AndyMark Compliant Wheels Warning

For anyone who is using the new green 2" compliant wheels from AndyMark, I would warn against it. After using the red wheels last year I decided to try the newer green compliant wheels. We have been using them on intakes for about a week and the shaft has created a bigger hole so the wheels won’t spin if anything touches them. We never ran them above the max RPM listed on the website so I would argue this is not my fault. Unless I’m doing something horribly wrong with them, I think this is a huge flaw for a $6 wheel that was included in the kickoff kit. If you look at this picture of a new green wheel, a 1 week used green wheel, and a HEAVILY used red wheel, the difference is clear.

It also looks like they switched the red wheels to a different material that they injection mold rather than cutting them on a waterjet, this makes me worried that any new 2" red wheels would have this same issue, even if it takes a little longer to wear down. The red wheels we used last year were extremely durable, loosing almost no material, so I’m a little upset that, what seems like a far lower quality product, is being sold at the same price. If anyone has had a similar experience, please feel free to share.

Usually it would be appropriate to contact the vendor and see what they have to say. What has Andy Mark said on the issue? Has more than one wheel failed for you yet? We were just talking about these wheels for our intake.

1 Like

Consider the load on the wheels to include the compression. Even if you don’t exceed the rpm, if there is too much of a force applied then it will cause the wheels to spin slowly over time and stretch the hole.

I would check your compression and try again or use a different wheel. The 4” has a plastic hub that works quite nicely in our testing.

I second the idea of reaching out to the support team for more information. Andy’s team does a great job with customer service.

From the looks of that, it appears that you have more traction between the wheel and cube than you do between the wheel and shaft. In addition it looks like the motor/gearbox you chose is powerful enough to overcome the traction between the shaft and wheel.

My suggestion is to either choose a weaker motor (one that can withstand stalling, or put a limit switch where the cube comes in to stop the wheels from turning once you ‘own’ the cube.

We did an off-season gear grabber this summer and reached out to the 2" red wheels based on their strong in-season performance for teams like 254. We ended up with the newer molded version, and were disappointed with their performance and durability. We had them delaminate across some molding knit lines and also saw early hex failure on them. We had to abandon them at the prototyping phase. I agree that the waterjet wheels were of higher quality than the new molded wheels.

I agree with the above statement. The water-jet ones were 10x better.

They sell wheels with a 1/2in plastic hex bore. Those are the ones we’re using.

Probably about 10x more expensive to make too.

Those are 4in wheels, they’re hardly a drop-in replacement for a 2in wheel.

Yeah, I know. Just saying.

Full Disclosure - I haven’t used any of the new molded 2" wheels

The red wheels are a different durometer than the green wheels. I would not expect the green wheels to have the same lifespan of the red wheels.

I suspect the maximum RPM has to do with structural integrity of the wheel, not it’s ability to not slip under load.

I got one of the sample 4" green compliant wheels at world’s last year, and I did see delamination on those just with playing around with it by hand, but I chalked that up to being a prototype of the low durometer material. We did test/use the black and blue 4" compliant wheels on last year’s robot and didn’t have any issues with mold quality.

Cannot comment on the difference between the injection molded and the waterjetted ones, but if the issue is between a green wheel and a red (technically maroon) wheel having different material, lifespan, and durability, that wasn’t a mistake. They are different materials, intentionally. Green Compliant wheels are 35A, whereas the Maroon wheels are 45A. (Blues are 50A, if you were curious.) From what I’ve heard from my friends testing a variety of intakes, the extra 10 shore makes a world of difference in lifespan.

While I appreciate the warning, you know back in the day we used to solve these sorts of problems without vendors like AndyMark even existing. Heck, we didn’t even have hex shafts back then.

+1 to this. We really like the original red wheels.

OP, I think you need to evaluate your use-case for the green wheels and adjust your design accordingly. We have a ton of the new green wheels and actually quite like them, though we understand that we cannot drive them as hard as some other wheels, such as the old reds.


Not sure what shaft size you are running these on (the hex hole is 3/8"), but we have had moderate to great success stretching these wheels over a 1/2" shaft. They tend to slip significantly less and seem no worse for the wear.

That’s exactly how they’re intended to run:

Doh! Reading the product page would have definitely helped!

Now I am sitting here wondering how many other products from various vendors I could learn something from by reading the product pages…

[offtopic] Insert complaint wheels pun here [/offtopic]

Carry on.

For what it’s worth, 5499 managed to tear through a few of the red wheels over the course of the season. We actually had a couple tear at one of the hex bore vertices. I’m not surprised that the softer green wheels wear even faster.

If it’s primarily a problem of the hex spinning inside the hole, it seems like that’s solvable in software. There has to be a minimum torque required for that, so use Talons and set a current limit. Or what about 3 zip ties through the web holes compressing the hub even more to the shaft? That’d take up a little extra space above and below the wheel, but might get you more reliability.

I stopped counting how many times I told students to read the manual/datasheet/product page years and years ago…

How about drilling a hole through the center and shaft and inserting a roll pin through both shaft and wheel center material to keep the wheel from spinning on the shaft. Simple fix.