Mecanum Wheels

Hello Vex Forum

What are the disadvantages of mecanum wheels?
What are the advantages of mecanum wheels?

How do you like them?

Please and thanks!

Our team thought about purchasing mecanum wheels over the summer. While they provide a great way to strafe and a relatively compact (compared to an H-drive), the wheels themselves are larger than an omni-wheel. We ended up not purchasing them because we knew we had to keep our chassis small/narrow. If your robot doesn’t have that constraint, and if you are considering them, I would get them. I have talked to teams who have them and say that they love them.

Oh, alright thanks. Do you happen to know if you can strafe if you have the 393’s on High Speed mode?

We’ve tried literally every type of wheel for this game. Omni, Mecanum, 3", 5" and even those silly plastic traction wheels.

Omni>All. Seriously. We loved the maneuverability of Mecanum, we loved strafing, and we loved the look. I even made a custom drive control so that they drove Tank-style for turns with strafing on the shoulder buttons. They were super fun. But they get caught so easily on the Sacks. If you drive over any of them, those little edges just get caught and pulled up into your chasis, stopping you from driving. It was horrible. We have 12 of them just sitting in a box until next year.

Granted, the getting stuck problem is still there with Omni, but it’s much less common. If anyone knows how to prevent that entirely, we would love to hear some ideas. We think we fixed the problem by widening the wheel wells, but haven’t had a chance to drive it.

Of course. It moves at a decent pace, but driving forward always felt faster.

If your robot is not a speed/efficiency bot, low skirting can protect Mecanums from being caught on sacks. We used this successfully early in the season, but then we switched to a different drive because the skirting added weight and made our robot slow.

Teams 1, 1A, 1nd 1B from Michigan used standoffs as a lightweight alternative for skirting, and they also did not have any problems with sacks getting caught.

The problem with these approaches is that your robot can’t drive over sacks; it must push them instead. This can strain your drivetrain a lot, so don’t do it unless it’s absolutely worth it.

Yeah, we’re having trouble getting OVER them, like an ATV does rock formations. When stuff gets pushed out into large piles in front of the trough and they aren’t picked up, it can run into our chassis and get stuck. Pushing sacks around just seems kind of pointless compared to being able to use them as a platform.

Really guys… I get unstuck… all I do is strafe and the sack comes out… but then again I have 8 motor high speed drive…

hello, i have mecanum wheels with 4 x 393s high speed, they work really well, i dont have problems with sacks getting stuck because i boxed around the wheels using c-channel and steel sheet,

they enable great maneuverability, and are brill! … they are expensive, but well worth it, i think there are only 3/4 teams in the uk that use mecanum wheels but they are so worth it … :smiley:

Let me start out with saying that my team started this season out with mecanum wheels. We did later switch to an all omni drive, but this was more due to the fact that we didn’t tend to use the strafing mode much anyways.

Advantages:

  1. Allows strafing while keeping the standard chassis, which depending on how your intake and lift is set up, may be/may not be very important.

Disadvantages:

  1. Much heavier (each mecanum wheel is almost TWICE as heavy as an omni wheel)
  2. Really easy to get stuck on sacks
  3. #2 can be mostly fixed… but that requires adding some sort of skirt, which means even MORE extra weight.
  4. Much wider

So basically mecanum wheels have a much larger footprint compared to omnis, but it really depends on how often you use the strafing in a match.