Planetary 4:1 DC motor gearbox

Hi,
this is a universal 4:1 reduction gearbox I designed. It can mounted in line with any standard small sized DC motor.
The maximum allowed distance of the retention screws (on the front side of the housing of the motor) is 23mm.
I made two different sun gears in order to accept 2mm and 3mm shafts.
The output power is transmitted through a 5mm hexagonal hole.
I designed the fits for the moving parts with a clearance of 0,2-0.3mm, so printers with low accuracy can print it.
Additional g