Attaching treads to wheels

For attaching treads to wheels, it seems like there are 3 common methods here:

zip tie method:
https://www.andymark.com/products/4-in-performance-wheel-with-nub-bore?via=Z2lkOi8vYW5keW1hcmsvV29ya2FyZWE6OkNhdGFsb2c6OkNhdGVnb3J5LzVhZjhlMjViYmM2ZjZkNWUzNmYyMzk0NA

alligator clip:

rivet or screws:

For those who use or have used treads, what have you found to be the best method and why? what are the pros and cons to each?

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Note: This wheel is designed to utilize rivets to attach the tread to the wheel. AndyMark recommends steel 1/8" diameter rivets with a 0.251" - 0.312" grip range. The wheel has been manufactured with no holes on the rim, as it is intended to be a blank canvas for teams to install rivets freely.

We riveted them on, when we used wheels that required adding tread. The Performance wheels used to come with holes in them, it was fun setting up a jig to drill matching holes in the tread.

Could you explain what your jig is? Looking for some good options for this.

We used a piece of the old kit chassis, which is a channel with a 1" wide inside dimension, and drilled holes in it where we needed to drill the tread. Lay the tread in the jig, drill away. At least that’s what I remember…it was 8(?) years ago.

yeah, it was laying in my scrap pile. Have fun! (something had to fit inside to support the tread, my guess is a piece of 3/4" plywood clamped in a vise would do it)

This is a subject I would like to learn about as well, having personally not used treaded wheels since about 2007 or so.

As our team’s first foray into this subject in the modern era of FRC, in May we purchased some WCP-0075 aluminum wheels, McMaster 5994K9 nitrile belting, and the Armabot tread prep fixture.

We were very surprised to find that:

  1. The WCP wheel is tapped for 10-32 fasteners for tread retention, not drilled for the 1/8 rivets we planned to use. Aiding in this confusion was the fact that WCP resells VexPro’s Tread Attachment Rivet kit 217-0396.

As our team couldn’t stomach the idea of putting 10-32 BHCS into these holes, we decided that we’d drill them out to fit 5/32 or 3/16 rivets instead.

Unfortunately, drilling out the holes takes the wheel out of its COTS state. We’re a team that follows the strictest possible interpretation of the build season schedule rules, so (under current rules) drilling the wheel will make it legal for us in only 2 seasons:
Season 1: 5/32 rivets
Season 2: 3/16 rivets

In season 3, perhaps we’ll drill a new pattern of attachment holes in the wheel rim.

  1. The tread attachment hole pattern is asymmetric; after preparing the tread, it’s possible to accidentally start assembling the tread onto the wheel backwards. This is an inexcusable error from a design perspective and a major pain in the butt. Designer, please identify and explain yourself.

While I agree this is confusing, since there is no clear indication that it is tapped for 10-32, keep in mind WCP also sells Vexpro Traction wheels, which do use the rivets.

from what I can see, the hole pattern seems pretty logical, I don’t quite understand your problem here. my understanding is that treads need to be attached not just at each end, but also at other places around the wheel to ensure the tread stays on, so each hole set looks to be about 120 degrees apart. the set of holes that are close together are where the ends go, so that the ends of each tread are fastened down as much as possible.

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Right, that’s what we expected also, but it is not the case.

So like Nate said, if you start putting the tread on backwards your holes won’t line up.

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ok, so I just looked at the cad. three of the holes are 120 degrees off, while the 4th one is 20 degrees off of one of the other sets. I see the issue now. I’m not sure exactly why it was designed this way, however this might somehow relate to why they chose to tap it with 10-32. that way rather than having to drill out the rivets, you can just unscrew the tread. tread wear might have been be seen as an issue, so using 10-32 screws might be better not only for installation but also for maintenance reasons.

Nate,

We added tapped holes because the bolts don’t shroom out like rivets over time and its easier to replace tread. We’ve been using about the same design since 2011. The tapped holes are much more expensive to add and imho miles better. I don’t see the value in rivets here, but teams are welcome to drill their own hole patterns or drill them out. I don’t know if the other wheels on the market even have holes.

The rivets are for the vexpro traction wheels.

The designer would be me here, similar thought process we’ve “always” done it this way. Space 120 and then add another hole to finish tying the end of the tread together. I’ve never heard of my kids complain about the holes not lining up or putting it on backwards. It probably helps that the kids don’t rivet the tread on and just use bolts.

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Just curious, have you considered designing the holes so that the tread is symmetrical? while it may not be a big issue, it might be nice as far as quality of life goes.
49%20PM

Can you recommend a bolt options for use? We’ve been looking at 91802A001.

I absolutely believe this. I wish you’d take credit for your hard work by mentioning it on the product page!

Cole,

I will be honest, looking back it we should’ve done that. Its one of those we’ve done it for so long/no issue kind of thing so we never made a change to it. I’ll look to make a change, my worry is teams/armabot have already made a jig for this wheel. Would hate to redo/scrap that. But I will agree with Nate that symmetrical would’ve been smarter. It just wasn’t an issue that we thought to fix. Most of the time we product test on the team and we figure if its good enough for us most of our customers will be happy. Sometimes we are wrong.

Nate,

Fair point, will do. We’ll be doing a lot more product detail/information stuff after we finish R&D/stocking later this month. I appreciate the feedback to make stuff better.

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Preston,

Pretty much any button head bolt would work. We use: 91255A265 because we just stock it on the team. Basically you want a bolt with a large head that has a flat surface so the tread doesn’t pull through. I think we tried FHCS but the tread would pull through.

The main reason we hate the rivet is that it wears over time and the students will incorrectly drill out the rivet. With the bolt its unscrew, replace if needed.

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RC, do you guys loctite the screws in when mounting the tread to the wheel or anything? I’ve always had concerns that screws would back out but clearly if you guys have done it this way for this this must be foolish of me.

Have you considered selling a 3" wheel? I would be very interested. Especially if it had a bolt pattern, preferably one that could mount a bevel gear that fits on a 3" wheel…

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^^^^^^^, I’ve been working on a swerve, and I wanted to use a 3” wheel that has a pattern mount and is dead axle, but couldn’t find one. I would definitely be interested as well

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Bolt heads that mark carpet will invite scrutiny, from referees and inspectors.

Audible gasp

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