INBXX Roller and PTFE 2020 Spacers (for SpoolRoller Configs)

INBXX Roller and PTFE Spacers (for SpoolRoller Configs)

Not all of my t-nuts holding the Rods and PTFE mounts are completely secure. Some of them may end up moving a little during active use and modifications of INBXX, so I wanted something that would take up the remaining slack space along the extrusion bar to keep things from moving.

These spacers are easy to print, no supports (15% infill, 0.20mm SPEED, PETG/ASA), and snap into place along the 2020 channel. The 3MF file is included so making any changes (Core One L version, different # of PTFE Mounts) to fit your needs is as simple as changing the widths as needed.

To install, slightly loosen the screws to the mounts to be able to make room. Place the appropriate piece over the channel, and firmly press down until it snaps in place. Move the mount up to the newly inserted piece, and continue adding the next piece. Once all pieces for the bar are in place, tighten the screws to the existing mounts.

The installation method is the same for all versions, but some design considerations are made due to the 90 degree connector on the double INBXX being in the way.  Each spacer should butt against the Mounts, and the non-tabbed end against opposite ends.

For the Rod Mounts, the INBXX instructions give guidance for the distance between the two Roller Mounts to be about 110mm, which is the same length as the Middle Roller Spacer. For the Front Roller Spacer, I have it set to be 33mm, so that the front roller bar is a few millimeters away from the PTFE Mounts per INBXX instructions. If the entire set doesn't fit, I would suggest adjusting the Rear (or L&R for PTFE) by 1mm (part named "Body ###mm" on the X axis) if needed.

For the PTFE Mounts, the file includes a 4, 1 pound PTFE roller set up on plate 2. If you have a different configuration, the widths are easy to change once you know what the widths between the mounts are. Additional information below for alternative configurations.

The extrusion bar length for Core One version of INBXX is 350mm. Each PTFE Mount is approximately 25mm wide. Take the number of PTFE Mounts and multiply by 25, and subtract that number from 350. That leaves figuring out the widths in between mounts and the ends. Measure the space between one mount, and multiply that by how many spacers you need (2 mounts=1 spacer, 3 mounts=2, 4 mounts=3, 5 mounts=4) and subtract that from the total. Whatever you're left with, divide by 2 for the end pieces.

Ex: 4 mounts, so

=350mm total length - (4 mounts x 25mm apx mount width)

=350mm-(4x25mm)

=350mm-(100mm)

=250mm is the total spacer length needed

I measured the space between one mount to be 62mm, with 3 spaces total

=250mm - (62mm * 3 spaces)

=250mm - (186mm)

=74mm remaining length

What's remaining is for the left and right end pieces, so divide by 2

=74mm / 2

=32mm (per side)

So print 3@62mm in between pieces and 2@32mm end pieces for 4 PTFE mounts.