the motor has so huge diameter that i am able to fit only 18T pinion
i need to use also 16T and 14T but cant position the motor as it already touches the transmition and cant move any further.
for 16T i need to move the pinion closer to the spur about 1mm and for 14T 2mm
any advice?
i am thinking of sanding the transmition case but dont think that I can take 2mm out of it
18T

14T

motor