MMU2/3 assembly guide on Prusabox

Assembly time: 60 min

Required elements:

  • PrusaBox
  • MMU2/3
  • 10pcs M3 square nuts
  • 12pcs M3*6 screws
  • 6pcs M3*10 screws
  • 1pc M3*12 screw
  • 2pcs M3*18 screws

Printed parts available in download section

Parts overview

Step 1 Disassemble MMU2/3 brackets

mmu disassembly
SWOOEpUqRqjP4apl
mmu-disassembly_3
mmu disassembly SWOOEpUqRqjP4apl mmu-disassembly_3

Unscrew the 4 x m3 screws to remove the original bracket

Unscrew 2 x m3 screws to disassemble the electronic mmu board cover.

Disconnect the pulley motor (yellow) and the selector motor (red) and add one or two cable extender.

Depending on your MMU version, motor cable won’t have the same length. Cable extender is not always required for both motors.

Step 2 Doors

1-mmu assembly
2-mmu assembly
1-mmu assembly 2-mmu assembly

Files in 01_Doors_hinges_lock_handles folder:

2*01_top_door_handle

Insert M3 nuts into each slots of handles

Remove plastic protection from both sides of each plexiglas doors

Position handles on top of the translucent doors. Make sure they are oriented like the picture

Screw handles from under, with 4 M3*6 screws

Step 3 Printed parts assembly

3-mmu assembly
4-mmu assembly
5-mmu assembly
3-mmu assembly 4-mmu assembly 5-mmu assembly

Files in 15_MMU_integration folder:

15_cover_front

15_cover_middle

15_frame_right

15_frame_left

Insert M3 nuts into each slots

Assemble the middle cover with the two frames, use 4 M3*10 screws

Assemble the front cover with the two frames, use 2 M3*10 screws

Step 4 Slider assembly

6-mmu assembly
7-mmu assembly
8-mmu assembly
6-mmu assembly 7-mmu assembly 8-mmu assembly

Files in 15_MMU_integration folder:

15_slider

Screw half-way a M3*12 screw as in the picture

Insert both parts of the sliders inside the frames

You can close the sliders and the front cover. The slider will follow MMU’s movements, while keeping the enclosure closed. It should move freely. Depending on the print quality, you might have to trim the long edges.

Step 5 Install MMU2/3 on frame

9-mmu assembly
10-mmu assembly
11-mmu assembly
9-mmu assembly 10-mmu assembly 11-mmu assembly

Files in 15_MMU_integration folder:

15_cover_back

Install MMU2/3 unit on the frame

Screw using screws that you remove on step 1

Add the back cover with 2 M3*6 screws

Step 6 Electronic board assembly

12-mmu assembly
13-mmu assembly
12-mmu assembly 13-mmu assembly

Files in 15_MMU_integration folder:

15_board_cover_mmu_version

15_board_spacer

The cover for the electronic board is the same as the original. But we designed a file that can be printed in two colors using MMU

Insert M3 nuts into each slots

Assemble both parts using M3*18 screws. Make sure you wire the cables as in the picture.

Depending on your version of MMU, you may need to add one or two of the motor cable extenders.

Step 7 Assembly on PrusaBox

14-mmu assembly
15-mmu assembly
16-mmu assembly
17-mmu assembly
18-mmu assembly
14-mmu assembly 15-mmu assembly 16-mmu assembly 17-mmu assembly 18-mmu assembly

Files in 15_MMU_integration folder:

3* 15_top_door_plot

Install the 3 blocks as shown in the picture, using M3*6 screws

Install the electronic board with a M3*6 screw, but don’t tighten too much as the left door will go between the printed part and the metal frame

Install the MMU unit on the PrusaBox. Use M3*6 screws at the back

Insert PTFE tubes you got with your MMU, and install the doors

Insert PTFE tube between the extruder end the MMU, that should go through the hole in between the two parts of the slider

The PTFE should be long enough for the extruder to reach the X axis left and right extremities when it is in the lower Z axis position.

Step 8 Secure motor cable

Use zip tie to secure motor cable on the back over of the mmu2/3 frame part, and to secure the cables along the printer frame through it’s way to the main board.