Base gearing

My base is currently 4 x 4" omni-wheels driven by 4 Turbo geared motors, with the back wheels driven directly onto the motors, and the front driven by 4 60 tooth gears to move the motors to the back of the base, out of the way.

Technically the speed of the wheels will not change with the gears as there is a 1:1 ratio on it.
The back wheel is also able to have another 60 tooth gear put on it to join them all up.

I have a few choices that i’m tossing up on with gearing.

  1. I leave it as it is, with an encoder on each wheel and suffer from front wheels maybe burning out under heavy load (i doubt this will happen as it is an all aluminium bot).
    the drawback with this is that we have 12 motors total and need to Y-Cable something so I was thinking just Y-cable each side of the base and leave it at that. Which leads me to my next point.

  2. If i’m going to Y-Cable them together anyways i may as well join up all the wheels with gears to spread the load of the 2 motors around and just use one encoder on each side. If I’m going to do that then I may as well add another wheel in the middle which may help with weight distribution.

  3. I leave it as it is and Y-Cable another 2 sets of 2 motors somewhere else.

Which to choose?
Is there actually any benefit of having 4 encoders as opposed to 2 (I know it shouldn’t but it may have some other usage I’m not aware of)


I would gear all of the wheels together, use two y cables, and use two encoders. You can add another wheel in the middle if you want.

If you’re using 5 gears to distance motor and wheel, you should chain them instead.

We have a six wheel drive with the back four direct driven. The turning radius is within 3 inches, and the motors are in a nice place.

How are your front 2 wheels driven? By chain or are just there to free rotate?

The front 2 wheels rotate freely

Does that make a difference in it’s driving ability?

We ran this configuration at our states. We were one of the most nimble robots there, and our driver didn’t notice any difference.