Using Modkit to Program Omni Wheels and Rubber Wheels

We would like to program two 250mm wheels with two omni wheels for our drive train. Modkit drivetrain programming does not allow us to configure the drive train this way. It defaults to all rubber wheels or all omni wheels. How can we get around this and program it to be 2 of each?Is there a detailed Modkit programming resource we can purchase or access? Everything we find online so far is very basic. We would like to learn more in-depth programming with ModKit and do not have the resources at our school.

Unofficial response…

The Modkit drivetrain feature only supports what I would call ‘standard’ drivetrains. It does support omni wheels on the front or back, and then 200mm rubber wheels on the other end. The reason that it does not support 250mm wheels + omnis (or 250mm + any other type of wheel), is that different size wheels would move at different speeds.

If you wanted to build a robot with 250mm on one end, then you would have different gearing for the different wheel sizes, so that the front and back wheels moved at the same speed.

However, if you are only powering the 250mm wheels then you could have omnis on the other end without having to worry about gear ratios. In Modkit you would just configure your drivetrain to use all 250mm wheels. By only powering the 250mm wheels, I mean you have Motor Layout that did not have 4 motors and the Wheel Grouping would be set to ‘Separate’.

Here is another post that talks about the correct gear ratios for a drivetrain that has powered 250mm wheels + omnis:…th-omni-wheels Once you have this robot built you will again have to trick Modkit by telling it you have all 250mm wheels.