Grippy material
 

My team is looking for a grippy material we can use to make a roller claw for the offseason, and for other offseason robot uses. Anyone know of a good, cheap grippy material?

Preferred materials must be able to:
-Last a long time (A few weeks at least before changing)
-Be VERY grippy

Thanks for your help!

Re: Grippy material
 

My best advice would be to take a bunch of materials and rub them along the tube. You'll be able to tell which one has the highest coefficient of friction with the tube.

Anyway, I would recommend http://www.brecoflex.com/ . It's not necessarily cheap, but I'm almost positive they'll have exactly what you want.

A lot of teams used polyurethane tubing with success. I can't speak to the friction they provide, but it's probably a pretty good option for flexibility in a roller claw design.

Re: Grippy material
 

http://prolineracing.com/rock-crawling-tires

973 used rock crawler tires. They worked great. Add a touch sensor and a clamping claw and its nearly impossible to remove the tube from its grip.

Re: Grippy material
 

I don't have experience with these, but i know that colson wheels are very sticky/grippy, and teams have used them in the past for drivetrains and whatnot.

Re: Grippy material
 

We used 3/16 polyurethane belting which was threaded in a double helix around and through holes in 1/16 polycarbonate tubing.

It was the grippiest (most grippy?) out of all of the materials we tested and we never replaced it the entire season.

We get our stock belting from mcmaster. It comes in a variety of sizes and has about a thousand uses. We actually also used it to power our collector this year. It can be cut to any length and once it is heat welded, the weld is as strong as the rest of the belt. The best way to weld it is to buy the actual welder however a lighter would also work in a pinch. Another cool benifit is that it acts as a built in clutch. (Such as our ball manipulator in 2010) I highly suggest you pick some up.

It can be found http://www.mcmaster.com/#about-belts/=e0psnh

Re: Grippy material
 

The thicker sections of that polyurethane belt (e.g. 0.375 in V-belt) can be welded effectively by simply using an electric hot plate (or a stove), and heating up a piece of metal (or a pan), melting the ends of the belt on it, then quickly placing the belt in a jig to cool.

Re: Grippy material
 

Our team used urethane tubing, Mcmaster #6567K57. Here's a video of the finished claw: http://www.youtube.com/watch?v=bRBImoFlNs0

Michael

Re: Grippy material
 

Are you looking for just a material for existing rollers or do you want good rollers?

I would recommend the highly affordable and and hexed green banebots wheels. You can make a great roller claw with those.

http://banebots.com/c/WHB-WM-HS4

Re: Grippy material
 

For the rollers on the end of our grabber, we used...dog toys. The kind that were rubber balls with the small nubs on them. They worked absolutely amazing, had a better grip on the tubes than any other material we could find, even better than plaction tread. The belts were polycord though, and they worked well too.

Re: Grippy material
 

We used good old-fashioned plaction tread from AM. Works great. It's conveyor belt material, so it is very durable. We never changed the roller material in testing or two regional events and two eliminations and some post-season stuff.

Re: Grippy material
 

Just within the FIRST manufacturer/reseller community, we have 2 fantastic grip options in terms of roller claws, both of which have been mentioned here. I have used the BaneBots wheels on DIY home-built robots before, and I cannot help but attest their capability. They have a decent coefficient of friction, and are sold in ideal sizes for small robot applications, or, in this case, the proven roller claw.
Additionally, never set aside the ubiquitous AM Plaction/Traction treads when looking for tread options. It suffices to say that nearly every FIRST team has at very least played around with the stuff, while most have left over stock in their storage rooms. It works. That's why AM chose it, among many alternatives, to sell to the FIRST community.
I think that in terms of a roller claw, both options are more than sufficient. If you are looking for the better CoF, definitely go with the AM Plaction treads. If you prefer simplified mounting and a very reliable functionality, then the BaneBots wheels might be a better choice.
Cost wise, you must keep in mind that to use the AM treads, you must also purchase wheels. It is also necessary to have riveting capabilities. If you were to choose the BB wheels, which may prove to be cheaper, you will probably need a lathe to turn the ends of the hex shaft, such that they can fit in what would probably be 3/8" bearings.
Either way, good luck on your bot renovation!

Re: Grippy material
 

Thanks for all of your input! Our lead mentor likes the idea of polyurythane (may have spelled it wrong) belts. Keep the ideas rolling! We may use some for a tshirt launcher....

Thanks!

Re: Grippy material
 

BaneBots green wheels worked superbly on this year's tubes.

Re: Grippy material
 

We had a miracle grip material for our clamping claw last year; egrips can be bought in tape-like rolls and easily has a COF>1 on just about all materials. By far the grippiest stuff I've ever played with. A little pricey, but I have no doubt we'll use it again in the future. (short demo showing its original intention here)

Re: Grippy material
 

So this is that "cell phone grippy case stuff" you guys found. :)

We settled for roughtop tread and later surgical tubing to make our pinch claw grippy. Didn't work as well as we hoped.