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5. Pulley body assembly

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5. Pulley body assembly

5. Pulley body assembly
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Last updated 4 months ago
5. Pulley body assembly
 Difficulty
Moderate
 Steps
35
 Available languages
CSDEESFRITJAPL

Step 1 Tools necessary for this chapter

Tools necessary for this chapter
Tools necessary for this chapter
Please prepare tools for this chapter:
2.5mm Allen key for M3 screws
1.5mm Allen key for nut alignment
Needle-nose pliers for blade assembly
Measurement tool (optional), best is a digital caliper

Step 2 Pulley-body parts preparation

Pulley-body parts preparation
Pulley-body parts preparation
For the following steps, please prepare:
mmu2-pulley-body (1x)
M3nS nut (10x)
Nuts are placed in the pulley-body just for the photograph, no need to arrange them like this ;)

Step 3 Pulley-body assembly (part 1)

Pulley-body assembly (part 1)
Pulley-body assembly (part 1)
Pulley-body assembly (part 1)
Pulley-body assembly (part 1)
Insert four nuts from the top of the pulley-body.
Insert three nuts from the side of the pulley-body.
Finally, insert two nuts from the other side of the pulley-body.
Ensure proper alignment of all nuts using 1.5mm Allen key.

Step 5 Pulley motor parts preparation

Pulley motor parts preparation
Pulley motor parts preparation
Pulley motor parts preparation
Pulley motor parts preparation
For the following steps, please prepare:
Pulley (5x)
M3x10 screw (4x)
625 bearing (1x)
Pulley motor (1x)
Filament with length 10-15 cm (1x)
The filament is not part of the upgrade kit, use any 1.75mm you have. Use a straight filament if possible.
The pulley motor is not included in the MMU1 to MMU2S upgrade kit, see the next step.

Step 6 MMU1 to MMU2S upgrade (part 1)

MMU1 to MMU2S upgrade (part 1)
MMU1 to MMU2S upgrade (part 1)

This step is valid only for those who are upgrading from MMU1 to MMU2S. Everyone else should skip to the Step 9

For the following steps, please prepare:
Shaft coupler (1x)
Shaft 5h9x90 (1x)
Extruder motor (1x)
Use the motor from the disassembled MMU1. This motor is not included in the MMU1-MMU2S upgrade package

Step 7 MMU1 to MMU2S upgrade (part 2)

MMU1 to MMU2S upgrade (part 2)
MMU1 to MMU2S upgrade (part 2)
MMU1 to MMU2S upgrade (part 2)
MMU1 to MMU2S upgrade (part 2)
This step is valid only for those, who are upgrading from MMU1 to MMU2S.
Rotate the flat part of the shaft in the direction of the cable.
Insert bundled pliers to create a gap between the motor and the shaft coupler. If you want to be precise, the gap should be 10 mm.
Place the shaft coupler on the top of pliers and rotate the lock screw against the flat part of the shaft. Tighten the lower screw.
Slightly press on the shaft coupler from the top to ensure the lower lock screw is engaged.

Step 8 MMU1 to MMU2S upgrade (part 3)

MMU1 to MMU2S upgrade (part 3)
MMU1 to MMU2S upgrade (part 3)
This step is valid only for those, who are upgrading from MMU1 to MMU2S.
Insert the shaft into the shaft coupler and rotate the flat part against the lock screw.
Tighten the lock screw.
Even though this motor is labelled "Extruder" consider it "Pulley motor" from now on.

Step 9 Pulley motor assembly (part 1)

Pulley motor assembly (part 1)
Pulley motor assembly (part 1)
Pulley motor assembly (part 1)
Pulley motor assembly (part 1)
First, make sure the motor cable is facing to the left.
Find the flat part of the shaft and rotate it up.
Slide the first pulley on the shaft, ensure the lock screw is on the top (against the flat part of the shaft). Tighten the lock screw just slightly.
The first pulley should be around 30 mm (1.18 inch) from the black "ring" on the motor. Don't tighten the lock screw, you will need to adjust the position later.
Slide the other pulleys in the same orientation (lock screw facing up). Tighten the lock screw on each just slightly.
Exact position of each pulley will be adjusted later.

Step 10 Pulley motor assembly (part 2)

Pulley motor assembly (part 2)
Pulley motor assembly (part 2)
Pulley motor assembly (part 2)
Pulley motor assembly (part 2)
Insert the 625 bearing in the pulley-body. At the end the bearing should "snap" to the opening in the printed part.
Slide in the Pulley motor, the shaft must enter the bearing.
Cable of the motor should be oriented to the left, see the second photo.
Slide two screws M3x10 in the opening on idler-body and tighten them slightly.
Turn the entire assembly upside-down and insert second couple of the M3x10 screws, again tighten them slightly.
Make sure the motor is seated properly (in direct contact with the idler-body), then tighten all four screws. Tighten screws on a diagonal.

Step 11 Pulley adjustment

Pulley adjustment
Pulley adjustment
Pulley adjustment
Pulley adjustment
WARNING: this step is crucial for proper functioning of the Multi Material Upgrade. Please check your alignment multiple times!!!
Push the filament through the pulley body as in the picture.
In case your filament is bent, make sure the bend points down, so the part above the pulley is straight.
Adjust the position of the pulley, the teeth must be directly below the filament.
Check again the proper position relative to the teeth on the pulley.
Make sure the lock screw is still perpendicular to the flat part of the shaft and tighten it. Use reasonable force as you might strip the screw.
Repeat these instructions on the 4 remaining pulleys.

Step 12 Front-PTFE-holder parts preparation

Front-PTFE-holder parts preparation
Front-PTFE-holder parts preparation
Front-PTFE-holder parts preparation
For the following steps, please prepare:
mmu2-front-PTFE-holder (1x)
M3x10 screw (4x)
PTFE 4x2x19 (5x)
Note the PTFE tube has one end chamfered, please pay attention to the instructions about proper orientation.
The PTFE tubes can be also in white color, other parameters are same as the orange version.

Step 13 Front-PTFE-holder assembly

Front-PTFE-holder assembly
Front-PTFE-holder assembly
Front-PTFE-holder assembly
Front-PTFE-holder assembly
Insert the PTFE tubes in the pulley-body all the way in. Approximately half of their length should stick out. The chamfered end of the tube must be facing out!!!!
Slide on the front-PTFE-holder, note the upper circular openings are for the tubes.
Secure the front-PTFE-holder using four M3x10 screws.

Step 15 Selector-finda assembly (part 1)

Selector-finda assembly (part 1)
Selector-finda assembly (part 1)
Selector-finda assembly (part 1)
Selector-finda assembly (part 1)
Insert three M3nS nuts in the selector-finda body, all the way in. Ensure alignment with the 1.5mm Allen key.
Slide in the M3n nut. If possible use long screw from the "Spare" bag or from your MK3 kit. Press the nut in using hand, hammer shouldn't be necessary.
Insert remaining three M3nS nuts in the selector-finda body, all the way in. Ensure alignment with the 1.5mm Allen key.

Step 16 Selector-finda assembly (part 2)

Selector-finda assembly (part 2)
Selector-finda assembly (part 2)
Selector-finda assembly (part 2)
Rotate the selector-finda as in the picture. Holes for the tubes are bigger from this side.
Insert the tubes all the way in. Both should be aligned with the surface of the printed part.
In case you can't push the tubes in, try first rotating the tube while pushing down. Then turn the printed part and a use flat surface to push the tubes in evenly. Avoid using hammer as you can damage the tube's rim!

Step 17 Selector motor parts preparation

Selector motor parts preparation
Selector motor parts preparation
Selector motor parts preparation
Selector motor parts preparation
For the following steps, please prepare:
mmu2-selector-front-plate (1x)
M3x10 screw (7x)
Smooth rod 5x120sh 120 mm (2x)
Selector motor (1x)
Lead screw nut (1x)
The nut is on the motor, take it off the lead screw.

Step 18 Nut assembly

Nut assembly
Nut assembly
Nut assembly
Nut assembly
Rotate the selector-finda as in the picture. There is a cut out for the nut.
Place the nut on the selector-finda part, it should fit in the cut out.
Secure the nut with two M3x10 screws.
There are four holes in the nut, you can use any of them, they are the same.
Tip: if you can't reach the M3n nut, use a M3x18 screw from the spare bag and by tightening it, pull the nut closer.

Step 19 Selector-front-plate assembly

Selector-front-plate assembly
Selector-front-plate assembly
Selector-front-plate assembly
Rotate the selector-finda as in the picture.
Place the selector-front-plate as in the picture. Note, there is a flat and angled edge on this printed part. The angled edge should point toward the centre of the selector-finda body.
Secure it with two M3x10 screws.
In the next step we will assemble the blade, but keep the parts you have prepared at step 17, we will use them soon.

Step 20 Blade-holder parts preparation

Blade-holder parts preparation
Blade-holder parts preparation
!!! WARNING: in this and following steps you will be assembling the blade. Make sure you don't cut yourself. Use pliers or gloves to protect your fingers !!!
For the following steps, please prepare:
mmu2-blade-holder (1x)
M3x10 screw (2x)
blade (1x)
There are two blades in the kit, the other one is a spare.

Step 21 Blade-holder assembly

Blade-holder assembly
Blade-holder assembly
Blade-holder assembly
Blade-holder assembly
Prepare the selector-finda part as in the picture.
Carefully place the blade in the prepared cutout and align it with the top left corner.
Make sure the sharp part of the blade is pointing in the indicated direction.
Note that the blade-holder printed part has protrusion in the shape of the blade, place it on the top of the blade and make sure that both parts are properly aligned.
Place the blade-holder on the top of the blade and secure it with two M3x10 screws. Before you tighten the screws fully, ensure the blade is seated properly. Gently push it with the Allen key.
From now on pay attention while handling this part. The blade sticks out and you can cut yourself!

Step 22 Selector motor assembly (part 1)

Selector motor assembly (part 1)
Selector motor assembly (part 1)
Selector motor assembly (part 1)
Selector motor assembly (part 1)
Before assembling the motor we need to assemble the selector-finda part.
Place the selector-finda part as in the picture. Important is correct orientation, exact position doesn't matter now.
Insert both shafts through the pulley-body and the selector-finda part.
Make sure both shaft reached the end of the pulley-body. There are two circular holes for them.
Ensure the shafts are aligned with the pulley-body and move the selector-finda all the way to the left.
FINAL CHECK: move the selector back and forth along the entire length of the smooth rods to ensure the blade isn't colliding with the other printed parts.

Step 23 Selector motor assembly (part 2)

Selector motor assembly (part 2)
Selector motor assembly (part 2)
Selector motor assembly (part 2)
Selector motor assembly (part 2)
Slide the Selector motor in, make sure the cable points up.
Check the thread on the shaft and ensure there is no piece of plastic in it. Otherwise, you might have issues with the assembly.
As soon as you reach the thread of the nut, hold the selector-finda and start rotating the shaft clock wise.
Rotate with the shaft until the motor touches the pulley body. Make sure the selector-finda is all the way to the left.
Secure the Selector motor using three M3x10 screws.

Step 24 SuperFINDA sensor parts preparation

SuperFINDA sensor parts preparation
SuperFINDA sensor parts preparation
Though the design is similar, please note there is P.I.N.D.A. or SuperPINDA probe used in the extruder on a regular Original Prusa i3 printer and F.I.N.D.A. or SuperFINDA sensor, which has a shorter cable and is used only in the MMU unit.
For the following steps, please prepare:
SuperFINDA sensor (1x)
F.I.N.D.A. ball (1x)
M3x10 screw (1x)
Extra ball is in the spare package ;)

Step 25 SuperFINDA sensor assembly

SuperFINDA sensor assembly
SuperFINDA sensor assembly
SuperFINDA sensor assembly
SuperFINDA sensor assembly
Push the ball in the selector-finda circular opening.
Carefully screw in the SuperFINDA sensor. We recommend wrapping the cable as in the picture to avoid damaging it.
The exact position of the SuperFINDA sensor will be calibrated in the upcoming chapter. For now, let about 15 mm (0.6 inch) of the metal part above the printed part.
The newest MMU2S unit revision has inspection windows on the sides of the selector. It is a good starting point to line up the bottom of the SuperFINDA probe exactly with the top of the inspection window when looking from the selector motor side.
Insert M3x10 screw as in the picture, tighten it very slightly.

Step 26 MMU2 unit parts preparation

MMU2 unit parts preparation
MMU2 unit parts preparation
For the following steps, please prepare:
Shaft 5x16sh (2x)
625 bearing (2x)
M3x10 screw (2x)
The MMU2 unit is considered as the set of all the printed parts, motors, shafts, etc. assembled together.

Step 27 MMU2 unit assembly (part 1)

MMU2 unit assembly (part 1)
MMU2 unit assembly (part 1)
MMU2 unit assembly (part 1)
Turn the pulley-body side without motors towards you.
Push the bearing in. Make sure it is aligned with the pulley-body.
If the bearing can't be pushed in easily, check the circular opening in the pulley-body and clean up any print imperfections if neccessary.

Step 28 MMU2 unit assembly (part 2)

MMU2 unit assembly (part 2)
MMU2 unit assembly (part 2)
MMU2 unit assembly (part 2)
Turn the pulley-body side with motors towards you.
Push the bearing in. Make sure it is aligned with the pulley-body.

Step 29 MMU2S unit assembly (part 3)

MMU2S unit assembly (part 3)
MMU2S unit assembly (part 3)
MMU2S unit assembly (part 3)
Let's assemble the MMU2S unit ;)
Prepare the pulley-body and idler-body as in the picture. Note position of the motors.
"Rotate" the idler-body on the pulley body.
Proper alignment will be done in the next step.

Step 30 MMU2 unit assembly (part 4)

MMU2 unit assembly (part 4)
MMU2 unit assembly (part 4)
MMU2 unit assembly (part 4)
Turn the side with two motors towards you.
Slide in the shaft 5x16sh, align it with the outer surface.
Turn the side with one motor towards you.
Slide in the second shaft 5x16sh, align it with the outer surface.

Step 31 MMU2 unit assembly (part 5)

MMU2 unit assembly (part 5)
MMU2 unit assembly (part 5)
MMU2 unit assembly (part 5)
Turn the side with two motors towards you.
Use M3x10 screw to secure the shaft against falling out. Tighten the screw to the surface of the printed part.
Turn the side with one motor towards you.
Use second M3x10 screw to secure the shaft against falling out. Tighten the screw to the surface of the printed part.

Step 33 Tensioning system assembly

Tensioning system assembly
Tensioning system assembly
Tensioning system assembly
Slide the springs on the screws.
Insert screws with the springs in the holes on idler-body.
Tighten the screw heads slightly below the surface of the printed part.

Step 34 It's Haribo time!

It's Haribo time!
It's Haribo time!
Quite challenging chapter, wasn't it?
Pulley body assembly required your attention, eat no less than 20 % of all bears.

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