This past year, Andymark introduced a new performance wheel using zip ties to attach the tread which was inspired by 971 IIRC. I’ve heard that 971 has used zip tied tread with much success over the past few seasons. I am wondering what teams who used the new style of Andymark wheels thought after a season of use. Some specific things I am wondering:
What wheel size were you using (4in, 6in, or 8in)?
What was the speed of your robot?
Would you characterize your team’s driving as slower or aggressive (higher speed, quick acceleration, turning at high speeds, intense defense)?
How did the tread hold on to the wheel overtime? Any issues with tread coming loose or shifting?
Did the tread stay securely on the wheel until it needed to be replaced or did it come loose?
If adjusting loose tread was an issue, how often?
Did you noticed performance difference while driving in straight lines, pushing, turning, etc?
Would you use them again or make modifications to them?
Any feedback on your experiences with these wheels is much appreciated!
We had issues with the tread slipping off in our school hallways, and that’s tighter pile carpet than the FRC field. Tried a few different zip ties (high strength, smooth body, etc) without much success. We kept using the zip ties to anchor the ends of the tread, but added 3 pairs of 1/8" rivets 120 deg from each other. No issues after that. It’s a marginally better way to fasten the ends of the tread, but more work intensive to notch the tread to the right length and width.
What wheel size were you using (4in, 6in, or 8in)?
4in
What was the speed of your robot?
Roughly 10 ft/s
Would you characterize your team’s driving as slower or aggressive (higher speed, quick acceleration, turning at high speeds, intense defense)?
quick acceleration, intense defense, lots of use (3 districts/regionals, 1 district championship, 2 off-seasons - roughly 80 matches)
How did the tread hold on to the wheel overtime? Any issues with tread coming loose or shifting?
We also had to rivet our tread on due to treads coming off the rim of the wheel during high speeds and turning. We never had a failure with the zip-tie aspect of the assembly just with the treads sliding off.
Did the tread stay securely on the wheel until it needed to be replaced or did it come loose?
Once riveted it stayed on till tread replacement was necessary
If adjusting loose tread was an issue, how often?
Not an issue once tread was riveted
Did you noticed performance difference while driving in straight lines, pushing, turning, etc?
Nope
Would you use them again or make modifications to them?
Yes i think we will use them again and we will definitely be riveting the tread again.
As Scott said, the fastening of the treads is very neat, however it does not offset the effort of cutting and sanding down tread. We went through many zip-ties and pieces of tread in an attempt to get the tightest possible fit so that we would not have to rivet the tread on. All this work was useless as rivet was the easiest solution to keep the tread on.
Ultimately the wheels are great and I would recommend the hex fit to anyone, just be prepared to rivet the tread onto the wheels.
We used 4" performance wheels, but never used the zip tie mounting method. We put our own hole pattern on the wheels and riveted tread on the entire season.
We used 4" AM performance wheels in a 4WD wide set-up, powered by VexPro single-speed single-reduction 7:1 gearboxes with 3 CIMs per side. Sprocket ratio from the gearbox output to the wheels was 1:1 (34 tooth #25, if I recall correctly.)
We also purchased several rolls of 1" wide brown roughtop from Andymark, and held it on the wheels using wide-head rivets.
While the rivets held nicely, the roughtop tread de-laminated routinely when we were playing defense. 3 CIMs per side is a fun drivetrain; we were speedy, and were able to push many robots, but needed to replace tread after every match when we did so.
I really like the AM performance wheels but we will need a much more durable tread system if we use them again.
We used AndyMark Performance wheels this season. We too drilled out holes to accept rivets into them instead of using the zip-tie method.
Size: 4"
Configuration: 8-Wheel Drive (long)
Speed: ~6 fps low / ~16.5 fps high
Driving Style: Higher Speed, Quick Acceleration, High Turn Speeds
Tread Durability: We used a blue tread from a different provider (don’t remember from where) and had minimum to no maintenance. By IRI, we just switched out center wheels to the outside and put new tread in the middle wheels.
Performance: Worked great, no loss of performance from the wheels all season.
Future Usage: Yes, we like the durability of the wheels themselves, but we would probably continue to rivet out the wheels to accept rivets as well as use the blue tread (because it matches our team colors too ).
Like the others on this thread, we found the regular zip tie mounting method inadequate. We ended up zipting the tread down to the rim of the wheel.
I suspect that if the tread was as wide as the slot and the zip tie didn’t have to do a 90* turn to go into the hole on the wheel, it would have been much easier and stronger to put together. I hope we see a more 971 like design from AM, where the tread is quite wide and the zip tie runs around a central hub without twisting.
3.5 inch diameter with tread 1.25 inch wide. The zip tie went in a groove around the hub so it didn’t slip off. The zip-tie had to be pulled with pliers but we never had a problem with any tread coming off after driving practice, three regionals and champs.
I know 1678 also machined custom wheels based on 971’s zip tie method. From what I saw at champs, they were pretty close to what 971 ran, ~4" diameter and 2" wide. They were very happy with the performance, and made it to Einstein so they saw 2 regionals, divisional and Einstein play.
It seems that the AM wheels had some issue caused by either a tread Width/Diameter ratio, the wheel rim not having a big enough lip and/or the zip-tie attachment method not being as secure as the around-the-hub method 971 uses.
We used the 4in wheels, with blue nitrile tread, on a ~14 fps single speed gearbox from vexpro. And the treads would continually slip off, at the first competition we went to we added one rivet per wheel as well as the zip tie. And by our second competition we had 3 rivets per wheel as well as the zip tie.
Has anyone tried a heat release epoxy? The idea would be to use this instead of rivets, here’s a video that shows how you would get the old tread to come off: heat release. The strength before removal should be more than enough, going from the specifications. I’ll bet there’s an adhesive with properties that would match the requirements for this application very well, without destroying wheels.
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