Spool bearing 44mm/84mm

thingiverse

I took on the challenge of designing a working bearing as a way to practice my skills and ended up with a perfectly adequate spool bearing in the end. After about 36 hours of thought, I lifted a working bearing off the bed after several failed attempts. It took me six bad designs using CAD before the seventh one was good enough to print all the way through. My printer settings got it right when the model had a horizontal radial gap of .35mm on the vertical part and about .50mm on the part with a 60-degree overhang where the rolling pin meets the rings. The bearing has an inner diameter of 42mm and an outer diameter of 84mm to fit my filament spool and axel of the machine's holder. The height is 15mm, although I tried to get everything to fit in 10mm - unfortunately, that didn't work out. However, I still managed to leave plenty of free space around the axel while trying to make the bearing both functional and as small as possible with my present skills and available time. With this design, I'm very satisfied with the result as my first totally self-designed bearing from scratch. With more time for test prints, I believe I could tweak this design to be even smaller. As seen in the ready bearing, there's almost enough space to fit a 14th pin with these outer and inner diameters - it would take slimming down the pin by about .1mm-.2mm, but then the gap wouldn't be the same. I'm not great at parametric designing yet, but I'd like to think that thirteen is still a good number for the bearing to hold together. I'm happy not to be overly superstitious!