generic gearbox / transmission

This is a tiny redesign of my last semesters work at university. It is made to be printed on a 200x200 surface under use of standard parts:
Attention: clearances for merging parts aren't included yet. This will follow in a few weeks when I test it on my printer.

Parts needed:
• 2*fether keys 5x5x18 DIN 6885 FORM A
• 4*ball bearings 16002 SKF 15x32x8
• 2*circlips DIN 471 18x1
• 4*circlips DIN 471 15x1
• 1*valve screw (or a closed casing) DIN 908 10X1
• 4*o-ring seal OR2002900-E7 (https://www.tss.trelleborg.com/ecatalog/products/o-rings/OR2002900-E7.html?ref=search)
If you prefer to print your standard parts, please find their STLs here by yourself: This is due to copyright issues: https://www.traceparts.com

to be continued with:
• new key mechanism for the small gear (possibly multiple)
• clearances and assembly instructions
• max torque allowance