PRINT THE GEARS WHIT SUPPORTS!!
What You need:
x4 ball bearing 5x6x14
x10 M2 screws
x2 M2 nut
5mm axel to insert the gear
you have to install the gear and move it for around 5 minutes to make them move very smooth, after that put some grase to be sure of eliminate the friction.
The holes for the motor are at 32mm for 1/8 motor or whatever you want.
The file are f3d (fusion 360).
print the gears whit the supports