Just a quick and easy pinion gear holder. It is for 3.18mm shaft size pinions like for most 1/10 r/c cars. Use some rubber bands or velcro straps to hold the cover on. The dummy pinion gear is optional. I would suggest an infill setting of 50% or more just for the strength of the shafts. The cover will help with the overall strength>
There might need to be a bit of sanding on the shafts for the pinion to slide on easier.