40x137mm Lawnmower wheel, 608 skateboard bearings, m8 axle

thingiverse

This is a wheel I designed as a replacement for my lawnmower, where the original has too much friction and a bad way of fixing it, so it kept getting loose. Might be useful for other projects too. It needs two 608 bearings and 8mm bolt of suficient length. It has a spacer, that you can print separately, as to keep the pressure from tightening the screw away from the bearings, but keep in mind that the plastic you're screwing against might yield. I used a regular hex nut to distance the wheel from the frame. Printing is pretty straightforward, I used a 0.6mm nozzle, 0.8mm extrusion width, 0.4mm layer height. Uses about 100g of filament per wheel. There is a calibration piece you can use go get your fit right, so the bearings fit well. I used random z-seam alignment do spread impecision and weak spots over the entire ring.