Mecanum Wheels for FRC

My team used some 8" Andymark Mecanum wheels that we had left over from several years ago, however we are around 4 pounds heavy and would like to explore possibly changing to some lighter 6" wheels to help with our weight problem. I see a set of 6" on Andymark for around $400 but that would take pretty much all of the budget we have left for spare parts. I found this option from Nexus Robot that is significantly cheaper and would save us the weight:

Does anyone have experience with these wheels or similar Nexus Robot wheels for FRC drive trains? The load capacity is listed as 15kg which puts them right on the edge of being acceptable for a frc bot at the weight limit. I would love to know if these wheels will hold up and if they are grippy enough if anyone has any info. Other suggestions are also welcome if you know of better options. I know vex also makes 6" mecanums but they don’t bolt right up to the andymark hubs and pulleys so would be a more difficult swap.


Team 3319

That almost seems like a cheap knockoff of the AM 6" wheel, down to the 1.875" bolt circle and R8 bore center. Not sure about what the rollers are made of though or if they even have bushings. I wouldn’t push the load rating on those, though.

That said there’s no reason the Vex mecanum wheels wouldn’t work for you. It wouldn’t take a lot of work to make the AM products compatible with them, or Vex sells affordable products.

I think you are incorrect about the bolt pattern; AndyMark hubs and Vex hubs are the same pattern and are interchangeable these days. Anyway, if you want some 6" mecanums, my team has some that we could pass on to you at a discount, so you would’t blow your budget, win/win. PM me and let me know if you’re interested. We have both the old AndyMark models and the Vex models from 2015. You’d probably need to replace a couple rollers on the Vex ones, but we have spares we could give you too.

I would look into the VEX mecanum a little more. We have used the AndyMark hubs with them in the past. The only problem is the hub won’t be flush against the wheel and will instead stick out a little due to the bumps for the locking of VersaHub.

I would also highly recommend sticking to the same diameter wheel. Going smaller will result in your robot travelling faster. You’ll save 2.5 pounds per wheel just switching to VEX mecanum wheels.

I would be really worried about the load ratings. 15kg per wheel is 33 lbs, for a total across 4 wheels (assuming you are evenly loaded, as you really should be with mecanum) of 132 lbs. Consider that your battery is going to be about 12.5 lbs and your bumpers will be at least 5lbs (and could be as much as 20 lbs). A max weight robot is going to exceed those load specs. Even one that is below max weight may exceed than as weight shifts while playing - moving an arm, adding the weight of a cube, acceleration or defense…

I would much sooner go with the Vex Mecanum wheels, and make whatever changes are needed to get them to mount with your setup.

All else being equal, smaller wheel diameter means lower top speed.

VEX does make 8" mecanums which weight ~ 0.6 lbs less per wheel than the standard 8" AM and ~ 1.6 lbs less per wheel than the 8" HD AM. Changing your wheel size will affect your gearing as well ground clearance, robot/manipulator height, and bumper height (assuming you already have them mounted to the bot in the bumper zone).

Oops, my mistake, my point of changing top speed still stands just wrong direction.