pic: Planetary...Wheel?

[Joe Johnson]

What is the purpose of the design?

It is fairly clever but without knowing what you are planning it is hard to be fair.

In generally 3 things worry me.

Others have said it already but imho, you need to get independent bearings on the wheel/sun. Gears are not intended to be bearings. You have little chance of success if you depend on the gears for support.

The thinness of the wheel. I think you will want to consider thickening up the wheel. Wheels take considerable side loads, more than I would expect a 10" dia, 1/4th thick spoke splate to be able to support.


Finally, gear tooth face width. This is 2 problems in one. I think 1/8th thick gears will be hard to keep aligned.

Without actually counting teeth it looks like you've got about a 15:1 overall reduction from the motor to the wheel. But more importantly, 2 Chiaphua motors put out a lot of torque, more than those gears look like they can hold if my gut is right.

Without actually doing the calculations to see if they are going to fail, you can get a feel for things by looking at designs you know work.

Without actually counting teeth it looks like you've got about a 15:1 overall reduction from the motor to the wheel. Thinks about it this way: Look at the face width of the gears inside a planetary gearbox. Take the Dewalt for example. Look at the 2nd stage. See how thick those gears are? Well, your ratio about the same as that second stage BUT BUT BUT... ...2 Chiaphua motors will put out 5-10 times as much torque as a single drill motor. So... you've got many times the torque trying to be supported by gears many times thinner. Something has got to give.

Just some things to think about.

Joe J.