PRUSA MMU3 unit flippable mount on CoreOne, no drill no cut

Back Ground

  I have a MMU3 and I bought a CoreOne printer. But I am too cheap to buy the MMU3 to CoreOne upgrade kit/parts.

so I made this to mount the MMU3 on CoreOne top.

Features:

1. Keep the original CoreOne top panel, no cut no drill.

2. MMU3 unit can flip back and forth, so the top panel can be easily removed.

3. Use a shorter vent cover/grid, so to use existing 4 holes to let PTFE tube pass through.

4. Push the ptfe tube to front to easily move it, no other locking mechanism needed.

5. Use a lock pin to lock the MMU3 in place.

6. Vent Grid is a large part, but now it's slightly shorter so core one can print.

Hardware needed:

For Flippable Mount

1. M3 heat insert ( 3-4-5 ,  m3, 4mm height, 5mm other diameter) ,  put it on inner mount plate

2. M3 20mm Hex socket head screw 20mm flip hing X 2 

3. M3 nylon lock nut X2 , put in inside outter_mount_baseoutter_mount_base

4. M3 20mm black hex socket head screw, black type we can use magnet to attract it better, put it through the lock pin part.

5. round magnet 6 dia X 3mm thick, optional, so we can use magnet to keep lockpin in place

6. M3 10mm X 4  hex socket head screw to mount MMU3 on hing part A B

7. 8mm dia 2mm thick round soft silicon pad (6mm should work as well )

PTFE pass through and vent grid

M3 Hex socket head screw 10mm  X2

M3 heat insert ( 3-4-5 ,  m3, 4mm height, 5mm other diameter) ,  put it on inner ptfe bottom.

Print Settings

1. print all parts using PETG or other

2. recommend orange to match prusa style or black to match coreone outer case metal color

3. 30% infill and 4 parameter

Install Steps

1. put heat insert X 2 into inner_mount_plateinner_mount_plate, insert from the larger hole 

2. put nylon lock nut X 2 into outter_mount_base hinge hole X 2

3. put one round magnet 6X3 in one of the outter_mount_base by the nylon lock nut, can choose right side or left side

4. install the outter mount plate on coreone outside, put inner mount plate inside CoreOne, use M3X10 2pcs to lock these two parts in place.

5. install hinge A B on bottom of MMU3, using 4XM3 10mm. note the direction.  socket head hole should face out side, the word “IN” should face inner side, two a square pattern opening should be facing each other.

6. use 2X  M3 20mm to mount the mmu3 unit and hinge to the base.

7. insert a black screw M3 20mm into lockpin part,  put lock pin to secure the hinge part in place.

8. put 3X silicon pad on outer mount base, so when MMU3 flip back too hard, it won't cause damage.

9. put one silicon pad on each hinge bottom ( where it touches the top panel)

Warning:

when lock pin is not in place, if you lift the panel, the MMU3 could flip backward and hit the mount base hard, since MMU3 is quite heavy.   

even though we have  3X soft silicon pad to reduce the impact, this should be avoided

Put 2 heat insert to ptfe pass through part bottom.

install it on top panel.

Optional:

ptfe_fitting_shorterptfe_fitting_shorter

put it on NexTruder's input PTFE fitting

Update 2026 Jan 02

Since PRUSA released the CAD file of the COREONE printer, so I can make a better Vent Cover.

it now can fully cover all the vent holes.

improvements: no gap, also cover the screw 3rd hole