This is the first design I am trying out. There already is a generator alredy online but it is just not there yet.

The gear box will be build from laminated layers starting at the bottom with the plate for mounting the motor. On top of that are rings and ring gears housing the planet carrier made out of two disks connected with walls by finger joints.

There will be two possible top sections: One for driving a belt which has a pulley directly on the planet carrier that is supported on top by a ball bearing:

The second variant will have a plate with one or two bearing that the drive shaft passes through. My idea is to use a hex bolt who's head is pressed into the planet carrier.

It should be easy to create multiple stage gear boxes by just adding more ring gears and dropping in planet carriers with a sun gear on top.