Modified adapter-printer to fix filament detection problem in MK3S+

This modified adapter-printer part changes the position of the steel ball in the filament sensor of the MK3S+ to fix detection problems.

Background

I was having failed detections with TPU filament because it was slightly compressed by the force of the magnets in the FS-lever, which resulted in the FS-lever not being in the correct position for the IR-sensor to detect.

I observed that the FS-lever appeared slightly worn (<1mm) where the ball was making contact, and that the ball was no longer aligned with the centre of the FS-lever arm.

Rather than reprint the FS-lever arm (which required black PETG that I didn't have on hand, an additional screw, and moving a magnet), I decided to redesign the adapter-printer part and raise the ball by 1.6mm.

This corrected the issue for me. You can see the original part (black) and my new part (orange) side by side in the attached picture.

Printing instructions

• Print the .stl file as oriented.
• I used 0.15mm layer height with 40% gyroid infill, but I'm sure the Prusa recommendation of 0.2mm default settings would be fine.

Installation instructions

Please refer to these documents on Prusa's support site that describe how to access the adapter-printer part within the extruder and assemble it:

• https://help.prusa3d.com/article/ir-filament-sensor-troubleshooting-mk2-5s-mk3s_112226
• https://help.prusa3d.com/guide/5-e-axis-assembly_169235#169584