Bakflip Tonneau Mounting Knob

I went to turn the mounting knobs for my Bakflip FiberMax tonneau cover for the first time in a while, and the cylindrical part of the knob that holds the threaded nut completely disintegrated with no force at all. Both knobs just fell apart in my hand when I tried to turn them. Not sure what kind of cheap plastic the manufacturer must have used, because these things don't even see direct sunlight. Naturally, I got to work and modeled my own replacement.

This is a replacement part for the two main knobs on the underside of the Bakflip FiberMax hard folding tonneau cover, which hold the cover to the bed rails. Odds are good that this part is the same on other folding Bakflip covers (MX4, G2), as it looks like they all use the same basic design and mounting system.

The fit for the nut is modeled as a PRESS FIT. As in, I had to use a bench vise to press the nut into the knob. It went in easily with the vise once the nut was aligned with the hole, but provides a very secure hold.

The tolerances for the nut may vary depending on the filament you use and your printer's calibration, so I've also included the STEP file.

Print with LOTS OF PERIMETERS. I printed with a 0.6mm nozzle, 40% Gyroid infill, 0.25mm layer height, 6 perimeters, and 4 top & bottom solid layers. If the cylindrical portion is 100% perimeters when sliced, then you're using enough perimeters. No supports needed.

I used Polymaker Tough PLA, but time will tell how it holds up in the Summer heat. Plain old PETG might be a bit too brittle.