This season our teams have (for the first time) experienced many issues with Omni Wheels breaking. I have added a few photos to show what’s happening with them. I have spoken with VEX and they have always been willing to send us replacements (these were all purchased this past summer). What surprised me was that according to VEX we are the only school experiencing issues like this. They suggested I see if other teams have had issues and had just not been reported.
I’ve personally never had that issue. It may be too much force on the inserts so mabye the drive is bring cantilevered? Other than that, you may just have bad luck and all of the replacements are “lemons”.
Teams at EC3 have had that issue. I’m not certain of how many teams it has affected, but at least two, and I think it’s more than that. Some have broken more than one set of wheels. Initially it was thought to be because maybe a robot was dropped on a hard surface, but by now that seems unlikely. Could be from crossing the starting bar (that’s another theory that was discussed) but it happens on wheels opposite the mobile goal lift with equal frequency. So that’s unlikely.
I have seen it as well, I think it might be caused by changing the inserts, but I don’t have any real proof.
Thanks for posting. I shared this with the engineering team, and they noticed the bubbling in the plastic in the first image. Would you happen to be using any kind of Loctite on the shafts driving these wheels?
We have broken 5 of those this year between two separate teams. All were the older ones without the replaceable inserts.
One of my HS teams used loctite early in the season on two wheels. Since then we have not used any loctite or other material in the wheels and still have them frequently breaking.
Fairly certain this isn’t a legal use of loctite
Loctite has been known to dissolve / weaken ABS plastic parts (the Omni-Wheel hubs), and can cause them to break under load. This could be a contributing factor for some of your issues.
This is the first time that we’ve heard of this issue, so hopefully this is just an isolated incident.
Good thing we only used it on those two wheels at the beginning of the season.
More than two broke, so i’m not sure what caused it on the other ones.
Ours are stripping out really bad.
I’ve had this issue before, when only one insert was fully into the wheel. If you weren’t already doing this, you might want to tighten up spacing on either side of the wheels.
The advice will be useful to others reading this thread.
However, @Powerbelly has been at this a while, and his teams build good, sturdy, reliable robots. (There is ample empirical evidence available for that claim, and note it’s not him making it.) For his case of breaking the four inch omni wheels (and for ours) loose spacing on the axles is unlikely to be a contributing factor.