Swerve Wheels

So I originally planned on using Colson wheels for the swerve drive im designing, but these wheels only come in 1.625" and 2.5" diameter size, and are rather wide. I am considering switching to the 2" banebots wheels because they are a nice medium size and are considerably thinner. However, I am not sure these wheels have the robustness to last any considerable length on a frc drivetrain. Just looking for peoples experiences with banebots wheels. Thanks in advance.

Colson wheels are available from 1.625" to 4".

2 Likes

Why are you trying to use such a small wheel diameter?

If you are interested in colsons, in addition to the 1.625" and 2.5" sizes you mentioned, VEX also sells 3", 3.5", and 4" diameter wheels that are also thinner that might package better.

I’d recommend using mecanum instead of colson wheels for the optimal drive train.

6 Likes

If you can’t find the perfect wheel width for your swerve, colsons lathe down pretty easily with sharp tooling. There’s a bit of a learning curve, but it works.

I recommend 4” diameter for swerve. My team (3082) has 4” traction wheels on our swerve this season, and they have been working wonderfully. I would be cautious of anything much smaller. There’s a reason you don’t typically see hefty FRC robots driving around with 2” wheels…

1 Like

I would personally only run 4 inch wheels. Small wheels are meh

4 Likes

If I recall correctly, Colson wheels slide one way more due to the grain of the carpet. Which means you might have some not-so-happy programmers…

Source

1 Like

This is really only an issue when you’re doing complex auto routines. For regular teleop driving this effect is basically negligible. I might be wrong but I believe I remember that 254 was seeing an error of less than 10% when they were tuning their multi-cube scale autos last year. If anyone has some more specific info on that I’d love to be corrected.

1 Like

4" seems right. If you’re really concerned about making your modules shorter then maybe 3"-3.25" would be okay too. I’d be extremely hesitant to go any smaller than that only because I doubt we’ll ever see a truly flat field again. Based on the trend of more complex fields I think there’s always going to be some cable carrier or something in the middle of the field that you’ll have to cross. The anemic ground clearance you’ll have with a 2" wheel will significantly limit your ability to traverse those.

Also regarding banebots wheels, I don’t think I’ve ever seen those on an FRC drivetrain. Only FTC drivetrains or FRC intakes.

1 Like

If I remember correctly, 2767 used 2.5" Colsons in 2017 and 2018. Does anyone know if they are doing the same this year? Their choice does seem to be an anomaly among top level swerves I’ve seen.

What exactly is the reason why large wheels are better than small wheels?

1 Like

I’m not 100% sure but I would assume ground clearance. If you have a bevel gear on there and use it for a reduction that would probably give you very little ground clearance.

Speaking generally, bigger means more material, which means more durability.

2017 was a purely flat field so smaller wheels allowed them to have lower ground clearance which is important for CG concerns. larger wheels tend to fare better with obstacles / uneven surfaces.

We ran 3" colsons in 2018 and was happy with them overall. We saw a decent amount of radius wear on the edges of the wheel, but we contribute this mostly to non-refined steering control resulting in “digging” into corners when changing direction.

On 3419 typically use 4" versa wheels from Vex ( https://www.vexrobotics.com/vexpro/motion/wheels-and-hubs/versawheels.html ). This year we switched to 3.25" versa wheels for the lower weight and size, and the performance has been good. They do wear noticeably faster, though, so you need to keep an eye on it and replace them as necessary.

They are currently creating their own wheels. They had issues along with 254 with inconsistencies using Colsons. They are using their MarkForged to 3D print the hubs and then I believe vacuum forming tread onto (atleast they were messing around with that at one point). The wheels do look smaller than 4" this year, but I couldn’t remember a size.

Everything Type said. 3" customs. If we hadn’t gone down the custom path, we would have run the 3" colsons this year.

1 Like

To answer your original question - definitely don’t use the Banebots wheels in a drivetrain. They will only last a couple of minutes, if that, at the hardest durometer they offer. They are GREAT for intakes and mechanisms, but terrible for drivetrains.

The reasons people are wary of wheels smaller than 4 inches is that, among other things, smaller wheels wear much more quickly. You can roll on a set of 4" Colsons for about an entire season without changing them, but much smaller than that and you’ll want to change them about once per event. If you don’t change the small Colsons out, you will actually notice a diameter change great enough to affect your autonomous mode (and it’s not a niche edge case thing like the carpet grain direction stuff talked about above).

Now that I’m not tired, if this is your first time designing a swerve, I would stick to using 4 inch wheels. Get the experience by designing something bigger, then use that knowledge to make it smaller.