pic: 3 CIM WCD Crazy Geabox

[asid61]

Originally Posted by Knufire

I would be wary of double loading the CIM pinion like that.

That's not a cim shaft, that's a regular 3/8" hex shaft.

You're really starting to push the envelope for these sorts of gearboxes, but there is a limit and you've reached it. Now the weight of your box is becoming almost solely dependent on how well you lighten the plates and gears; each new design has to have a certain minimum of gears in it to work.
Have you tried a different design like with belts?