Our top roller on the snail bot has one rubber band breaking each test cycle. No other rollers have this problem. The rubber bands are not contacting anything except the ball and are attached the same way the bands on the other rollers attach.
Does anyone have an idea of why this is happening or if it has happened to you?
It may be the rollers are rubbing on the spacers that are on the axle. That is what happened to my team for a while. Make sure to actually rubber band then well and out of the way of where spacers may be contacting the sprockets. It sounds dumb but that’s what was happening to us
If your top roller is really close to the goal, it could be because the rubber bands spread outward when the roller is spinning fast which would cause them to scrape against the goal rim, the underside of which is really sharp for no reason
But but, a more recent Q&A entry, this one from Turning Point, suggests that rubber bands do need to be made from the same material.
(Note that previous season’s Q&A rulings do not automatically carry over.)
But the real point here is that last sentence in <R6d>:
It is up to inspectors to determine whether a component is “identical” to an official VEX component.
If an inspector really wanted to, they could perform some sort of “elasticity testing” on your rubber bands, and if they determine that their elasticity is substantially different from the VEX bands, they could potentially fail your robot for that reason. But I’ve never heard of anyone doing anything like that, and think it’s pretty unlikely that anyone ever would. In pretty much all cases, the inspectors’ procedure for determining whether your rubber bands are “identical to legal VEX parts” (if they perform such a check at all) will consist only of checking their size.
So, two takeaways:
Practically speaking, can you use rubber bands made from different materials than the VEX bands? Yes, teams do it all the time.
If you’re at all worried about the material your rubber bands are made from, save yourself the trouble and buy a 1lb box of Alliance Non-Latex #64 rubber bands (less than $5 on Amazon for multiple seasons’ worth).
I’d only add that I assume the (albeit remote) possibility of being called out on rubber band material type as an issue likely increases with the size / status of the event. Probably little (to no) concern at regular local events, only a bit more at Regionals / States events, and the most at Signature Events / Worlds.
My recommended “test” - if a random-material rubber band is genuinely giving you enough benefit over a non-latex one that you feel it would be a huge detriment to the robot if you had to suddenly change to all Vex ones… then you should probably start considering that those replacement bands may not, in fact, be functionally identical and SHOULD fail inspection (whether they do or not).
1lb for multiple seasons worth?! WHAT?!! I’m going to have to go have a talk with those kids… [stomps off to ask team where all of the rubber bands have gone]