Andymark HiGrip Wheels clicking?

Hello!
So 2791 is using the white andymark high strength wheels and we were told by another team that if we start to hear clicking from the drive train, it was a sign that the wheels have a fracture and are at the end of their life. I was wondering if this is still true? And if it is what does it actually sound like? We are currently hearing a click on our practice bot, but we are not sure if it is the click we need to listen for. Any input would be lovely. Thank you!

Is there for any reason locktite that came into contact with the plastic hubs?

https://drive.google.com/file/d/1I2UiiWz5qiXOBZPDUSG9Gx4bMF9PyPGT/view?usp=drivesdk these are tge wheels and I do not believe so

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There’s a possibility that the hub has been over tightened to the wheel.

Its not glass reinforced so the bolts might be stressing the wheel itself.

My steps to kinda correct this is to take the wheel and hub off and just re-bolt on the hub.

However at the same time. Its the practice robot and the wheels are only $6. You probably have a spare one lieing around the shop somewhere if it does end up completely failing.

If the clicking is regular, then it could be a tiny piece of carpet stuck in the pulley. We have had that happen before.

During my 18 months working at AndyMark, I learned a lot of things…but this particular factoid wasn’t one. There are certainly enough other things that could be clicking in a drivetrain.

If the wheels pass a visual inspection (and it looks like there’s easy enough access to do so), I’d also try running the drivetrain on blocks. That should help you isolate the sound to one side of the robot, and probably one end of the drivetrain. That could expose a bearing that’s going bad, or gears that have an issue.

We will definitely check everything, thank you all for the input! I will post an update here when we figure out what it is :slight_smile:

In my experience, those wheel assemblies are extremely easy to overtighten. I would suggest taking each assembly apart and looking for cracks in the wheels and hubs. Our team recently purchased a torque wrench solely for putting these assemblies together.

I’ve never heard of a regular clicking coming from these wheels. They can definitely crack if overtightened, but they only make a cracking sound when you’re cranking in the bolt. If it’s a regular clicking when the drivetrain is running, there are several much more likely issues. Could be a bolt head hitting or a burr in the chain or a cracked bearing or any number of things.

A bearing will create a consistent clicking noise when the bearing balls wear to a point that there is a gap in the ball spacing. The click occurs when the balls “cross the gap” under load. In automobiles this is common in sealed axle bearings that have exceeded their lifespan or sometime after their seals had failed. Typically in excess of 75-100k miles. And more common in older cars than today.

While most sealed bearings used in FRC are extremely similar to sealed automotive axle bearings, just much smaller, I’d have a hard time imagining that a drive train bearing in an FRC robot could ever be put through stresses or heat enough to cause a new bearing to produce that kind of wear. The high rpm of a shooter would be a different story. If it was a really old bearing that had dried out prior to install and has been running dry, its indeed possible the clicking could be a bearing.

A bearing with that kind of wear can still take a significant amount of abuse before imminent failure. The bearings have to wear to the point of seizure or to the point of allowing the races to separate. In an automobile ALWAYS replace immediately because some bearings are used to hold the wheel in place. In an FRC robot, if the wheel is in sealed system where the clicking bearing does not serve the role of holding the wheel on, it can reduce performance or just be a nuisance. I wouldnt think it to be serious danger, but I would replace at earliest convenience since it is likely adding significant drag.

OP’s team has been around for a decade. Mine’s been around 15–someone fished out a random spacer for a sprocket this year that I recognized from the Kit of Parts. In 2006. Depending on a team’s packrat level and how long and hard they run, nothing is impossible. :slight_smile:

Ok. So it is the bearing, but we do not have any spares right now. Is it safe to drive with a clicking bearing?

That will depend.

If it has only just started clicking then that means the bearing balls are now worn under spec. They click because they are still moving so that tells you a bit about the health of the bearing. If it is grinding, crunching, or difficult to turn then a ball has broken and debris is impeding movement. However, the click occurs, usually every so many revolutions because the load forces the inner race to rest into the growing gap as a result of undersized worn bearing balls that jump the gap so to speak. I’ve seen automotive bearings last months in this condition. And ive seen clicking bearings go silent when the load is removed ie car put on jacks. If the click is clean and consistent and occurs at a constant rate relative to speed then I would be less concerned about imminent failure at any second.

However, without knowing the age of the bearing or its lubrication status, any change in noise is an indication of a worsening condition. If you are using the bearing to hold things together, such as a flanged bearing would along the axle vector, this imposes a different set of concerns. Any time you are using the inner race or outer race of the bearing as a means of positioning the bearing to a set location or restricting or mounting items along an axle, that positioning can fail if the two races separate due to bearing failure.

Clicking is usually the first indicator progressive to a grinding or roaring noise as it gets worse. If it is grinding or roaring and the noise suddenly disappears catastrophic failure is imminent within seconds because the balls have seized,. Complete separation of the bearing is generally unavoidable.

While I wouldn’t tear a bot apart in the final matches of a competition due to a clicking bearing I would definitely yank it first chance I got when time permits because the bearing is not going to be able to withstand lateral ramming forces as easily as it could if healthy. Plus, it’ is adding more drag, friction, and resistance to your drive train as it worsens. And it will never improve, but only get worse.