608 Bearing Airsoft 6mm

thingiverse

I wanted to design a more rounded bearing model instead of the typical blockier 608 airsoft bearings available. I created this design in just five minutes using Fusion 360. The bearing features a 4 mm center shaft and has a 6mm vertical bore diameter, with most of it cut out. The horizontal bore diameter is 6.1 mm. To account for manufacturing tolerances, I added an extra .05 mm to each inner and outer bearing's horizontal diameter. To make assembly easier, I pre-selected seven Airsoft BBs with diameters around 5.842 mm. If you prefer tighter tolerances, try using slightly larger BBs instead. After experimenting with various sizes and ratios, I decided on this tolerance level for optimal low rotation resistance and minimal movement freedom. The design provided the best outer bearing spin times when the horizontal bore diameter was 6.2 mm (.1 mm added to each bearing for a wider channel). However, this resulted in a very loose fit that wasn't necessary for my application (filament axle spindles). For slightly looser tolerances and better pre-breakin spin time, consider checking out thingiverse's #2229433 design.