Best type of "pulley" material
 

My team has decided to use some sort of pulley/tread system to get the balls off the ground and into the hopper.

However, for the distance that we are going for there just are not any standard lengths. We have done some research into the endless belts, but have not found any easy way that we can make them ourselves and have them be strong.

What kind of rubber tube, flat belt, etc. would be easiest to make a custom length and where could this be purchased?

Re: Best type of "pulley" material
 

Re: Best type of "pulley" material
 

My team ran into the same problem. We discovered that the green padding that goes under hard-wood floors had the properties we were looking for. It has a little stretch which will allow it to go around our rollers and has enough friction to lift a ball quickly into a hopper. The only problem is that it is similar to duct tape; if it gets a tear along on a particular side it pulls that strip off. My teammates and I are taking measures to prevent this.
We are attaching the material be using thick thread and some kind of fabric glue ( I'm not exactly sure on the glue). We tested this method and it failed after four members of the team pulled as hard as they could. The test convinced us of the designs integrity.
The material can be obtained from any flooring/tile store.

Re: Best type of "pulley" material
 

We just got some hollow core round belt from McMaster that has little barbed connectors (sold separately). I was skeptical at first, but it turns out those little guys hold a lot better than they look. It takes some pretty violent tugging to get them back apart again. Also, the plastic and aluminum connectors seem to behave about the same.

Re: Best type of "pulley" material
 

Have you found a source for 3/8-inch shaft pulleys for that 1/4-inch round belting?

Why? Oh ... no particular reason...

Re: Best type of "pulley" material
 

If you want wide flat belting, then consider the stuff that is sold as both non-slip carpet under-padding and as non-slip shelf lining. It is a nylon fiber mesh (kinda like loose window screen) with a coating of rubbery foam-like material along the strands. (Kinda hard to describe, sorry). It's sold in rolls 12" and 24" wide for shelf liner (I got some at "the container store"; I'm sure it's available elsewhere), and rolls and sheets (like, 9' x 12') for under carpets.

The 'belt' is cut to length and the ends are sewn together (yes, needle and thread - choose thread wisely, and space out the stitches from the ends for strength) to make a loop.

The stuff is amazingly strong, and quite grippy, with hardly any stretch.

Good luck, see you in Trenton.

Don

Re: Best type of "pulley" material
 

I hate to give away all our secrets ... but yes. We went with black acetal idler pulleys from SDP/SI (A 6M 9-03110). All we had to do was drill the centers out to 0.375 and put keyways in the ones we want driven (provided the torque isn't too high). Combine with keyed shaft or steel tube and you are set!