Prusa Core One/+ MMU3 Buffer

In my 3D setup, the filaments are enclosed in airtight containers placed on a shelf above the printers. In this context, it's necessary for the MMU3 buffer to be connected to these overhead containers; this allows me to use the MMU3 in a minimal footprint. This is why I chose the same MMU3 buffer configuration as the one I had set up on my previous MK4S printers.

See my solution for installing the MMU3 on the PRUSA CORE ONE .

Inspired by @Martin_J_6129's buffer model , I had to completely redesign it to make it compatible with the CORE ONE. I particularly took into account the fact that the PTFE tube connecting the MMU3 to the Nextruder is much longer (710mm instead of 360mm for the MK4S). This buffer is therefore deeper to accommodate a longer filament length in the parking position. Finally, I designed a mounting system that uses the existing holes in the CORE ONE's structure.

A. FRONTAL SLOT ASSEMBLY

There are two frontal slot models : - Model with a separate number for different colors; the slot and the number are printed separately. The numbers are attached with a simple dot of glue. - Model with raised number Choose the one you prefer :) In both cases, the assembly is the same.

ASSEMBLY

Prepare accessories: - 10 x PC4-M6 fittings - PTFE tubing - For each "PrusaCoreOne_MB_PTFE_Guide" (Front and Back): - 2 x M3x8mm SHCS screws - 2 x M3 nuts 1. Screw a PC4-M6 fitting onto each end of a slot. The holes are not threaded, but the screws will grip the plastic. Tighten until contact is reached. 2. Insert “PrusaCoreOne_MB_Fslot_Handle” in the front side of the slot. 3. Secure “PrusaCoreOne_MB_Fslot_Handle” inserting “PrusaCoreOne_MB_Fslot_HandlePin” on the back side. 4. On the side of the slot connected to the MMU3, connect a PTFE tube with a length of 60cm to 70cm. 5. On the other side of the slot (filament inlet), connect a PTFE tube of a length of your choice. 6. To keep the PTFE tubes parallel between the buffer and the MMU3 you can install one or more "PrusaCoreOne_MB_PTFE_Guide" (Front and Back) assembled with two 3x8mm SHCS screws and two M3 nuts.

B. BUFFER ASSEMBLY (look at the numbered photos)

Prepare accessories: - 4 x M3x12mm SHCS screws - 3 x M3x14mm SHCS screws - 7 x M3 lock nuts - 4 x M3x30mm SHCS screws - 2 x M2x6mm SHCS screws 1. Remove the three plastic clips on the back of the right acrylic side plate. 2. Lower the plate as far as it will go and move the Nextruder all the way to the left. Secure "PrusaCoreOne_MB_Holder" with three M3x14mm SHCS screws and three M3 lock nuts. 3. Secure "PrusaCoreOne_MB_BodyBack" (it doesn't go in the right direction) to "PrusaCoreOne_MB_BodyFront" with four M3x12mm SHCS screws and four M3 lock nuts. 4. Insert the six "PrusaCoreOne_MB_DividerShort" into the rails, with the large chamfer facing the bottom of the buffer. 5. Insert the six "PrusaCoreOne_MB_DividerLarge" into the rails, with the large chamfer facing the front of the buffer. 6. Attach the "PrusaCoreOne_MB_FrontLeft" and two "PrusaCoreOne_MB_Side" (they are the same) to the front left side of the buffer with two M3x30mm SHCS screws. Do not overtighten to allow the two "PrusaCoreOne_MB_Side" to pivot freely. 7. Attach the "PrusaCoreOne_MB_FrontRight" to the front right side of the buffer with two M3x30mm SHCS screws. Do not overtighten to allow the two "PrusaCoreOne_MB_Side" to pivot freely. 8. Secure the two PrusaCoreOne_MB_Sides with two M3x6mm SHCS nuts; the two PrusaCoreOne_MB_Sides can no longer rotate. 9. Insert the buffer onto the PrusaCoreOne_MB_Holder, aligning the dovetails. 10. Insert the five PrusaCoreOne_MB_Fslot_Body_X nuts (1 to 5) into the buffer.