CoreOne+ INDX Spool Holder Mounts Optimized for 3D Printing

If you purchased the 4-tool upgrade kit, intending to later upgrade to the 8-tool version, consider attaching 4 additional spool holders on the right side when installing the 4-tool upgrade (at least the mounting plates and universal pucks).  This will reduce the disassembly/reassembly effort when upgrading to 8-tools since much of that area is already disassembled when installing the 4-tool upgrade.

There is just one problem with that approach…those parts provided by Prusa are injection molded.  Prusa provides a 3D-printable model for the pucks, but they currently don’t have a model for the mounting plate.

These models were created using precise measurements of the enclosure CAD model, the universal puck model, and the physical injection-molded mounting plates.  The hole sizes and spacing in these models are dimensionally accurate (making them drop-in replacements); the outer perimeter (which is not critical) is not exact, but the difference is no more than 0.5mm.

Making printer-friendly models necessitated making separate left and right versions.  The mounting positions for each plate are embossed on their back surfaces.  Unnecessary features have been removed, and the counter-sunk surfaces for screw heads on the back are stepped for clean printing without supports; the steps are 0.2mm, so use 0.2mm layer height for the print.  The mounting plate models are compatible with both 3D printed pucks, or injection-molded pucks (which have additional tabs on the back).  Photos of the 3D printed and injection-molded parts are included for comparison.  A ridge has been added to the top surface to help align the puck while starting the screws.

I was unable to find a source for the M3x12rT (Torx head, thread-forming) screws that are used by Prusa for attaching the puck to the mounting plate.  I used these M3 self-tapping screws from Amazon: “M3 Self Tapping Screws, Hex Socket Cap Head Assortment Kit”.  Their tips are more tapered than those used by Prusa, so it is recommend to use 14mm or 16mm length to capture a couple more threads (longer than 16mm will only work with the injection-molded puck, not the 3D printed puck version).

Design Features:

• No supports required

• Drop-in replacement for the original puck mounting plates

• Works with both the printed and injection-molded universal pucks

• Integrated ridge to assist with alignment when starting the screws

• Counter-sunk holes for the screw heads on the bottom surface have have stepped surfaces to produce smooth holes (no post-print cleanup)

• Each plate is labeled by position, and can only be assembled one way (minimizes confusion)

Parts Required:

• 4 self-tapping M3 screws per mounting plate for attaching the universal puck.

Printing Notes:

• Print using a 0.4mm nozzle, 0.2mm layer height, structural, with 20% gyroid infill.

• Use a strong, rigid material like PC-CF.

• Please DO NOT use the .bgcode file that has been provided (always slice your own files for your specific printer, filament, environment, etc.).  The file was only included to provide a reference for approximate print time.

Assembly Instructions:

Follow the instructions from Prusa for the assembling the mounting plate and universal puck, and attaching the assembly to the printer frame.