We are looking at alternatives to the flat belting that everyone normally uses. We have been attempting to use polycord for our ball intake but have run into issues with keeping them in place (and we have no pulleys for them). We want to use flat belting, but are wondering if there are any alternatives for it. Any ideas? Thanks!
More expensive if you don’t have it on hand, but more likely for the average team to have on hand from previous years - timing belts work very well on the balls this year.
Although - does your team have access to a 3D printer, either through the school or through one of your students or mentors? You can simply print polycord pulleys, there’s quite a few effective designs available online if you look for them, and PLA works fine.
We 3D printed ours as well. Works perfectly fine. A lot cheaper and faster if you have a printer in-house.
We played around with the edge heights to keep the belt on.
Our team is also using polytube belting and do not have pulleys. We have found a workaround by using a lathe to make a slot in the purple andymark stealth wheels. It works very well for us.
I think running it on the John Deere rollers may be your problem actually. Do you have access to a 3D printer? You can print some really simple quick hubs for your rollers.
While it’s not ideal at all, if you have a thin enough belt you can sometimes get away with running them on a hex shaft with an electrical tape crown.
Would highly recommend using VersaRollers and taping down some string or O-rings to produce a locating feature. Alternately, the smallest size of Colson Vex sells makes an incredibly solid flat belt pulley for some odd reason.
We found something that works really well for guiding flat belts on tube rollers. There’s a big roll of double stick tape that comes in the KOP. If you wrap a piece of that around a roller, and leave the red backing in place, a flat belt will naturally center itself on the tape. In our intake prototyping video you can see the belts wandering before we used this trick, and what the tape strips look like on the rollers themselves, after we moved to a configuration with no belts. We are, however, using belts positioned this way elsewhere in our ball path.
Like a lot of specs provided by manufacturers, the min bend radius specs have huge safety factors and assume a run time 10-100x as long as an FRC robot. You could be fine.