Update 2024-05-25 - [rear-axis - A2212]: Moved the screw hole on the axle by 1.75mm instead of .8mm to have more space between the motor screws and the gear.
Update 2024-05-26 - [rear-axis may2024 update - a2212]: The original rear-axis got updated to include nuts and different wheel-adapters. I added the new axis with the adjusted screw hole.
To use this you have to modify your motor. Remove the e-clip and the grub screw holding the motor shaft. Pull the motor apart and push the shaft all the way through. You could also turn the shaft around with the e-clip on the other side but I just dremel'ed a flat spot on each end of the shaft, one for the grub screw and one for the pinion.
rear-axis - A2212 is kinda optional since I only moved the screw hole by 0.8mm to align the gears. This remix works without the modified axis but the gears don't align fully.
The author remixed this model.
The plan was to just modify rear-frame-r but the original pinion wouldn't fit so I changed that and then the pinion had to be pushed so far in that it would hit the screws so I modified rear-axis aswell.