your computer
<ul>
<li><a href="https://help.prusa3d.com/tag/mk4s">Original Prusa MK4S</a></li>
<li><a href="https://help.prusa3d.com/tag/mk4">Original Prusa MK4</a></li>
<li><a href="https://help.prusa3d.com/tag/mk3-9s">Original Prusa MK3.9S</a></li>
<li><a href="https://help.prusa3d.com/tag/mk3-9">Original Prusa MK3.9</a></li>
<li><a href="https://help.prusa3d.com/tag/mk3-5s">Original Prusa MK3.5S</a></li>
<li><a href="https://help.prusa3d.com/tag/mk3-5">Original Prusa MK3.5</a></li>
<li><a href="https://help.prusa3d.com/tag/xl">Original Prusa XL</a></li>
</ul>
</li>
<li>Make sure the USB flash drive doesn't contain any previous firmware (.bbf file)</li>
<li>Copy the new .bbf file to the root directory of a USB flash drive (Not within a folder).</li>
<li>Insert the USB flash drive and push the reset button<strong>.</strong> The bootloader will automatically compare the installed version with the one on the drive and, if newer, will automatically offer you to flash it.</li>
<li>Confirm the update by selecting the "FLASH" button and pressing the knob. </li>
</ol>
<p>If you need to downgrade the firmware or re-flash the same firmware, follow this guide: <a href="http://help.prusa3d.com/article/how-to-downgrade-firmware-mk4-s-mk3-9-s-mk3-5-s-xl_725930">How to downgrade firmware</a>.</p>
<div><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2023/05/035427dd374ce9f494d89568ff3e72ac.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Flashing firmware (MK4)" alt="" width="700" height="276" loading="lazy" /></div>
<h3>Factory Reset</h3>
<p>If you do a hard <a href="http://help.prusa3d.com/article/factory-reset-mk4-s-mk3-9-s-mk3-5-s-mini-xl_421206">Factory Reset</a>, the firmware that is in the USB will also be installed in the printer, so this can be used as a way to update the firmware.</p>


How to update firmware (MK4/S, MK3.9/S, MK3.5/S, XL)

<p>In case there is a clog in your hotend, the filament might grind against the Bondtech-gears and be damaged enough so it can't be unloaded. It might snap right above the PTFE-tube when you try to pull it out by hand. In this case, the filament will need to be removed manually.</p>
<h3>Idler door open</h3>
<p>Open the idler door by removing the spring-loaded tension-screw(s), on the left side of the extruder.</p>
<table style="border-collapse: collapse; width: 100%; height: 348px;" border="0">
<tbody>
<tr style="height: 331px;">
<td style="width: 50%; height: 331px;"><img decoding="async" style="max-height: 350px; display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/4aheOXhkPQx2kAAu.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/4aheOXhkPQx2kAAu-300x225.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/4aheOXhkPQx2kAAu-533x400.jpg 533w, https://cdn.help.prusa3d.com/wp-content/uploads/4aheOXhkPQx2kAAu-768x576.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/4aheOXhkPQx2kAAu-800x600.jpg 800w" width="400" height="300" loading="lazy" data-hd-height="350px" data-hd-align="center" /></td>
<td style="width: 50%; height: 331px;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/MK3.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/MK3-300x225.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/MK3-534x400.jpg 534w" alt="" width="400" height="300" loading="lazy" /></td>
</tr>
<tr style="height: 17px;">
<td style="width: 50%; height: 17px; text-align: center;"><strong>MK3S, MK3S+, MK3.5/S extruder (single idler screw)</strong></td>
<td style="width: 50%; height: 17px; text-align: center;"><strong>MK3 extruder (two idler screws)</strong></td>
</tr>
</tbody>
</table>
<div> </div>
<h4>MMU2S/MMU3 idler door</h4>
<div>On the MMU, due to the "chimney" (IR-sensor-holder-mmu2s), you must remove the whole idler door by unscrewing the hinge- screw (red arrow) on the back. </div>
<div> </div>
<div><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/idlermmu2s.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/idlermmu2s-300x225.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/idlermmu2s-533x400.jpg 533w, https://cdn.help.prusa3d.com/wp-content/uploads/idlermmu2s-768x576.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/idlermmu2s-800x600.jpg 800w" alt="" width="401" height="301" loading="lazy" /></div>
<h3>Where did it break?</h3>
<table style="border-collapse: collapse; width: 100%; height: 311px;" border="0">
<tbody>
<tr style="height: 294px;">
<td style="width: 50%; height: 294px;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0300.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0300-300x225.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0300-533x400.jpg 533w, https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0300-768x576.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0300-800x600.jpg 800w" alt="" width="400" height="300" loading="lazy" /></td>
<td style="width: 50%; height: 294px;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0271.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0271-300x225.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0271-533x400.jpg 533w, https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0271-768x576.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0271-800x600.jpg 800w" alt="" width="399" height="299" loading="lazy" /></td>
</tr>
<tr style="height: 17px;">
<td style="width: 50%; height: 17px; text-align: center;"><strong>Use Method 1</strong></td>
<td style="width: 50%; text-align: center; height: 17px;"><strong>Use Method 2</strong></td>
</tr>
</tbody>
</table>
<p>If the filament snapped right at the edge of the PTFE you should start with Method number 1, where you try to push the filament through the hotend. If there is 0.5-1cm sticking out of the filament, reaching the Bondtech filament-pulley starts with Method number 2, pulling it out with pliers.</p>
<h3>Setup</h3>
<ol>
<li>Go to the <em>LCD Menu -&gt; Settings -&gt; Temperature -&gt; Nozzle</em> and set the temperature to 280º C. Wait for 3-5 minutes with the hotend at this temperature.</li>
<li>In the LCD menu in <em>Settings,</em> select <em>Disable steppers</em>.</li>
<li>Go to the  <em>LCD Menu -&gt; Settings -&gt; F. Autoload,</em> so A<em>utoload</em> will not interfere.</li>
</ol>
<div class="warning-callout">From now on the hotend will be hot! Avoid touching the lower part of the extruder (heaterblock + nozzle)!</div>
<h3>Method 1: Pushing the filament through the hotend</h3>
<p>Using another piece of filament, a thin (1-1,5 mm) Allen-wrench or same diameter wire, at least 4.5 cm long for the MK3(s) and 6 cm long for the MMU2s, you are often able to simply push it through.</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0270scales.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0270scales-300x225.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0270scales-533x400.jpg 533w, https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0270scales-768x576.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0270scales-800x600.jpg 800w" alt="" width="574" height="431" loading="lazy" /></p>
<p> </p>
<ol>
<li>Feed in from the top of the extruder your tool of choice, down past the Bondtech-gear, and on top of the stuck filament.</li>
</ol>
<div class="note-callout">If you are able to push the stuck filament down the PTFE-tube with an Allen-wrench, switch to using filament after about 1-2 cm. Some Allen-wrenches may only be long enough to get it started.</div>
<ol start="2">
<li>In case the filament starts being extruded from the bottom, Keep pushing the filament to clear the nozzle and see the color change.</li>
</ol>
<h3>Method 2: Pull out filament with pliers</h3>
<p>While hotend is heated to 280° C, firmly grab the filament with the needle-nose pliers that came with the printer. Slowly drag/feed the filament upwards, bit by bit, through the top of the extruder body, until it is completely removed from the PTFE-tube.</p>
<p>The filament can get stuck on geometry on the path up through where it is fed. It is also possible to pull it out of the idler door.</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0275.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0275-300x225.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0275-533x400.jpg 533w, https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0275-768x576.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/DSC_0275-800x600.jpg 800w" alt="" width="627" height="470" loading="lazy" /></p>
<p> </p>
<div class="tip-callout">After removing the filament, do a <a href="http://help.prusa3d.com/article/cold-pull-mk3-s-mk2-5-s-mk3-5-s_2075">Cold pull (MK3/S/+, MK2.5/S, MK3.5/S)</a> to ensure you have fully cleared the clog.</div>
<h3>Nope, it is still stuck</h3>
<p>If none of these methods work, it means that the tip is not touching the part of the hotend that is heated and is stuck in the PTFE-tube. In this case, you must extract the PTFE-tube. Follow the guide linked below to resolve it.</p>
<div class="note-callout">You will probably need to heat the hotend to extract the PTFE-tube with the stuck filament.</div>
<ul>
<li><a href="http://help.prusa3d.com/guide/how-to-replace-a-ptfe-tube-mk3-mk2-5_17360">How to replace a PTFE tube (MK3/MK2.5)</a></li>
<li><a href="http://help.prusa3d.com/guide/how-to-replace-a-hotend-ptfe-tube-mk3s-mk3s-mk2-5s-mmu2s_21664">How to replace a hotend PTFE tube (MK3S+/MK3S/MK2.5S/MMU2S)</a></li>
</ul>


Removing filament from extruder manually

<p>As there are ways of remotely transferring files and starting prints, an SD card or USB flash drive is the most common and reliable way to get your files to your machine. Though common and convenient, flash memory is not the most reliable in itself and your storage can be corrupted or fill up without any obvious signs. Therefore, we have put together a small guide on how to maintain, format, and purchase memory for your Original Prusa printer.</p>
<h3>Make sure your SD card is not locked!</h3>
<p>The SD card has a latch on the side. Before using your SD card, make sure that the latch is not set to the Locked position. In case it is locked, you will not be able to save files on the card, and the printer will not be able to open the SD card.</p>
<p><img decoding="async" style="max-height: 350px; display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/SD-cards-and-USB-flash-drives-01.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/SD-cards-and-USB-flash-drives-01-300x293.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/SD-cards-and-USB-flash-drives-01-410x400.jpg 410w" data-hd-height="350px" data-hd-align="center"></p>
<h3>Storage over 32 GB</h3>
<p>There is no upper size limit on compatible storage media, but <strong>the built-in Windows formatting tool does not support formatting storage media from a size of 32 GB or more to FAT32.</strong> It will only provide the option for exFAT, which is currently not supported by our printers. There are similar limitations under various versions of Apple's OSx, where a third-party application must be used to format it correctly.</p>
<p>To format such a drive you need a third-party application, like Rufus, FAT32 format, or EaseUS Partition Master. <strong>Be careful when using such programs</strong> so you do not <strong>accidentally format the wrong storage media</strong>, like your hard drive. However, 8-16 GB is more than enough for most use cases, as a G-code file rarely exceeds 100 MB.</p>
<h3>How do I format the USB drive/SD card?</h3>
<p>If your SD card or USB drive is full or if you can't read the content of the drive, but the drive is recognized by windows, most often all you need to do is to format the drive.</p>
<div class="note-callout">If your USB drive or SD card does not even show up in your computer file explorer it is probably corrupted beyond repair, or at least beyond the scale of this article. If you get an error like the one in the picture below and it does not show up anywhere, off to google you go, but you might have to consider this card/USB drive lost and get a new one.</div>
<p><img decoding="async" loading="lazy" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/SD-cards-and-USB-flash-drives-02V3.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/SD-cards-and-USB-flash-drives-02V3-600x238.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/SD-cards-and-USB-flash-drives-02V3-800x317.jpg 800w, https://cdn.help.prusa3d.com/wp-content/uploads/SD-cards-and-USB-flash-drives-02V3-300x119.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/SD-cards-and-USB-flash-drives-02V3-768x304.jpg 768w" alt="" width="631" height="250"></p>
<h3>How to format on Windows</h3>
<p>On Windows, this is very simple. Locate your USB drive or SD card in my computer, right-click, and choose format.</p>
<p><img decoding="async" style="max-height: 350px; display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/SD-cards-and-USB-flash-drives-03.png" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/SD-cards-and-USB-flash-drives-03-300x288.png 300w, https://cdn.help.prusa3d.com/wp-content/uploads/SD-cards-and-USB-flash-drives-03-417x400.png 417w, https://cdn.help.prusa3d.com/wp-content/uploads/SD-cards-and-USB-flash-drives-03-768x737.png 768w, https://cdn.help.prusa3d.com/wp-content/uploads/SD-cards-and-USB-flash-drives-03-625x600.png 625w" data-hd-height="350px" data-hd-align="center"></p>
<p>A new small window will pop up. Most of the time you can simply leave everything to default, but the most important thing is that the <strong>File System is set to FAT32.</strong> This and the Volume Label (Name of the drive) is the only thing you want to touch here. Click Start and your drive will be formatted in a matter of seconds.</p>
<div class="warning-callout">Formatting any drive will delete all the content of the drive! Back up your stuff!</div>
<p><img decoding="async" style="max-height: 300px; display: block; margin-left: auto; margin-right: auto;" title="https://cdn.help.prusa3d.com/wp-content/uploads/SD-cards-and-USB-flash-drives-04-166x300.png 166w, https://cdn.help.prusa3d.com/wp-content/uploads/SD-cards-and-USB-flash-drives-04-222x400.png 222w" src="https://cdn.help.prusa3d.com/wp-content/uploads/SD-cards-and-USB-flash-drives-04.png" data-hd-height="300px" data-hd-align="center"></p>
<div class="note-callout">If the USB stick will not work even after this procedure, it is either broken or its "partitioning scheme" is set as GPT, which is incorrect. <strong>It must be set as MBR (Master Boot Record).</strong> For how to change this, please see <a href="https://docs.microsoft.com/en-us/windows-server/storage/disk-management/change-a-gpt-disk-into-an-mbr-disk">Microsoft's official documentation</a>.</div>
<h3>How to format on Mac</h3>
<p>On Mac, it is a few more steps, but still very accessible. Again, you want to choose <strong>FAT32 as your file system</strong>, but you also have the option of changing the "partitioning scheme", which <strong>should always be MBR (Master Boot Record).</strong></p>
<div class="warning-callout">This process deletes all content from the drive.</div>
<ol>
<li>Plug the USB drive or SD card into your Mac.</li>
<li>Go to <em>Applications -&gt; Utilities</em> and launch <em>Disk Utility.</em></li>
<li>Click on the icon in the top-left (<span style="color: #2dc26b;">green arrow</span>) and select "Show All Devices" from the drop-down menu.</li>
</ol>
<p><img decoding="async" loading="lazy" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/b49c3bac01f2fd71_painted.png" sizes="(min-width: 1024px) 820px, 100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/b49c3bac01f2fd71_painted-600x271.png 600w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/b49c3bac01f2fd71_painted-800x361.png 800w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/b49c3bac01f2fd71_painted-300x135.png 300w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/b49c3bac01f2fd71_painted-768x347.png 768w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/b49c3bac01f2fd71_painted-1536x693.png 1536w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/b49c3bac01f2fd71_painted.png 1600w" alt="" width="500" height="226"></p>
<p style="text-align: center;"><em>macOS Big Sur 11.6</em></p>
<ol start="4">
<li>Right-click on the USB drive/SD card in the sidebar under "External". <em>Select the top entry for your drive, not a partition located below.</em></li>
<li>Select Erase in the Disk Utility-toolbar (<span style="color: #b96ad9;">purple arrow</span>).</li>
</ol>
<p><img decoding="async" loading="lazy" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/b04f0e7375dfbc17_painted.png" sizes="(min-width: 1024px) 820px, 100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/b04f0e7375dfbc17_painted-600x271.png 600w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/b04f0e7375dfbc17_painted-800x361.png 800w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/b04f0e7375dfbc17_painted-300x135.png 300w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/b04f0e7375dfbc17_painted-768x347.png 768w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/b04f0e7375dfbc17_painted-1536x693.png 1536w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/b04f0e7375dfbc17_painted.png 1600w" alt="" width="500" height="226"></p>
<p style="text-align: center;"><em>macOS Big Sur 11.6</em></p>
<ol start="6">
<li>Enter a name for the formatted disk.</li>
<li>Click on the Format menu and choose MS-DOS (FAT).</li>
<li>Make sure the Scheme is set to "Master Boot Record".</li>
</ol>
<p><img decoding="async" loading="lazy" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/snmek-obrazovky-2021-10-07-v8-32-01.png" sizes="(min-width: 1024px) 820px, 100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/snmek-obrazovky-2021-10-07-v8-32-01-600x301.png 600w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/snmek-obrazovky-2021-10-07-v8-32-01-800x401.png 800w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/snmek-obrazovky-2021-10-07-v8-32-01-300x150.png 300w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/snmek-obrazovky-2021-10-07-v8-32-01-768x385.png 768w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/snmek-obrazovky-2021-10-07-v8-32-01-1536x771.png 1536w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/snmek-obrazovky-2021-10-07-v8-32-01-2048x1027.png 2048w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/10/snmek-obrazovky-2021-10-07-v8-32-01.png 1600w" alt="" width="500" height="251"></p>
<p style="text-align: center;"><em>macOS Big Sur 11.6</em></p>
<ol start="9">
<li>Click Erase.</li>
<li>Your USB drive will now be erased and re-formatted correctly.</li>
</ol>
<div class="tip-callout">If your SD card is not detected by the printer at all, be sure to check out <a href="http://help.prusa3d.com/article/sd-card-not-working_2095">SD card not working</a> for further information.</div>

SD cards and USB drives

<p>The Bondtech gears have a lot of pulling force. They might seem secure, but unless properly tightened, <strong>on the flat side of the motor's shaft,</strong> they can come loose and remain stationary around the spinning shaft. This might only be intermittent at first, acting like under extrusion, but the gear will continue to loosen and/or slide out of alignment with the filament path.</p>
<h3>Typical issue (false clog)</h3>
<p>This might appear as a clog at first, but you can see the motor axle rotating fully, and there is no clicking sound, which is common during a hotend clog. The filament is not moving at all and when pulled out, it does not look like it has been ground by the gear, hence the name "false or ghost clog".</p>
<p style="text-align: center;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/Extrdueer-motor72dpi.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/Extrdueer-motor72dpi-300x265.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/Extrdueer-motor72dpi-453x400.jpg 453w, https://cdn.help.prusa3d.com/wp-content/uploads/Extrdueer-motor72dpi-768x678.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/Extrdueer-motor72dpi-680x600.jpg 680w" alt="" width="451" height="398" loading="lazy" /></p>
<div class="tip-callout" style="text-align: center;">It can be helpful to draw a line on the radius of the axle, to see if it spins or not.</div>
<h3>Accessing the Bondtech gear</h3>
<p>Start by getting out your 1,5 mm and 2.5 mm Allen keys. Using the 2.5 mm Allen key, release the spring-tensioned idler-screw(s) completely and open the idler door. It is 1 on the Original Prusa MK3S &amp; MK3S+ (left picture) and two on the Original Prusa MK3 (right picture). The MMU2S extruder has one screw, but some additional parts.</p>
<table style="border-collapse: collapse; width: 99.7482%; height: 376px;" border="0">
<tbody>
<tr style="height: 454px;">
<td style="width: 33.3333%; height: 358px; vertical-align: bottom;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/4aheOXhkPQx2kAAu.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/4aheOXhkPQx2kAAu-300x225.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/4aheOXhkPQx2kAAu-533x400.jpg 533w, https://cdn.help.prusa3d.com/wp-content/uploads/4aheOXhkPQx2kAAu-768x576.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/4aheOXhkPQx2kAAu-800x600.jpg 800w" alt="" width="533" height="400" loading="lazy" /></td>
<td style="width: 33.3333%; height: 358px; vertical-align: bottom;"><em><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/MK3.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/MK3-300x225.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/MK3-534x400.jpg 534w" alt="" width="533" height="400" loading="lazy" /></em></td>
</tr>
<tr style="height: 18px;">
<td style="width: 33.3333%; height: 18px; text-align: center;"><em>Original Prusa MK3S &amp; MK3S+ / MK3.5</em></td>
<td style="width: 33.3333%; height: 18px; text-align: center;"><em>Original Prusa MK3 (Non S/+-upgrade)</em></td>
</tr>
</tbody>
</table>
<table style="border-collapse: collapse; width: 100%; height: 436px;" border="0">
<tbody>
<tr style="height: 400px;">
<td style="width: 100%; text-align: center; height: 400px;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/idlermmu2s.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/idlermmu2s-300x225.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/idlermmu2s-533x400.jpg 533w, https://cdn.help.prusa3d.com/wp-content/uploads/idlermmu2s-768x576.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/idlermmu2s-800x600.jpg 800w" alt="" width="533" height="400" loading="lazy" /></td>
</tr>
<tr style="height: 36px;">
<td style="width: 100%; height: 36px;">
<p> <strong>On the Original Prusa MMU2S / MMU3, you must remove the whole idler door (<span style="color: #3598db;">blue arrows</span>), by removing</strong></p>
<p style="text-align: center;"><strong>the screw acting as its hinge (<span style="color: #e03e2d;">red arrow</span>).</strong></p>
</td>
</tr>
</tbody>
</table>
<div class="tip-callout">On the Original Prusa MK3S, <a href="http://help.prusa3d.com/guide/5-e-axis-assembly_28536#30456">remove the single screw on the top of the extruder</a> to remove the fil. sensor cover to open the idler door all the way.</div>
<h3>Rotating the motor's shaft</h3>
<p>You will now have access to the Bondtech gears. With the idler door open, we will check if the Bondtech gear is secured on the <strong>flat side of the motor shaft and if the gear is out of alignment with the filament path.</strong> We do not recommend moving the motor shaft by hand. The best is to start rotation from the LCD menu:</p>
<ul>
<li>Preheat the nozzle from the <em>LCD-menu -&gt; Setting -&gt; Temperatures -&gt; Nozzle -&gt; 180 °C.</em> The firmware will not let you manually move the extruder motor unless heated to at least 175 °C.</li>
</ul>
<div class="warning-callout"><strong>The nozzle is now hot!</strong> Be careful so you do not burn yourself.</div>
<ul>
<li>Navigate the LCD menu to <em>Settings -&gt; Move axis -&gt; Extruder</em>, and you can now spin the extruder motor, with the knob on the LCD panel. </li>
</ul>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/bondtechallign.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/bondtechallign-300x290.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/bondtechallign-413x400.jpg 413w, https://cdn.help.prusa3d.com/wp-content/uploads/bondtechallign-768x743.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/bondtechallign-620x600.jpg 620w" alt="" width="465" height="450" loading="lazy" /></p>
<p>Make sure the flat side of the motor shaft is visible (<span style="color: #e03e2d;"><strong>red lines</strong></span>), aligned with the black set-screw on the pulley (<span style="color: #b96ad9;"><strong>purple arrow</strong></span>), and that pulley grooves are aligned with the filament (<span style="color: #2dc26b;"><strong>green line</strong></span>).</p>
<div class="warning-callout">The set-screw may be stuck due to rust or Loctite. If you have to use a lot of force you may risk stripping the head of the screw. Consult with our <a href="http://help.prusa3d.com/article/customer-support_2287">technical support</a> before you use excessive force.</div>
<p>You can use a piece of filament, inserted from the top (<span style="color: #3598db;"><strong>blue arrow</strong>)</span>, to check alignment. Then use the 1.5 mm Allen wrench or your nail to move the Bondtech gear into position, before securing the set screw.</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/aa928d37bf9ddb9e_painted.jpeg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/aa928d37bf9ddb9e_painted-400x400.jpeg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/aa928d37bf9ddb9e_painted-600x600.jpeg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/aa928d37bf9ddb9e_painted-300x300.jpeg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/aa928d37bf9ddb9e_painted-768x768.jpeg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/aa928d37bf9ddb9e_painted-1536x1536.jpeg 1536w" alt="" width="450" height="450" loading="lazy" /></p>
<h3>Clean Bondtech gear</h3>
<p>Open the Extruder idler. You can see how to do it in our assembly manuals, section <a href="http://help.prusa3d.com/guide/5-e-axis-assembly_28536#29848">Extruder idler parts preparation</a>, in the E-axis assembly chapter. Clear any left-over filament, rust, or dust with a brush and inspect both gears.</p>
<p>It is recommended to use a <a href="https://www.prusa3d.com/product/prusa-lubricant-applicator-set-5g/">Prusa Lubricant</a> or a PTFE-based grease. However, be careful not to overuse it, as it tends to accumulate dust particles over time. This procedure should be done roughly every 3-6 months, depending on how often you are using the printer.</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2022/10/cleaning-Bondtech-gear.jpg" alt="" width="600" height="267" loading="lazy" /></p>
<p>Put the lubricant on the Bondtech extruder gear teeth. <strong>Apply it only to the toothed part</strong> as seen in the right photo above. If you apply it to the whole gear, it will be unable to grab filament properly!</p>
<p>You can also inspect the needle bearings that are inside and clean them with a brush. However, these do not need any special care, just make sure that both of them are properly inserted.</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2022/10/Bondtech-need-bearings.jpg" alt="" width="400" height="174" loading="lazy" /></p>

Checking/re-aligning the Bondtech gear (MK3.5/S, MK3S/+, MK2.5S)

<p>Before you start printing, you should know that various materials have different adhesions on various surfaces. It is crucial to pick the right steel sheet for your printer and prepare its surface properly. This article is about the most common types of print surfaces and how to prepare them for printing.</p>
<div class="tip-callout">To kick it off with a quick (and most common) example: PETG filament has great adhesion to a clean, degreased, smooth PEI sheet, making it extremely hard to remove. Removing the print often leads to peeling off the PEI surface and irreversible damage to the sheet. This is why we recommend using another type of steel sheet or adding PVA glue as a separation layer on the print surface.</div>
<h3><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/steelsheet.jpg" alt="" width="1024" height="703" loading="lazy" /></h3>
<p><em>Steel sheet damaged by a PETG print</em></p>
<h3>Choosing the right print sheet</h3>
<p>We offer 4 types of spring steel sheets, each has a different surface finish that leaves not only a specific texture on your print but also supports a variety of materials that can be printed on it.</p>
<div class="note-callout"><a href="http://help.prusa3d.com/article/smooth-steel-sheet_196550">Here’s a guidepost</a> that provides the most information about the maintenance and properties of our three most common print sheets. Plus, <a href="http://help.prusa3d.com/article/special-pa-nylon-steel-sheet_341570">here’s an article</a> about our special PA Nylon steel sheet.</div>
<table style="border-collapse: collapse; width: 100%; height: 36px; margin-left: auto; margin-right: auto;" border="0">
<tbody>
<tr style="height: 18px;">
<td style="width: 32.2013%; height: 18px;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2020/12/spring-steel-sheet-smooth-peiKB.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/2020/12/spring-steel-sheet-smooth-peiKB-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/2020/12/spring-steel-sheet-smooth-peiKB-600x600.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/2020/12/spring-steel-sheet-smooth-peiKB-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/2020/12/spring-steel-sheet-smooth-peiKB-768x768.jpg 768w" alt="" width="266" height="266" loading="lazy" /></td>
<td style="width: 32.2013%; height: 18px;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2020/12/powder-coated-spring-steel-sheetKB.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/2020/12/powder-coated-spring-steel-sheetKB-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/2020/12/powder-coated-spring-steel-sheetKB-600x600.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/2020/12/powder-coated-spring-steel-sheetKB-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/2020/12/powder-coated-spring-steel-sheetKB-768x768.jpg 768w" alt="" width="266" height="266" loading="lazy" /></td>
<td style="width: 32.2013%; height: 18px;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2020/12/double-sided-powder-coated-satin-spring-steel-sheetKB.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/2020/12/double-sided-powder-coated-satin-spring-steel-sheetKB-400x400.jpg 400w, https://cdn.help.prusa3d.com/wp-content/uploads/2020/12/double-sided-powder-coated-satin-spring-steel-sheetKB-600x600.jpg 600w, https://cdn.help.prusa3d.com/wp-content/uploads/2020/12/double-sided-powder-coated-satin-spring-steel-sheetKB-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/2020/12/double-sided-powder-coated-satin-spring-steel-sheetKB-768x768.jpg 768w" alt="" width="266" height="266" loading="lazy" /></td>
</tr>
<tr style="height: 18px;">
<td style="width: 32.2013%; height: 18px; text-align: center;"><a href="http://help.prusa3d.com/article/smooth-steel-sheet_196550">Smooth sheet</a></td>
<td style="width: 32.2013%; height: 18px; text-align: center;"><a href="http://help.prusa3d.com/article/textured-steel-sheet_196534">Textured sheet</a></td>
<td style="width: 32.2013%; height: 18px; text-align: center;"><a href="http://help.prusa3d.com/article/satin-steel-sheet_196526">Satin sheet</a></td>
</tr>
<tr>
<td style="width: 32.2013%; text-align: center;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2021/01/Smooth_underside2.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/2021/01/Smooth_underside2-398x400.jpg 398w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/01/Smooth_underside2-598x600.jpg 598w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/01/Smooth_underside2-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/01/Smooth_underside2-768x771.jpg 768w" alt="" width="266" height="267" loading="lazy" /></td>
<td style="width: 32.2013%; text-align: center;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2021/01/TXT_underside2.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/2021/01/TXT_underside2-398x400.jpg 398w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/01/TXT_underside2-598x600.jpg 598w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/01/TXT_underside2-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/01/TXT_underside2-768x771.jpg 768w" alt="" width="266" height="267" loading="lazy" /></td>
<td style="width: 32.2013%; text-align: center;"><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2021/01/satin_underside2.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/2021/01/satin_underside2-398x400.jpg 398w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/01/satin_underside2-598x600.jpg 598w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/01/satin_underside2-300x300.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/2021/01/satin_underside2-768x771.jpg 768w" alt="" width="266" height="267" loading="lazy" /></td>
</tr>
</tbody>
</table>
<p>The best way to identify whether your sheet is suitable for the chosen material is by <a href="https://help.prusa3d.com/en/materials"><strong>checking our Material table</strong></a>. If there’s a green check mark matching the selected sheet and material, you can simply degrease the print surface and you’re good to go. If there’s an exclamation mark, a separation layer of some sort is needed (see below). <strong>Failing to use the separation layer may lead to damaging your sheet!</strong></p>
<p><img decoding="async" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/04/cbf6b670e81a869ca569857434eba048.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Print surface preparation" alt="" width="1950" height="656" loading="lazy" /></p>
<h3>Cleaning the print surface</h3>
<p>This is an easy, yet crucial step you should perform before (almost) every print. We already described this in the <a href="https://www.prusa3d.com/downloads/manual/prusa3d_manual_MK4_MK39_103_en.pdf">3D printing handbook</a> and several other places but here’s a quick reminder:</p>
<p>Grease stains (fingerprints, etc.) often cause poor surface adhesion and, eventually, a print failure. To degrease the print sheet, <strong>spray some isopropyl alcohol (90% or stronger)</strong> or denatured ethyl alcohol <strong>on the cold print surface</strong> and wipe it with an unscented paper towel. Do not use any products for skin care: they usually contain oils that ruin adhesion!</p>
<div class="note-callout">There are some more specific rules for long-term sheet maintenance and you should definitely learn these but it reaches beyond this article’s purpose. Don’t forget to go through <a href="http://help.prusa3d.com/article/smooth-steel-sheet_196550">the steel sheet guidepost</a>. Keep in mind that the <a href="http://help.prusa3d.com/article/special-pa-nylon-steel-sheet_341570">special PA Nylon sheet</a> has very different and highly specific rules for maintenance.</div>
<p>Alright, the print surface is clean, now the final checklist (<a href="https://help.prusa3d.com/en/materials">see the material table</a>):</p>
<ol>
<li><strong>Green check mark:</strong> Good to go!</li>
<li><strong>Yellow exclamation mark:</strong> Use a separation layer (see below).</li>
<li><strong>Red X:</strong> Do not print! The chosen material may damage your print sheet!</li>
</ol>
<h3>Using the most common separation layers</h3>
<p>You may find various separation (or adhesive) layer materials on the market, some of those even in our e-shop. Every material has its benefits, but describing every single one of them is beyond the scope of this article. If you check our material table, you’ll find out that it all comes down to two most common separation layers: <strong>PVA glue stick and PP tape.</strong></p>
<p><strong>PVA (paper) glue</strong> is usually sold in the form of sticks that make the application easier. <strong>Usually, only a thin layer of glue is enough.</strong> Spreading a thick layer may leave various unsightly traces, bumps, and artifacts that will be imprinted onto your 3D print’s surface. However, if you want to print a mechanical part, where good looks are not as important as functionality and reliability, making the layer slightly thicker won’t hurt. Also, the PVA glue melts at relatively low temperatures, so we suggest applying it on a cold surface to avoid making an extra thick layer.</p>
<div class="tip-callout">Tip: If you use the smooth print sheet, use the grid to guess the print size and position, then spread the glue only under the 3D print. You don’t need to spread the glue all over the whole sheet.</div>
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<td style="width: 32.2431%;"><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/04/d1bc8e9178fa20c7820b6c520c3777e0.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Print surface preparation" alt="" width="2506" height="1880" /></td>
<td style="width: 32.2431%;"><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/04/bb07c0b1d669e31b19f99420c5445ec0.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Print surface preparation" alt="" width="2506" height="1879" /></td>
<td style="width: 32.2457%;"><img decoding="async" loading="lazy" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/04/188aee6aea6ea114ef0b3a710169a3d1.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Print surface preparation" alt="" width="2506" height="1879" /></td>
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</tbody>
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<p><em>PVA glue separation layer, 3D printed PETG parts, and marks left after removing the print. Note that these marks are normal as they are only on a PVA glue layer and not on the print sheet surface. These marks disappear with the glue after washing.</em></p>
<p>Finally, <strong>the PP tape.</strong> You will most likely not use it, since it’s recommended only for printing PP (Polypropylene), which is quite rare material to print. However, you may decide to use some other tape - kapton tape, for example. For the best adhesion, it is recommended to use in combination with a smooth sheet, no matter which tape you are going to choose. The tape may leave some glue residuals after removing it from the print sheet surface. Usually, these can be washed with IPA or with water and dishwasher soap, but again, double-check the <a href="http://help.prusa3d.com/article/smooth-steel-sheet_196550">steel sheet maintenance articles</a> before washing them.</p>
<div class="warning-callout">If you decide to use other separation materials or adhesives, don’t forget to check compatibility with our print sheets. For example, ABS juice should not be used in combination with textured or satin sheets.</div>
<h3>Removing the print</h3>
<p>One last thing: <strong>always remove the prints by removing and bending the sheet only after they are cooled down.</strong> The print will go off easily without the necessity of using various spatulas, knives, or anything else.</p>


Print surface preparation

<p>Sometimes it is necessary to reinstall an older version of the firmware. The method to <a href="http://help.prusa3d.com/article/how-to-update-firmware-mk4-s-mk3-9-s-mk3-5-s-xl_453086">update the firmware</a> only allows newer firmware versions to be flashed. To flash the same firmware, or an older one, follow the steps below.</p>
<div class="tip-callout">If it repeatedly only boots the printer and gives you the home screen try to <a href="http://help.prusa3d.com/article/sd-cards-and-usb-drives_112291">format your USB flash-drive</a> or try a different one. Even if the flash drive works with G-Codes and printing, it may not work for flashing the firmware.</div>
<ol>
<li>To find the older versions, go to the <a href="https://help.prusa3d.com/downloads">Downloads</a> page, select your printer, and click on <strong><span style="color: #e67e23;">Older versions</span></strong>.</li>
</ol>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2024/06/2d27f0914e1eb33fe468242efccbd072.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="How to downgrade firmware (MK3.5/MK3.9/MK4/XL)" alt="" width="700" height="328" loading="lazy" /></p>
<ol start="2">
<li>Load the .bbf file directly into the root folder of the USB drive.</li>
<li>Insert the drive into the printer.</li>
<li>Push the reset button, and once the printer logo appears on the screen, press and hold the knob.</li>
<li>On the new screen, confirm the update by selecting the "FLASH" button and pressing the knob.</li>
</ol>
<h3>Factory Reset</h3>
<p>If you do a hard <a href="http://help.prusa3d.com/article/factory-reset-mk4-s-mk3-9-s-mk3-5-s-mini-xl_421206">Factory Reset</a>, the firmware that is in the USB will also be installed in the printer, so this can be used as a way to update the firmware.</p>


How to downgrade firmware (MK4/S, MK3.9/S, MK3.5/S, XL)

<p>It is recommended to regularly take some time to maintain your printer. This should be done even if the printer is working perfectly. <strong>The inspection and maintenance of its various components should be done every couple of hundred hours of print-time.</strong> This guide is valid for the <strong>Original Prusa MK3.5 and MK3.5S</strong>. </p>
<h3>Useful tools:</h3>
<p><strong>Besides the usual tools, such as Allen keys, needle-nose pliers, and IPA + paper towels, you might need:</strong></p>
<ul>
<li><strong>Lubricant:</strong> the best option is the Prusa lubricant. One is sent with the printer, but it can also be found in our <a href="https://www.prusa3d.com/product/prusa-lubricant-applicator-set-5g/">e-shop</a>. Other recommended lubricants are Super Lube 210XX, GLEIT-µ HF 400, and Mogul LV 2-EP. We do not recommend lubricants with a very high viscosity.</li>
</ul>
<div class="warning-callout"><strong>Do not apply lubricant on the trapezoid nuts or the threaded lead screws of the Z-axis!</strong></div>
<ul>
<li><strong>Compressed air:</strong> also known as canned air. Be sure not to hold it upside down while spraying - otherwise, you could damage any electronic components while trying to clean them.</li>
<li><strong>Brush:</strong> a small brass brush is an ideal tool for cleaning the Bondtech filament pulleys. If you don't have a brass brush any brush with hard bristles will do the job. Alternative: you can use the acupuncture needle that comes with the original printer or a toothpick.</li>
</ul>
<h3>Axes check</h3>
<p><strong>What to check on your printer:</strong></p>
<ul>
<li><span style="color: #000000;"><strong>Smooth rods:</strong> scratches/grooves - take each rod between two/three fingers and move them slowly from one end of the rod to another, while rotating the fingers around the rod. If you notice any scratch, verify it with your fingernail. </span></li>
<li><strong>Bearings:</strong> Clean and lubricate the bearings and rods as shown <a href="http://help.prusa3d.com/guide/maintenance-tips_23200">this guide</a>. Despite cleaning and lubricating the smooth rods, it can happen that the axes' movement is still not smooth. In this case, please remove the bearings from the printer and lubricate them from the inside with a pea-sized amount of lubricant.</li>
<li><span style="color: #000000;"><strong>Belt pulleys:</strong> any debris around the belt pulleys and belts should be immediately removed to ensure smooth operations. Also, check if the set screw of the belt pulley is firmly secured on the flat side of the motor shaft.</span></li>
<li><span style="color: #000000;"><strong>Idler screw</strong> (M3x40 with the spring on it) is not overtightened or too loose. Generally, the head of the screw, on the left side, should be about flush with the printed parts of the extruder. Details on the ideal tension of the idler screw can be found in <a href="http://help.prusa3d.com/article/idler-screw-tension_177367">Idler screw tension</a>.</span></li>
<li><span style="color: #000000;"><strong>Y-axis and X-axis belts:</strong> Both of the belts should be tight enough to sound like a low bass note when plucked. For details on adjusting the belt tension <a href="http://help.prusa3d.com/article/adjusting-belt-tension-mk4-s-mk3-9-s-mk3-5-s-mk3-s_112380">please see this article</a>.</span></li>
</ul>
<h3>Flexible steel sheet</h3>
<div class="warning-callout">For cleaning and preparing the steel sheet, follow the instructions in the <a href="http://help.prusa3d.com/article/flexible-steel-sheets-guidepost_2195">steel sheet guidepost</a>. It contains instructions specific to all steel sheet types. </div>
<div>All flexible steel sheets should be cleaned regularly to ensure adhesion, but the exact methods and washing solutions can differ depending on your type of sheet.</div>
<h3>Fans</h3>
<p>The Original Prusa MK3.5 can spot if any of the fans stop spinning. However, that does not mean you should not check them during maintenance. Dust or plastic build-up can decrease their efficiency or even damage them.</p>
<p>A cotton swab can also be used to clean off dust and debris from the propeller or canned air will clear the dust. Tweezers can be used to take out any plastic strands. <strong>Hold the propeller</strong> <strong>of the fan to prevent it from spinning while cleaning it with canned air</strong>. Otherwise, it can get damaged. Clear away any debris that may be stuck and check that it can rotate freely. </p>
<h3>Extruder driver gear</h3>
<p>The MK3.5 is equipped with two Bondtech gears, made of hardened carbon steel. One is the <strong>pulley gear,</strong> secured on the extruder's motor shaft by a set screw. The other is the <strong>idler gear</strong>, which spins freely mounted on the idler door. <strong>If you have had a clog, they can also have collected residue grinding the filament</strong> which will, in turn, reduce their grabbing force on the filament. </p>
<p><strong>Regular cleaning and lubrication will:</strong></p>
<ul>
<li>Reduce wear and noise.</li>
<li>Increase the grabbing force on the filament.</li>
<li>Lower friction between the two pulley gears.</li>
<li>Protect against rust. </li>
</ul>
<p>If you're cleaning the gear inside the extruder without removing the extruder motor first, be sure to cover the PTFE tube to avoid any debris falling in. You can use a cotton swab - it will reliably cover the tube without damaging it). After you're done cleaning, give it a good puff of air to clear any remains, while the PTFE tube is still covered.</p>
<p>Open the extruder idler door by releasing the screw on the left side of your extruder.</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/2020/12/ee967edc46e92f22_painted-1536x1152.jpeg" alt="" width="500" height="375" loading="lazy" /></p>
<p>Both hobbed gears can have a build-up of filament shavings stuck in the grooves. Using a brass brush, clean what you can, then rotate the gear a few degrees and repeat until you do a full turn. They can also be cleaned one at a time using the acupuncture needle that comes with the printer.</p>
<p>The gears can be covered by rust. There is no need to worry. The gears themselves should not be damaged. Remove any problematic bits of filament and clean them with a brush. </p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/bontechgear.jpg" sizes="100vw" srcset="Bondtech gears on an MK3" alt="bontech gears" width="498" height="350" loading="lazy" /></p>
<p>Make sure the Bondtech pulley gear is aligned with the path of the filament and secured on the flat side of the motor shaft. Also, check that the shaft of the idler gear goes through both "ears" of the Extruder-Idler-door plastic part and spins freely. You can find a more detailed guide in <a href="http://help.prusa3d.com/article/checking-re-aligning-the-bondtech-gear-mk3-5-s-mk3s-mk2-5s_133176">Checking/re-aligning the Bondtech gear (MK3.5/S, MK3S/+, MK2.5S)</a>.</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/bondtechallign.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/bondtechallign-300x290.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/bondtechallign-413x400.jpg 413w, https://cdn.help.prusa3d.com/wp-content/uploads/bondtechallign-768x743.jpg 768w, https://cdn.help.prusa3d.com/wp-content/uploads/bondtechallign-620x600.jpg 620w" alt="" width="413" height="400" loading="lazy" /></p>
<p>Apply a tiny amount of the grease only to the teeth protruding outwards from the gear. <strong>Make sure that the lubricant never gets in contact with the filament teeth.</strong> Do not use oil-based lubricant as it may spread to unwanted sections, like where the filament is fed into the hotend.</p>
<p><span style="color: #000000;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://cdn.help.prusa3d.com/wp-content/uploads/iddlegear.jpg" sizes="100vw" srcset="https://cdn.help.prusa3d.com/wp-content/uploads/iddlegear-300x134.jpg 300w, https://cdn.help.prusa3d.com/wp-content/uploads/iddlegear-600x267.jpg 600w" alt="idlegear" width="618" height="275" loading="lazy" /></span></p>
<h3>Electronics</h3>
<p>It is a good practice to check and optionally reconnect the electrical connectors on the <strong>xBuddy board</strong> every 600-800 hours of printing.</p>
<div class="warning-callout">Before touching the electrical connections, please make sure that the printer is off, and unplugged from the main power source.</div>
<p>To access the xBuddy board, loosen four M3x6 screws to remove the metal box cover. To access the lower part of the xBuddy board, loosen two M3x10 screws from the bottom cover, and remove the cover. </p>
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<ul>
<li>Check if there are any pinched or worn cables on the printer.</li>
<li>Open the electronics casing and blow compressed air in between the cables to get rid of dust.</li>
<li>Check the connection of all of the wires on the xBuddy board. Especially pay attention to the cables from the PSU (power source) and heaters. Make sure they are inserted all the way in and well-tightened.</li>
</ul>
<h3>Nozzle change</h3>
<p>Putting an exact number on how long a nozzle will last is very difficult, as it depends on how much you print, what types of filament you use, and how often you change between filament types. <strong>It is not the first thing you should look to if you are experiencing extrusion issues</strong>, but if the printer has been in use for more than 3-6 months and you are getting poor print quality, even after doing the mentioned maintenance, you may want to consider <a href="http://help.prusa3d.com/article/changing-or-replacing-the-nozzle-mk2-5-s-mk3-s-mk3-5-s_2069">replacing the nozzle</a>.</p>
<h3>Firmware and software</h3>
<p>You should always be using the latest <strong>stable</strong> firmware version that we have published for your specific printer model. You can check the firmware version you have in the <em>LCD menu - Info - Version info</em>.</p>
<p><a href="http://help.prusa3d.com/article/how-to-update-firmware-mk4-s-mk3-9-s-mk3-5-s-xl_453086"> See this article</a> to flash the fimware on your <strong>MK3.5/S</strong>.</p>
<p>We also recommend using the latest version of our <a href="http://help.prusa3d.com/article/install-prusaslicer_1903">PrusaSlicer</a>, as it enables you to <strong>enjoy all the features of your printer</strong>. It even saves information about the printer model, nozzle diameter, and firmware version directly into the g-code file so that the printer can warn you if anything is out of date or incompatible.</p>


Regular printer maintenance (MK3.5/S)

How to replace a Heatbed Thermistor (MK4/S, MK3.9/S, MK3.5/S)

How to use accelerometer (MK3.5/S)


<ul>
<li>Prusa Connect integration</li>



<li>Prusa Account integration</li>



<li>Improved UI</li>



<li>Improved G-code Viewer</li>



<li>New system profile updating system</li>



<li>Single Perimeter for top and bottom layers</li>



<li>Extended SLA layer separation configuration</li>



<li>Bug fixes</li>
</ul>


2.8.0


<ul>
<li>Issues with numeric keyboard repaired (MK4/S, MK3.9/S, MK3.5/S, XL)</li>



<li>Returned nozzle diameter setup (XL)</li>



<li>Printhead position during calibrations changed (MK4/S, MK3.9/S, MK3.5/S)</li>



<li>Cold pull (XL)</li>
</ul>


6.1.3

1.00


<ul>
<li>Improved menu bar, the menu no longer hides under a button</li>



<li>Two new parameters (Abrasive material and High flow nozzle) for G-Code checks</li>



<li>Improved automatic orientation of bridges</li>



<li>Number of bugfixes</li>
</ul>


Original Prusa MK3.5S

Articles