Alternatives to Urethane Flat Belting

Hey all!

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.

5 Likes

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.

2 Likes

As others have mentioned, 3D printing them is a really reliable solution.

Could you explain the problem you are having with keeping them in place? Are your pulleys crowned (convex rather than concave)?

1 Like

+1 one for the timing belts, this year was the easiest transporting system I’ve ever had the pleasure of building.

3 Likes

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.

1 Like

We were rookies last season so we don’t have many timing belts on hand except for the drive-belts. Also, we don’t have pulleys for them either.

Unfortunately, we do not have any access to 3D printers (the school one broke). We need to invest in one eventually.

We are running them directly on the John Deere foam rollers. We are trying out different alternatives to pulleys but all have failed so far.

If only we had extra wheels…and a lathe. Definitely a lot of tools that we need to buy in the future!

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.

We ran them on the rollers for grip. Would the belts be ok being ran directly on a 1/2" hex shaft?

We do not have any access to 3D printing unfortunately.

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.

I have done this many times with great success. Highly recommend as a quick solution.

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.

2 Likes

Probably not. Keep in mind, there is a minimum bend radius for most belts, these included. Also the hex shape isn’t always great.

If you need help with printing or making anything, dm me, we can help (I’m from 2090).

1 Like

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.

Thank you for the idea, we may try this.