What to do with the old parts?

Advice for printing nylon through fine screen

Particularly layer lines

Single Extruder Multi Material Mode does not ask for filament change and prints everything with first filament

Cura profiles?

MMU3

Shipping information

<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.&nbsp;</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.&nbsp;</strong></p>
<p><img decoding="async" loading="lazy" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/first_layer-768x433-1.jpg" sizes="100vw" srcset="https://help.prusa3d.com/wp-content/uploads/first_layer-768x433-1-600x338.jpg 600w, https://help.prusa3d.com/wp-content/uploads/first_layer-768x433-1-300x169.jpg 300w" alt="" width="600" height="338"></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-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" loading="lazy" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-01.jpg" sizes="100vw" srcset="https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-01-300x62.jpg 300w, https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-01-600x125.jpg 600w" width="600" height="125" 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.&nbsp;</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>
<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://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-02.jpg" sizes="100vw" srcset="https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-02-300x119.jpg 300w, https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-02-600x238.jpg 600w, https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-02-768x305.jpg 768w, https://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" loading="lazy" src="https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-03fix-2.jpg" sizes="100vw" srcset="https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-03fix-2-600x214.jpg 600w, https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-03fix-2-800x286.jpg 800w, https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-03fix-2-300x107.jpg 300w, https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-03fix-2-768x274.jpg 768w, https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-03fix-2-1536x548.jpg 1536w, https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-03fix-2-2048x731.jpg 2048w" alt="" width="1121" height="400"></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!&nbsp;</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://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-04-300x119.jpg 300w, https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-04-600x238.jpg 600w, https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-04-768x305.jpg 768w, https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-04-800x318.jpg 800w" src="https://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://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-05-300x119.jpg 300w, https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-05-600x238.jpg 600w, https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-05-768x305.jpg 768w, https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-05-800x318.jpg 800w" src="https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-05.jpg"></p>
<h3>When to run the First layer calibration</h3>
<p>Generally, the&nbsp;<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><strong><img decoding="async" loading="lazy" style="float: right;" src="https://help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg.jpg" sizes="100vw" srcset="https://help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-400x400.jpg 400w, https://help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-600x600.jpg 600w, https://help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-300x300.jpg 300w, https://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://help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-1-1.jpg" sizes="100vw" srcset="https://help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-1-1-400x400.jpg 400w, https://help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-1-1-600x600.jpg 600w, https://help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-1-1-300x300.jpg 300w, https://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://help.prusa3d.com/wp-content/uploads/prusament-petg-jet-black-1kg.jpg" sizes="100vw" srcset="https://help.prusa3d.com/wp-content/uploads/prusament-petg-jet-black-1kg-400x400.jpg 400w, https://help.prusa3d.com/wp-content/uploads/prusament-petg-jet-black-1kg-600x600.jpg 600w, https://help.prusa3d.com/wp-content/uploads/prusament-petg-jet-black-1kg-300x300.jpg 300w, https://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://help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-2.jpg" sizes="100vw" srcset="https://help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-2-400x400.jpg 400w, https://help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-2-600x600.jpg 600w, https://help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-2-300x300.jpg 300w, https://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://help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-3.jpg" sizes="100vw" srcset="https://help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-3-400x400.jpg 400w, https://help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-3-600x600.jpg 600w, https://help.prusa3d.com/wp-content/uploads/prusament-petg-prusa-orange-1kg-3-300x300.jpg 300w, https://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://help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-1.jpg" sizes="100vw" srcset="https://help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-1-400x400.jpg 400w, https://help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-1-600x600.jpg 600w, https://help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-1-300x300.jpg 300w, https://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://help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg.jpg" sizes="100vw" srcset="https://help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-400x400.jpg 400w, https://help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-600x600.jpg 600w, https://help.prusa3d.com/wp-content/uploads/prusament-petg-urban-grey-1kg-300x300.jpg 300w, https://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

<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-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> 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; F. autoload.</em></li>
<li>Still being in the <em>Menu</em>, go to <em>Settings</em> and choose <em>Disable steppers</em>. <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, 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://help.prusa3d.com/wp-content/uploads/idler2.jpg" sizes="100vw" srcset="https://help.prusa3d.com/wp-content/uploads/idler2-300x300.jpg 300w, https://help.prusa3d.com/wp-content/uploads/idler2-400x400.jpg 400w, https://help.prusa3d.com/wp-content/uploads/idler2-768x768.jpg 768w, https://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://help.prusa3d.com/wp-content/uploads/mmus2.jpg" sizes="100vw" srcset="https://help.prusa3d.com/wp-content/uploads/mmus2-300x216.jpg 300w, https://help.prusa3d.com/wp-content/uploads/mmus2-554x400.jpg 554w, https://help.prusa3d.com/wp-content/uploads/mmus2-768x554.jpg 768w, https://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. <em>To speed up the cooling you can engage the print fan at full speed, from LCD menu -&gt; Settings -&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 -&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://help.prusa3d.com/wp-content/uploads/dirty-cold-pull.jpg" sizes="100vw" srcset="https://help.prusa3d.com/wp-content/uploads/dirty-cold-pull-300x214.jpg 300w, https://help.prusa3d.com/wp-content/uploads/dirty-cold-pull-561x400.jpg 561w, https://help.prusa3d.com/wp-content/uploads/dirty-cold-pull-768x548.jpg 768w, https://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://help.prusa3d.com/wp-content/uploads/clean-cold-pull.jpg" sizes="100vw" srcset="https://help.prusa3d.com/wp-content/uploads/clean-cold-pull-300x203.jpg 300w, https://help.prusa3d.com/wp-content/uploads/clean-cold-pull-591x400.jpg 591w, https://help.prusa3d.com/wp-content/uploads/clean-cold-pull-768x520.jpg 768w, https://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 (<em>LCD menu -&gt; Calibration -&gt; Calibrate Z</em>) as pushing on the extruder might have thrown it off balance. Also, turn Autoload of filament back on, if you prefer this feature.</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 (MK3S/MK2.5S)

<p>Every FFF (Fused Filament Fabrication) printer requires a First Layer Calibration, which <strong>sets the vertical "Z" distance between the nozzle and the print surface</strong>. Sometimes this value needs <strong>a slight adjustment</strong> and for this situation, there is an option called "<strong>Live adjust Z"</strong> <em>(as you are mostly tuning it live during the first layers of your print).</em> The reason for adjusting the distance is to mostly <strong>provide better adhesion</strong> of the extruded filament.</p>
<h3><strong>How does it work?</strong></h3>
<p>It is important to know the following:</p>
<ul>
<li>the default value before the First layer calibration starts at zero (0.000) for all printers</li>
<li>to get <strong>closer to the print surface</strong>, turn the knob <strong>counter-clockwise</strong> and further <strong>increase the negative value</strong> (e.g. -0.500 =&gt; -0.600 =&gt; -0.700...)</li>
<li>to get <strong>further from the print surface</strong>, turn the knob <strong>clockwise</strong> and continue <strong>lowering the negative value</strong> (e.g. -0.700 =&gt; -0.600 =&gt; -0.500...)</li>
</ul>
<p>The values of the <em>Live adjust Z</em> are typically in the range of -1.500 to -0.200. Going above zero into the positive values is not possible, this indicates either an issue with the measuring sensor (M.I.N.D.A., P.I.N.D.A., SuperPINDA) or incorrect alignment.</p>
<p>The correctly assembled print head has <strong>the sensor always slightly above the nozzle</strong>, never at an equal level or below the nozzle (see the picture below). <em>The exact position can slightly vary, use the last chapter of the assembly manual of your printer to set the rough distance.</em></p>
<p style="text-align: center;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/XYZ-Calibration-MK3-and-MK3S-04.jpeg" alt="" width="718" height="350" loading="lazy" /></p>
<p style="text-align: center;"><em>Example of the MK3S extruder</em></p>
<h3>Live Adjust Z (while printing)</h3>
<p>The most common approach is to perform the <em>Live adjust Z</em> during the print. Go to <em>LCD Menu -&gt;</em> <span style="color: #000000;" data-hd-color="#000000" data-hd-highlight=""><em>Live adjust Z.</em></span> This will show the <span style="color: #000000;" data-hd-color="#000000" data-hd-highlight=""><em>Live adjust Z</em></span> value you have set in the First layer calibration. From here you can adjust it by rotating the knob.</p>
<p>The <strong>Original Prusa MK4</strong> and <strong>Original Prusa XL</strong> are equipped with a loadcell, which will calibrate the first layer automatically. In case you would still like to fine-tune it, you can long-press the knob while the first layer is printed.</p>
<p><img decoding="async" style="max-height: 300px; display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2022/05/Live-adjust-z-1-1.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="https://help.prusa3d.com/wp-content/uploads/2022/05/Live-adjust-z-1-1-600x194.jpg 600w, https://help.prusa3d.com/wp-content/uploads/2022/05/Live-adjust-z-1-1-800x258.jpg 800w, https://help.prusa3d.com/wp-content/uploads/2022/05/Live-adjust-z-1-1-300x97.jpg 300w, https://help.prusa3d.com/wp-content/uploads/2022/05/Live-adjust-z-1-1-768x248.jpg 768w, https://help.prusa3d.com/wp-content/uploads/2022/05/Live-adjust-z-1-1.jpg 1600w" width="600" height="194" loading="lazy" data-hd-height="300px" data-hd-align="center" /></p>
<p style="text-align: center;"><em>Example of the MK3S menu</em></p>
<div>
<div class="tip-callout">PRO tip: shortcut from the main screen, while printing the first few layers press and hold the knob for a few seconds to access the <em>Live adjust Z</em> screen.</div>
</div>
<div>
<div class="warning-callout"><strong>Adjusting Live adjust Z value while printing is permanent</strong>, not only for the ongoing print! The new value will also remain after you turn OFF the printer.</div>
</div>
<div>In the picture below you can see examples of different <em>Live adjust Z</em> values. If the nozzle is too high from the surface, the filament won't stick properly (left), if the nozzle is too close to the surface, the filament won't be able to "flow out" leading to a potential clog of the nozzle (right).</div>
<p><img decoding="async" src="https://help.prusa3d.com/wp-content/uploads/First-Layer-Calibration-04.jpg" alt="" width="1132" height="450" loading="lazy" /></p>
<h3>Live Adjust Z (before the print)</h3>
<p>You can also change the value while the printer is at rest from <em>LCDMenu -&gt; Settings -&gt; Live adjust Z.</em> You will see the value set previously during the First layer calibration, and from here you can adjust it by rotating the knob.</p>
<p><img decoding="async" style="max-height: 300px; display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2022/05/Live-adjust-z-2.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="https://help.prusa3d.com/wp-content/uploads/2022/05/Live-adjust-z-2-600x194.jpg 600w, https://help.prusa3d.com/wp-content/uploads/2022/05/Live-adjust-z-2-800x258.jpg 800w, https://help.prusa3d.com/wp-content/uploads/2022/05/Live-adjust-z-2-300x97.jpg 300w, https://help.prusa3d.com/wp-content/uploads/2022/05/Live-adjust-z-2-768x248.jpg 768w, https://help.prusa3d.com/wp-content/uploads/2022/05/Live-adjust-z-2.jpg 1600w" width="600" height="194" loading="lazy" data-hd-height="300px" data-hd-align="center" /></p>
<p style="text-align: center;"><em>Example of the MK3S menu</em></p>
<p><strong>The Live adjust Z should be used only to fine-tune the distance</strong>. For example, PETG and other high-temperature materials require to be squished in the surface slightly more as they tend to warp (lift up), compared to the PLA. If you have replaced the sensor or disassembled the print head (extruder) you should run the <a href="http://help.prusa3d.com/article/first-layer-calibration-i3_112364">First Layer Calibration (i3)</a> instead.</p>
<div> </div>


Live adjust Z

Original Prusa Curing and Washing Machine (CW1S) is a recommended accessory for the Original Prusa SL1S

Original Prusa CW1 to CW1S platform upgrade

Original Prusa Enclosure assembly

Original Prusa i3 MK3/MK3S/MK3S+ to MK3.9 upgrade

Original Prusa i3 MK3/MK3S/MK3S+ to MK4 upgrade

Original Prusa MK4 kit assembly

Original Prusa MMU3 Assembly

The Original Prusa i3 MK3S+ is the successor of the award-winning Original Prusa i3 MK2S 3D printer.

Original Prusa i3 MK3S+ kit assembly

Original Prusa XL Single-Tool (Assembled)

Original Prusa SL1 to SL1S SPEED upgrade

Original Prusa XL Single-Tool (Semi-Assembled)

Original Prusa MINI+ kit assembly

Original Prusa XL Dual-Head (Assembled)

The Original Prusa MINI+ is a compact 3D printer with all the bells and whistles you would expect from the creators of the award-winning Original Prusa i3 MK2 and MK3S!

Original Prusa MINI+ semi-assembled

Original Prusa XL Dual-Head (Semi-Assembled)

Original Prusa i3 to MMU2S upgrade

Original Prusa XL Five-Head (Assembled)

Original Prusa i3 MK3/MK3S to MK3S+ upgrade

Original Prusa XL Five-Head (Semi-Assembled)

Original Prusa SL1 3D printer is based on the MSLA printing process. Unlike Original Prusa i3 machines, this printer uses a high-resolution LCD panel and a UV LED to cure thin layers of resin to achieve an unprecedented level of detail.

Original Prusa SL1 kit assembly

The Original Prusa i3 MK3S is the successor of the award-winning Original Prusa i3 MK3 3D printer.

Original Prusa i3 MK3S kit assembly

Original Prusa i3 MK1 to MK2 upgrade

Original Prusa XL - beta test

Original Prusa i3 Plus 2.85 mm to 1.75 mm upgrade

Original Prusa i3 Plus 1.75 mm to MK2S upgrade

Original Prusa i3 Plus 1.75 mm kit assembly

Original Prusa i3 MK2 to MK2S upgrade

Original Prusa i3 MK2/S to MMU1 upgrade

The Original Prusa MINI/MINI+ is a compact 3D printer with all the bells and whistles you would expect from the creators of the award-winning Original Prusa i3 MK2 and MK3S!

Original Prusa MINI assembly

Original Prusa i3 MK2S is a successor to Original Prusa i3 MK2 with small hardware tweaks for easier assembly and improved reliability.

Original Prusa i3 MK2S kit assembly

Original Prusa i3 MK2 kit assembly

Original Prusa i3 MK2S to MK3 upgrade

The Original Prusa i3 MK3 is the successor of the award-winning Original Prusa i3 MK2 3D printer.

Original Prusa i3 MK3 kit assembly

Original Prusa i3 MK3 to MK3S upgrade

Original Prusa i3 MK2 MMU1 to MK2.5S MMU2S

Original Prusa i3 MK2 to MK3S upgrade

Original Prusa i3 MK3/MK2.5 to MMU2 v1.01

Original Prusa i3 MK2.5 to MK2.5S upgrade

Original Prusa i3 MK2 to MK2.5S upgrade

Assembly manuals

Printables Clubs

Printables

Basic calibration

Advanced calibration

What to do when the printer reports an error message during calibration.

Calibration Error Messages

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

Slicing

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

Printer troubleshooting

QR Error codes

Print Error Messages

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

Troubleshooting

Nozzles

Octoprint

Printer simulator

Protective Shields

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

3rd party accessories & Other projects

About PrusaSlicer

Configuration and profiles

User interface

Input/output

Left toolbar

Top toolbar

Print settings

Filament settings

Printer settings

Advanced features

Multi-material slicing

SLA slicing

Other (PrusaSlicer)

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

PrusaSlicer

1. Introduction

2. MMU2S Disassembly (UPG)

3. MMU2S Buffer Disassembly (UPG)

4. Idler Body Assembly

5. Selector Assembly

6. Pulley Body Assembly

7. Cassette Buffer Assembly

8. Spool holder Assembly

9B. MK3S+ Extruder mod (KIT)

9C. MK3S+ Extruder (UPG)

10B. MK3S+ Setup and Calibration

11. First Flight

<h3>What happened?</h3>
<p>Before it can align with any of the filament positions, the Idler inside the MMU unit needs to be “homed” to determine its position. First, the Idler moves to one end of the travel (endstop). Then, it moves to the other endstop, while measuring the angle between the end stops. The idler homes after the unit starts up has been reset or after another error occurred.</p>
<p>In case it can’t find the first homing endstop or the distance between the two endstops differs from the expected value, the printer will show an error. </p>
<p>Distance between the Idler endstops: 225 degrees <br />Allowed deviation: 10 degrees</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2023/07/a145b287aabbda1b90de462656d26eec.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Idler cannot home #04125 (MMU3)" alt="" width="450" height="338" loading="lazy" /></p>
<div class="note-callout">Endstops are detected using the StallGuard function. Note that the Stallguard readings are ignored while the Idler moves over the filaments to mitigate false readings.</div>
<h3>How to fix it?</h3>
<p>The issue is usually mechanical. If you get this error, check the following items:</p>
<ul>
<li>Verify there is no debris around the Idler and that it can move freely.</li>
<li>Release the idler tension screws slightly. If it is too tight, it will disable the Idler from moving freely.</li>
</ul>
<table style="border-collapse: collapse; width: 100.026%;" border="0">
<tbody>
<tr>
<td style="width: 48.7906%;"><img decoding="async" loading="lazy" src="https://help.prusa3d.com/wp-content/uploads/2023/07/ea920625436a6187ac92690ebc85c768_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Idler cannot home #04125 (MMU)" alt="" width="400" height="1152" /></td>
<td style="width: 48.7906%;"><img decoding="async" loading="lazy" src="https://help.prusa3d.com/wp-content/uploads/2023/07/22540a2159a7722756db85aae814537f_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Idler cannot home #04125 (MMU)" alt="" width="400" height="1152" /></td>
</tr>
</tbody>
</table>
<ul>
<li style="list-style-type: none;"> </li>
<li>Verify is the <span style="color: #2dc26b;"><strong>Idler Coupler</strong> </span>is attached properly. Check both <strong>grub screws on the Idler Coupler</strong> are tightened and that one of the screws is facing the flat part of the motor shaft. Make sure the Idler doesn’t push against the Idler body so that it can rotate freely.</li>
</ul>
<table style="border-collapse: collapse; width: 100.026%;" border="0">
<tbody>
<tr>
<td style="width: 48.7906%;"><img decoding="async" loading="lazy" src="https://help.prusa3d.com/wp-content/uploads/2023/07/1b1253dfa86ccc937ae4002201d6449e_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Idler cannot home #04125 (MMU)" alt="" width="400" height="1152" /></td>
<td style="width: 48.7906%;"><img decoding="async" loading="lazy" src="https://help.prusa3d.com/wp-content/uploads/2023/07/f49ca29285770b3c4c1f58f1ef10737c_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Idler cannot home #04125 (MMU)" alt="" width="400" height="300" /></td>
</tr>
</tbody>
</table>
<ul>
<li>Especially the first time you are running the MMU, check that the motors are connected in the correct order.</li>
<li>Verify all the bearings can move freely and that the center shaft at the end is inserted into the Idler properly.</li>
<li>In some very specific cases or on modified units or in other unsupported setups; changing the stall guard thresholds might help.</li>
<li>In case you are using the older MMU2S unit, check the <a href="http://help.prusa3d.com/article/mmu2s-idler-unable-to-move-freely_1996">MMU idler unable to move freely article</a>.</li>
</ul>


Idler cannot home #04125 (MMU)

<h3>What happened?</h3>
<p>The Main Control Unit on the MMU control board has detected a power-related issue.</p>
<h3>How to fix it?</h3>
<p>Verify all the cables are in good condition and all the connections are stable.</p>
<div class="warning-callout">Do not move, connect or disconnect the cables while the printer is on!</div>
<div>In case the issue persists, contact our <a href="http://help.prusa3d.com/article/customer-support_2287">Customer support</a>.</div>


MMU MCU Error #04306 (MMU)

<div class="note-callout">This procedure is the same for the MMU3 and MMU2S units running firmware 3.0.0 or newer. In case you are running MMU2S with older FW, please go to <a href="http://help.prusa3d.com/article/factory-reset-mmu2s-pre-firmware-1-0-6_1920">Factory reset (MMU2S pre firmware 1.0.6)</a>.</div>
<p>When upgrading the MMU2S firmware from firmware 1.0.6 (or lower) to 3.0.0 (or higher), or when you find a severe issue with the MMU, you might need to perform a factory reset.</p>
<ol>
<li>On the MMU unit, hold the <strong><span style="color: #f1c40f;">left side button</span></strong> and reset the unit by pushing <strong><span style="color: #2dc26b;">the button</span></strong> on the right side of the MMU with an Allen key.</li>
</ol>
<table style="border-collapse: collapse; width: 100.026%; height: 20.8px;" border="1">
<tbody>
<tr style="height: 20.8px;">
<td style="width: 48.7906%; height: 20.8px;"><img decoding="async" src="https://help.prusa3d.com/wp-content/uploads/2023/07/f431defc3e8325afbc5c9b5cb771ca5f_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Factory Reset (MMU)" alt="" width="1600" height="1200" loading="lazy" /></td>
<td style="width: 48.7906%; height: 20.8px;"><img decoding="async" src="https://help.prusa3d.com/wp-content/uploads/2023/07/6da3e685f0ed55d91383404cebddd4e7_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Factory Reset (MMU)" alt="" width="1600" height="1600" loading="lazy" /></td>
</tr>
</tbody>
</table>
<ol start="2">
<li>Keep the left side button pressed for a few seconds. You will see the LEDs on the MMU flashing quickly in a "snake" motion.</li>
<li>Release the MMU left-side button. As soon as you release it, the MMU EEPROM will be cleared and overwritten with factory default values and will do the selftest.</li>
</ol>
<p>You have successfully reset the MMU. No indication will be shown on the MMU or on the printer.</p>


Factory Reset (MMU)

<h3>What happened?</h3>
<p>While loading to the extruder, as soon as the filament sensor detects a filament the printer performs an automatic loading check. If the check fails, this error is shown. Each failed load might be accompanied by the printer beeping.</p>
<p>The printer’s automatic loading check loads approximately 40mm of filament and then unloads 30mm of it. If the filament sensor stops detecting a filament at any time during the process, the error is shown. This process is very sensitive, so making a precise Filament sensor calibration is needed in order to prevent print defects.</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2023/07/a0439f90aec30ca2278a45e6164a7c07_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Load to Extruder failed" alt="" width="450" height="338" loading="lazy" />  <br />While your MK3S+ is performing the loading check, <strong>solid blocks</strong> should be generated on the bottom of the LCD representing the IR filament sensor <strong>detecting a filament</strong> during the process.</p>
<p>If there is a<strong> line instead</strong> of any blocks (drop in the sensor’s reading), this means that the sensor <strong>stopped detecting</strong> filament at that moment, resulting in a failed loading check. The printer then retries the load. If the cut function is enabled, the MMU tries to cut a filament tip. If the drop while loading persists even during the retries, the printer unloads the filament and shows the error.</p>
<h3>How to fix it?</h3>
<ul>
<li>Redo the <a href="http://help.prusa3d.com/article/ir-filament-sensor-calibration-mmu2s_2245">IR filament sensor calibration (MMU2S)</a>.</li>
<li>In case the issue continues to happen over multiple unloads, check the <a href="http://help.prusa3d.com/article/clogged-nozzle-hotend-mk3s-mk2-5s_2008">extruder for clogging</a>.  Inspect the extruder to rule out a hardware fault.</li>
<li>While the printer is Idle, you can use the Loading test in <em>LCD menu -&gt; Settings -&gt; Loading Test</em> to verify the filament is able to load properly.</li>
<li>Undo the PTFE tube from the FESTO fitting and pull the filament out by hand to inspect it. The last 40cm (15") of each should have no dents in it, or the gears won't be able to grab the filament. Cut off part of the filament with defects such as indentation or a deformed tip. Make sure the filament end is straight and has a sharp tip at the end. Reattach the PTFE tube and hit Retry.</li>
</ul>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.8582%;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2023/01/db89b73cc9e446ce_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="FINDA didn't trigger #04101 (MMU)" alt="" width="400" height="300" loading="lazy" /></td>
<td style="width: 48.8563%;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2023/01/518072e9f17dc738_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="FINDA didn't trigger #04101 (MMU)" alt="" width="400" height="300" loading="lazy" /></td>
</tr>
</tbody>
</table>
<ul>
<li>Inspect the filament spool and the buffer for excessive friction or filament jam. Make sure the filament is able to move freely.</li>
<li>Use only high-quality filaments. Certain poor-quality filaments or very specific types of material might not work correctly with the MMU.</li>
</ul>


Load to extruder failed #04108 (MMU)

<h3>What happened?</h3>
<p>While the MMU unit was unloading a filament, the SuperFINDA sensor inside the selector stayed triggered/detecting a filament, while it shouldn’t. </p>
<div class="note-callout">The superFINDA might be referred to as FINDA on the printer.</div>
<h3>How to fix it?</h3>
<p>Check if the filament has been unloaded or not.</p>
<p>If the filament has been unloaded, but the superFINDA is still triggered, open the Festo fitting connected to the selector, and check if there is anything stuck in the selector (e.g. broken filament, string).</p>
<p>Also, make sure that the superFINDA is working: <a href="http://help.prusa3d.com/article/finda-setup-and-troubleshooting_2250">FINDA setup and troubleshooting</a>.</p>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.8582%;"><img decoding="async" src="https://help.prusa3d.com/wp-content/uploads/2023/02/e629450d7b3be183_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="FINDA: Filam. Stuck #04102 (MMU)" alt="" width="400" height="1200" loading="lazy" /></td>
<td style="width: 48.8563%;"><img decoding="async" src="https://help.prusa3d.com/wp-content/uploads/2023/05/43c60d5d36ece1b67f090c38dcc9faca_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="FINDA: Filam. Stuck #04102 (MMU)" alt="" width="1600" height="1200" loading="lazy" /></td>
</tr>
</tbody>
</table>
<p>In case the filament is stuck between the MMU unit and the extruder, remove the PTFE tube from the FESTO fitting. Remove any debris that might be stuck in the PTFE tube. pull out approx. 40cm of filament and inspect it for indents. If there are any, cut off the damaged part of the filament, re-install the PTFE tube, and hit Retry.</p>
<p>Make sure that the tip of the filament is sharp, and not stringy or expanded so that the issue does not happen again.<img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2023/01/db89b73cc9e446ce_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="FINDA: Filam. Stuck #04102 (MMU)" alt="" width="400" height="300" loading="lazy" /></p>
<p>If there is any debris or broken pieces of filament inside the selector, it can be cleared up using the 1.5mm Allen key, if you remove the FESTO fitting and move the selector all the way to the right. If the SuperFINDA sensor was triggered due to debris / broken filament, the actual filament might be far behind the pulley wheel and might need pushing into the MMU from the back, while retrying the loading operation.</p>
<p>Multi-material operation is sensitive to proper temperature settings. Check that you are using the correct settings for the given material in Slicer. Incorrect nozzle temperatures will cause issues with filament load/unload. Note that with MMU, some 3rd party filaments might behave differently than during the single-material operation even with the same settings.</p>
<p>Some filaments sensitive to moisture might need to be dried out before use. Moist filaments are usually more stringy and this might cause the filaments to jam. You can read more about how to lower the stringing in our <a href="http://help.prusa3d.com/article/stringing-and-oozing_1805">Stringing and oozing</a> article.</p>
<p>It is recommended to use only high-quality filaments. Certain poor-quality filaments or very specific filament types won’t work correctly with the MMU. In this case, change the slicer settings according to the manufacturer's instructions.</p>


FINDA: Filament Stuck #04102 (MMU)

<h3>What happened?</h3>
<p>During Filament loading, either to the MMU unit or to the Nozzle, if the filament does not reach the  SuperFINDA or is not detected, the printer will show an error.</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2023/01/Finda-didnt-triggercrop.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="FINDA didn't trigger #04101 (MMU)" alt="" width="600" height="303" loading="lazy" /></p>
<h3>How to fix it?</h3>
<h4>FINDA</h4>
<p>Follow this guide to make sure that your superFINDA is working and has been properly calibrated: <a href="http://help.prusa3d.com/article/finda-setup-and-troubleshooting_2250">FINDA setup and troubleshooting</a>.</p>
<h4>Assembly</h4>
<ul>
<li>Check if the filament has been grabbed by the idler/pulley. In case it has not, the filament is too far back.</li>
<li>Make sure that the two spring screws on the sides of the MMU unit are properly tightened.</li>
<li>Inspect the filament spool and the buffer for excessive friction or filament jam. Make sure the filament is able to move freely.</li>
<li>Go over the assembly manual and verify if the barrel is in the correct orientation.</li>
<li>Check the pulley gears for any filament remains, and make sure that the teeth are clean.</li>
<li>Check that the corresponding pulley inside the MMU unit is properly aligned with the filament and is clean.</li>
</ul>
<h4>Selector</h4>
<ul>
<li>Verify if the selector is in the correct position for the given filament number. After several unsuccessful retries, the selector will re-home.</li>
<li>Check the selector for any filament remains and filament strings accumulated.</li>
</ul>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2023/01/FINDA_FUNCTION_MMU_CUT-1.gif" sizes="(min-width: 1024px) 820px, 100vw" srcset="FINDA didn't trigger #04101 (MMU)" alt="" width="600" height="295" loading="lazy" /></p>
<h4>Filament</h4>
<ul>
<li>Make sure that the PrusaSlicer settings chosen match the filament you are using.</li>
<li>Check if the filament needs to be dried: <a href="http://help.prusa3d.com/article/drying-filament_332086">Drying filament</a>.</li>
<li>The filaments must have a sharp tip in order to load properly into the printer. If the tip is deformed, bent, or larger in diameter, cut it off.</li>
<li>Inspect the last 40cm (15") of each filament. Make sure there are no dents in it.</li>
<li>If the filament is still not being pulled, check the <a href="http://help.prusa3d.com/article/mmu2s-setup-and-inspection_2233#assembly-inspection">assembly</a>.</li>
</ul>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.8582%;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2023/01/db89b73cc9e446ce_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="FINDA didn't trigger #04101 (MMU)" alt="" width="400" height="300" loading="lazy" /></td>
<td style="width: 48.8563%;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2023/01/518072e9f17dc738_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="FINDA didn't trigger #04101 (MMU)" alt="" width="400" height="300" loading="lazy" /></td>
</tr>
</tbody>
</table>
<p> </p>


FINDA didn't trigger #04101 (MMU)

<h3>What happened?</h3>
<p>It seems, the MMU unit has either an old or an incompatible firmware version.<br />The printer will show you an expected firmware version for the MMU unit.</p>
<p>For example, this error is shown when using the old MMU2S firmware 1.0.6 or below in combination with the newer printer’s firmware such as 3.13 or up on MK3S+. </p>
<h3>How to fix it?</h3>
<p>Make sure that are using the correct up-to-date firmware for both the printer and the MMU unit: <a href="https://help.prusa3d.com/downloads">Firmware download</a>.</p>
<p>If you are not sure which version you have, find the order number from the MMU unit, or take pictures of it, and send it to our <a href="http://help.prusa3d.com/article/customer-support_2287">Customer support</a>.</p>


Firmware update needed #04504 (MMU)

<p>This article is describing the status of the LEDs located on the multi material unit. Together there are five LEDs on the unit that correspond to the five available filament positions. </p>
<div class="warning-callout"><strong>Attention</strong>: MMU3 issues should be primarily resolved using the error codes displayed on the printer's screen. This article explains basic LED statuses and also includes information for developers.</div>
<div class="note-callout">This article is valid for the MMU3 <strong>firmware 3.0.0 </strong>and up. <br />Note that the earlier MMU2S firmware 1.0.6 or below behaves differently.</div>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2023/07/cc78fe05f7942c4acdaf41c0620e402a_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Status LED explained (MMU3)" alt="" width="450" height="338" loading="lazy" /></p>
<h3>During the regular MMU operation: </h3>
<ul>
<li>GREEN solid light: The MMU has a record of the given filament being loaded in the extruder.</li>
<li>GREEN flashing light: There is a loading/unloading process going on.</li>
<li>RED flashing light: There is a loading/unloading error with the given filament. The unit is waiting for user interaction.</li>
<li>RED and GREEN flashing lights: Internal runtime error, refer to the error shown on the printer’s LCD.</li>
</ul>
<h3>MMU Firmware start:</h3>
<p>After the MMU unit has been turned on or restarted, green LEDs light up from positions 5 to 1 shortly (~100ms). Each signalizes one component up and running: </p>
<ul>
<li>LED 5: Shift registers initialization</li>
<li>LED 4: USART initialization</li>
<li>LED 3: SPI communication initialization</li>
<li>LED 2: motion system initialization</li>
<li>LED 1: ADC initialization</li>
</ul>
<p>If the MMU stops in this setup phase (the LEDs stay on and do not turn off), something is wrong with the electronics.</p>
<p>Then, a selftest routine is performed. It checks if the main control board behaves correctly and if all the signals from the microcontroller get to the TMC motor drivers on the control board properly. If the MMU unit suspects the communication with any of the three TMC motor drivers might not behave correctly, an error is shown. In that case, refer to the printer’s LCD screen.</p>
<p>LED lights indicate the ongoing phases of the selftest routine:</p>
<ul>
<li>LED 1: ok (green) / error (red) on STEP signal</li>
<li>LED 2: ok (green) / error (red) on DIR signal</li>
<li>LED 3: ok (green) / error (red) on ENABLE signal</li>
<li>LED 4 indicates which TMC driver is being tested
<ul>
<li>Idler = green</li>
<li>Selector = red</li>
<li>Pulley = green+red</li>
</ul>
</li>
<li>LED 5 is flashing green while the process is still ongoing.</li>
</ul>
<h3>Other LED lights on the unit: </h3>
<p>There are also other less important LED indicators on the unit.</p>
<ul>
<li>A green LED on the MMU3 PD-board addon, on the back of the unit. It signalizes the board receiving power from the printer.</li>
<li>An orange indicator "breathing" on the inside of the MMU unit, on the main control board, signalizes the electronics booting up.</li>
<li>A red indicator on the top of the FINDA sensor signalizes the sensor being powered up and NOT detecting a filament.</li>
</ul>


Status LED explained (MMU3)

<h3>What happened?</h3>
<p>Before it can align with any of the filament positions, the selector on the MMU unit needs to be “homed” to determine its position. For that, the selector moves from one end stop to the other while measuring the distance between them. The selector will home after the unit starts up, has been reset, or after another error occurred.</p>
<p>In case the Selector can't find the first homing endstop, or the distance between the endstops differs from the expected value, the printer will show this error.</p>
<p>Distance between the Selector endstops: 75mm<br />Allowed deviation: 3mm</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2023/07/a145b287aabbda1b90de462656d26eec.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Selector cannot home #04115 (MMU3)" alt="" width="450" height="338" loading="lazy" /></p>
<h3>How to fix it?</h3>
<p>The selector might not move due to obstacles, debris, or remaining filament in its way. Before proceeding, make sure that the path of the selector is clean, and that any filament that has been cut by the selector blade is removed.</p>
<p>Clean also any filament that might be under the selector in the pulley body.</p>
<h4>Clearing the Selector</h4>
<p>Open the front Festo fitting to check the Selector.</p>
<p>If there is filament sticking out from the front PTFE tube, or sticking out from the MMU unit into the selector, take an Allen key to push the filament back.</p>
<p>If the selector has tried to move with the filament still inside it, turn the printer off, and manually turn the motor threaded rod until it aligns with the pulley body and you can pull the filament from the back of the MMU unit or push from the front of the selector with an Allen key. After that, <a href="http://help.prusa3d.com/article/finda-setup-and-troubleshooting_2250">adjust the FINDA height</a>.</p>
<h4>Assembly</h4>
<p>In case the Selector is clean from filaments, check the following items in the <strong>MMU unit assembly</strong>.</p>
<ul>
<li>Verify if the <a href="http://help.prusa3d.com/article/finda-setup-and-troubleshooting_2250"><strong>SuperFINDA</strong></a> sensor reads correctly.</li>
<li>The <strong>trapezoid nut</strong> on the selector motor might be loose or offset to one side. Remake the <a href="http://help.prusa3d.com/guide/6-pulley-body-assembly_328918#331552">Selector motor installation</a>.</li>
<li>The <strong>bushing tubes</strong> should be flush with the body of the Selector.</li>
</ul>
<div class="tip-callout">Both bushing tubes and the trapezoid nut are self-lubricating. Do not apply any lubricant to the trapezoid nut.</div>
<ul>
<li>The selector motor<strong> </strong>must not be loose on the MMU unit body. The top corner screw should be tightened slightly looser compared to the other two. The two screws should be tightened evenly. Remake the <a href="http://help.prusa3d.com/guide/6-pulley-body-assembly_328918#331552">Selector motor installation</a>.</li>
<li>In case you have printed the parts yourself, check if the <strong>printed parts</strong> do not have any surfaces that are lifted.</li>
<li>Especially the <strong>first time</strong> you are using the MMU unit, verify that the motors are connected in the correct order.</li>
</ul>


Selector cannot home #04115 (MMU)

<h3>What happened?</h3>
<p>If during the filament load to nozzle process, the filament sensor in the extruder is not triggered, the printer will show the error.</p>
<h3>How to fix it?</h3>
<h4>Assembly</h4>
<ul>
<li>Remake the <a href="http://help.prusa3d.com/guide/10b-mk3s-setup-and-calibration_334155#339621">filament sensor calibration</a>.</li>
<li>Make sure that the PTFE tube is fully pushed into the Festo fitting, and that the fitting is fully tightened, with no gap.</li>
<li>Open the extruder idler and make sure that there is no leftover filament in the extruder blocking the new filament from loading.</li>
<li>Make sure that the PTFE tube is fully pushed into the Festo fitting.</li>
<li>If you use an alternative MMU-to-Extruder PTFE tube, make sure it is not excessively long.
<p>The original tube is 360mm long. The MMU will automatically adapt to tubes up to 380 mm, but will not work with tubes longer than that.</p>
<p> </p>
<p> </p>
</li>
</ul>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2023/02/301aad2a5342cfd8.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="F sensor didn't trigger #04103 (MMU)" alt="" width="400" height="300" loading="lazy" /></p>
<h4>Filament</h4>
<ul>
<li>The filaments must have a sharp tip in order to load properly into the printer. If the tip is deformed, bent, or larger in diameter, cut it off.</li>
<li>Inspect the last 40cm (15") of each filament. Make sure there are no dents in it.</li>
<li>If the filament is still not being pulled, check the <a href="http://help.prusa3d.com/article/mmu2s-setup-and-inspection_2233#assembly-inspection">assembly</a>.</li>
</ul>
<table style="border-collapse: collapse; width: 100%;" border="0">
<tbody>
<tr>
<td style="width: 48.8582%;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2023/01/db89b73cc9e446ce_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="FINDA didn't trigger #04101 (MMU)" alt="" width="400" height="300" loading="lazy" /></td>
<td style="width: 48.8563%;"><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2023/01/518072e9f17dc738_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="FINDA didn't trigger #04101 (MMU)" alt="" width="400" height="300" loading="lazy" /></td>
</tr>
</tbody>
</table>
<p> </p>


Filament sensor didn't trigger #04103 (MMU)

<h3>What happened?</h3>
<p>Implausible SuperFINDA reading. This error happens when a filament is detected by the SuperFINDA sensor although the MMU doesn’t have a record of any filament being loaded. It is unsure of which position the filament is loaded in so it can’t perform the unload automatically.</p>
<p>This usually happens, if the user was loading a filament manually not using the menu/buttons, or if the printer was restarted while performing a certain load/unload operation without finishing it first.</p>
<h3>How to fix it?</h3>
<ul>
<li>Unload a filament manually or clear the sensors from any filament to continue.</li>
<li>Verify the <a href="http://help.prusa3d.com/article/finda-setup-and-troubleshooting_2250">superFINDA calibration</a>.</li>
<li>Use only the menu on the printer to load or unload a filament during regular use.</li>
</ul>


Unload manually #04506 (MMU)

<h3>What happened?</h3>
<p>Implausible reading by the Filament sensor inside the extruder, while loading a filament. The filament shouldn't be in the extruder yet but is detected there anyway. </p>
<div>
<h3>How to fix it?</h3>
<p>Remake the <a href="http://help.prusa3d.com/article/ir-filament-sensor-calibration-mmu2s_2245">IR filament sensor calibration (MMU2S)</a>. </p>
<p>Open the extruder idler and make sure that there is no leftover filament in the extruder causing the sensor to trigger too early.</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2023/02/301aad2a5342cfd8.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="F sensor too early #04106 (MMU)" alt="" width="400" height="300" loading="lazy" /></p>
</div>


Filament sensor too early #04106 (MMU)

<h3>What happened?</h3>
<p>The printer is trying to initiate communication with the MMU unit, but there is no response.</p>
<h3>How to fix it?</h3>
<p>Check the following:</p>
<ul>
<li>Make sure the MMU unit is present on the printer. If not, either connect the MMU unit back or turn the MMU off either by selecting Disable MMU or in the printer’s menu.</li>
</ul>
<div class="warning-callout">Do not move, connect, or disconnect the cables while the printer is on!</div>
<ul>
<li>Verify all the cables are connected properly. Do not move, connect or disconnect the cables while the printer is on!</li>
<li>Verify all the cables are in good condition and the connections are stable. </li>
<li>Make sure your MMU3 unit is correctly assembled with the PD-board addon attached.</li>
<li>Make sure you are using the correct up-to-date <a href="https://help.prusa3d.com/downloads">firmware</a> for both the printer and the MMU unit.</li>
</ul>


MMU not responding #04401 (MMU)

<h3>What happened?</h3>
<p>When the MMU unit unloads a filament from the extruder, the filament sensor inside the extruder should stop detecting the filament. In case it does not, this error appears.</p>
<div class="tip-callout">If there is an issue with unloading, the MMU gears might grind the filament. In case this happens, cut off about 40 cm at the of the filament, otherwise, errors might happen later.</div>
<h3>How to fix it?</h3>
<p>Check the PTFE tube that leads from the MMU unit to the extruder, and see if the filament has been unloaded or not.</p>
<p>In case the filament has been unloaded, but the printer shows this error, remake the <a href="http://help.prusa3d.com/article/ir-filament-sensor-calibration-mmu2s_2245">filament sensor calibration</a>. </p>
<h4>Extruder</h4>
<p>In case the filament has not been unloaded, make sure that the nozzle is heated for the filament you are using. Then open the Extruder idler screw and the Festo fitting on the top of the extruder, and manually pull the filament. Note that some force might be necessary.</p>
<p>On the MK3S, check the <a href="http://help.prusa3d.com/article/checking-re-aligning-the-bondtech-gear-mk3s-mk2-5s_133176">alignment of the idler door and the Bondtech gears</a>. On the idler door, check if the gear is moving freely and that the shaft is connected to both sides of the plastic part.</p>
<p>Make sure that there is no debris or pieces of filament in the idler door or extruder gears causing the filament sensor to falsely trigger.</p>
<table style="border-collapse: collapse; width: 100.026%;" border="0">
<tbody>
<tr>
<td style="width: 48.7906%;"><img decoding="async" src="https://help.prusa3d.com/wp-content/uploads/2023/06/894a78e49eb7321e86972a08d529304b_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="F.sensor: Fil. stuck #04104 (MMU)" alt="" width="400" /></td>
<td style="width: 48.7906%;"><img decoding="async" src="https://help.prusa3d.com/wp-content/uploads/2023/06/8c9d9664036f68047bd28115f70ffd9d.jpg" sizes="(min-width: 1024px) 820px, 100vw" srcset="F.sensor: Fil. stuck #04104 (MMU)" alt="" width="400" height="300" loading="lazy" /></td>
</tr>
<tr>
<td style="width: 48.7906%; text-align: center;">MK3S/+</td>
<td style="width: 48.7906%; text-align: center;">MK4</td>
</tr>
</tbody>
</table>
<h4>Filament</h4>
<p>Check that you are using the correct settings for your filament with the manufacturer. Filaments that have a lot of stringing might cause the filament to jam.</p>
<p>Before starting the printer operation again, make sure that the filament is straight and cut into a sharp tip, and that there is no damage on the first 40 cm of the filament.</p>
<p>In case the issue continues to happen over multiple unloads, check the <a href="http://help.prusa3d.com/article/clogged-nozzle-hotend-mk3s-mk2-5s_2008">extruder for clogging</a>.</p>
<p>In case the issue persists due to deformed filament tips, try <a href="http://help.prusa3d.com/guide/how-to-replace-a-hotend-ptfe-tube-mk3s-mk3s-mk2-5s-mmu2s_21664">changing the PTFE tube</a>.</p>
<table style="border-collapse: collapse; width: 100.026%;" border="0">
<tbody>
<tr>
<td style="width: 48.7906%;"><img decoding="async" src="https://help.prusa3d.com/wp-content/uploads/2023/06/1b0b51ab6ebc617ed24250e58decd341_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="F.sensor: Fil. stuck #04104 (MMU)" alt="" width="400" height="1152" loading="lazy" /></td>
<td style="width: 48.7906%;"><img decoding="async" src="https://help.prusa3d.com/wp-content/uploads/2023/06/d4c277f892b2561f479bdfb726ae32bd_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="F.sensor: Fil. stuck #04104 (MMU)" alt="" width="400" height="1152" loading="lazy" /></td>
</tr>
</tbody>
</table>
<p> </p>


Filament sensor: Fil. stuck #04104 (MMU)

<h3>What happened?</h3>
<p>This error happens when the filament change function is triggered. This can happen by:</p>
<ul>
<li>Filament change command in the printer’s menu.</li>
<li>Issuing the M600 G-code command.</li>
<li>The printer detects a depleted filament (when the Spooljoin function is off).</li>
</ul>
<p><strong>How to proceed?<br /></strong></p>
<p>Remove the old filament from the MMU unit and replace it with a new one. Click the option Load and select the desired filament position. You can select the one you previously used or a new position.</p>
<p>In case you need to eject the depleted filament out of the front of the MMU unit, select Eject. The Selector will move until the filament slot is free, and the filament will be ejected to the front so that you can pull it out easily.</p>


Filament change #04508 (MMU)

<h3>What happened?</h3>
<p>The filament has been ejected to the front of the MMU unit so that you can remove it.</p>
<div class="tip-callout">This feature is handy in case you are using the Spooljoin function. A depleted filament might be too short in order to be removed easily from the back of the unit. By ejecting it to the front of the unit, you can easily grab it and discard it. </div>
<h3>How to proceed?</h3>
<p>Remove and discard the ejected piece of filament and hit the button on the LCD screen.</p>
<p>If you accidentally triggered the eject function, push the ejected filament back into the MMU unit and make sure it isn’t protruding out of the short front PTFE tubes - so that the selector doesn’t jam later on.</p>


Filament ejected #04507 (MMU)

<h3>What happened?</h3>
<p>Each of the three stepper motors on the MMU unit is controlled by a TMC driver on the control board. In case there is an unexpected communication issue between the main microcontroller and the Idler motor TMC driver on the board, the error is shown.</p>
<h3>How to fix it?</h3>
<p>Make sure you are using the MMU3 with the PD-board addon attached.</p>
<p>Verify all the cables are in good condition and the connections are stable.</p>
<div class="warning-callout">Do not move, connect or disconnect the cables while the printer is on!</div>


TMC driver error #04321 (MMU)

<h3>What happened?</h3>
<p>Each of the three stepper motors on the MMU unit is controlled by a TMC driver on the control board. In case there is an unexpected communication issue between the main microcontroller and the Selector motor TMC driver on the board, the error is shown.</p>
<h3>How to fix it?</h3>
<p>Make sure you are using the MMU3 with the PD-board addon attached.</p>
<p>Verify all the cables are in good condition and the connections are stable.</p>
<div class="warning-callout">Do not move, connect, or disconnect the cables while the printer is on!</div>


TMC driver error #04311 (MMU)

<h3>What happened?</h3>
<p>The selector on the MMU unit needs to move or re-home but a filament inside it is detected unexpectedly by SuperFINDA sensor. The selector can’t proceed because there might be filament in it.</p>
<div>
<h3>How to fix it?</h3>
<p>It is possible to check the FINDA status either by checking the light on top of it or on the LCD.</p>
<p><img decoding="async" style="display: block; margin-left: auto; margin-right: auto;" src="https://help.prusa3d.com/wp-content/uploads/2023/02/35c472d5ac3ff43a_painted.jpeg" sizes="(min-width: 1024px) 820px, 100vw" srcset="Inspect FINDA #04107 (MMU)" alt="" width="400" height="300" loading="lazy" /></p>
<p>If there is no filament under the SuperFINDA sensor but its status is still 1, check the Selector for any leftover filament or debris.</p>
<p>If necessary, recalibrate the <a href="http://help.prusa3d.com/article/finda-setup-and-troubleshooting_2250">superFINDA</a> by following the <a href="http://help.prusa3d.com/guide/10b-mk3s-setup-and-calibration_334155">assembly guide chapter to re-calibrate the SuperFINDA sensor.</a></p>
<p>Clear the selector from any filament or debris causing the SuperFINDA sensor to remain triggered.</p>
</div>


Inspect FINDA #04107 (MMU)

<h3>What happened?</h3>
<p>There were frequent errors detected in the communication between the printer and the MMU unit. The digital communication “messages” between the printer and the MMU unit are checked using the CRC function and verified for reception. If these checks fail multiple times in a row, this error is shown.</p>
<h3>How to fix it?</h3>
<p>Check the following:</p>
<ul>
<li>Make sure the MMU unit is present on the printer. If not, either connect the MMU unit back or turn the MMU off either by selecting Disable MMU or in the printer’s menu.</li>
</ul>
<div class="warning-callout">Do not move, connect, or disconnect the cables while the printer is on!</div>
<ul>
<li>Verify all the cables are in good condition and the connections are stable.</li>
<li>Make sure your MMU3 unit is correctly assembled with the PD-board addon attached.</li>
<li>Make sure you are using the correct up-to-date <a href="https://help.prusa3d.com/downloads">firmware</a> for both the printer and the MMU unit</li>
<li>Verify no source of interference is close to the data cables.</li>
<li>Do not use extending cables.</li>
</ul>


Communication error #04402 (MMU)


<ul>
<li>Organic supports</li>



<li>Automatic support painter</li>



<li>Text embossing tool</li>



<li>Improved cut tool</li>



<li>Adding connectors and dowel pins</li>



<li>Measurement tool</li>



<li>Dynamic overhang speed</li>



<li>Improved Ensure vertical shell thickness</li>



<li>Smart extending of sparse infill</li>
</ul>


2.6.0


<ul>
<li>Initial release for Original Prusa MMU3</li>
</ul>



<ul>
<li>MMU3 firmware support</li>



<li>Features by the Prusa community
<ul>
<li>E3D Revo support</li>



<li>Meatpack support</li>



<li>Do not preheat the heatbed on load/unload</li>



<li>Features and translations</li>
</ul>
</li>



<li>Support for G-Code M850</li>



<li>First Layer Calibration - nozzle diameter</li>



<li>PrusaLink improvements</li>



<li>Build environment with cmake</li>



<li>Known issues</li>
</ul>


3.13.0 (3.0.0)


<ul>
<li>XYZ calibration fixed</li>
</ul>


3.13.1 (3.0.0)


<ul>
<li>New Arrange tool options</li>



<li>New Cut tool options</li>



<li>Per-symbol text projection on surface</li>



<li>Interlocking of painted areas for MMU printing</li>
</ul>


Original Prusa MMU3