Re: Round Belting - Solid vs. Hollow, Polycord vs. McMaster
 

How is the polycord with the grip on the balls? Is it similar to surgical tubing?

Re: Round Belting - Solid vs. Hollow, Polycord vs. McMaster
 

Is the grip with the polycord similar to surgical tubing?

Re: Round Belting - Solid vs. Hollow, Polycord vs. McMaster
 

Having handled both lately, the polycord feels a bit grippier. I can't offer you any better insight with regard to hard figures, but there's a difference.

I've had bum experiences with hot plastics in the past, which makes me leery of using any custom heating rigs. That said, I also wouldn't want to use some bum setup with hollow-core belts. Has anyone had bad experiences with them in an FRC setting?

Re: Round Belting - Solid vs. Hollow, Polycord vs. McMaster
 

Falconmaster--
NO, Polycord or the less expensive versions are very different than surgical tubing. Round belt urethane belts are MUCH less elastic than surgucal tubing. The are also, however, less "sticky", but far more than enough to move the 2009 game balls. Surgical tubing stretches too much and is a bit more difficult to attach to itself (Although a volunteer at Hartford Ct regional [can't remeber his name] told me the perfect way. Roll the surgical tubing back on itself and put 1/2 of a one inch section of pneumatic air hose from the KoP up to the edge. Coat the edge of the tube with Crazy Glue then roll the tubing onto the hose. Repeat the process with the other end of the surgical tube and the other half of the hose and you'll have a closed loop which will NEVER break at that point.)
We prototyped the round urethane belt conveyance for this year and it moved it beautifully. The key is deciding if you are going to have one set of belts roll against a stationary wall or have two belts rolling the ball between them. Both worked for us, obviously one is twice as fast as the other.

One mistake many people may have when first trying to adhere two ends together is to heat with a simple flame and hold them together. Using a short (6" or so) length of aluminum angle to maintain allignment, heat to a liquid melt then touch together and pull apart about 1/16 to 1/8" . This is crucial. Failure to do so may give a false sense of adhesion. The separation prevents the hot urethane from being squeezed out by the non-melted belting.

Don't be intimidated by the product. We've used it in '06 and could gather the small balls going 12fps, as fast as we could drive over them.


I hope this helps you. Any questions... message me and I'll help out as best I can.

Re: Round Belting - Solid vs. Hollow, Polycord vs. McMaster
 

Thanks!

Re: Round Belting - Solid vs. Hollow, Polycord vs. McMaster
 

I have to coment on the post by Tom I. He is a friend of mine and he and i have had a change of heart with the bonding of the belting... though i would still not recomend it for a belt it works great bonded to a flat piece of the same material. we used this to make the fingers for our collector this year...

just my two cents...

Re: Round Belting - Solid vs. Hollow, Polycord vs. McMaster
 

some of the cord is reinforced, some is food grade, some is smooth surface, some is rough surface.

the material that is $5.40 / foot is reinforced.

Re: Round Belting - Solid vs. Hollow, Polycord vs. McMaster
 

datasheets are here, food grade and non-food grade

http://www.habasit.com/1976.html

Re: Round Belting - Solid vs. Hollow, Polycord vs. McMaster
 

I have a question about what rollers people are using with the polycord. Specifically for the drive roller and then the idlers. I had thought pvc pipe, but I presume there are other more elegant solutions available. Thanks.

Re: Round Belting - Solid vs. Hollow, Polycord vs. McMaster
 

custom heating rigs like the one you saw me successfully using friday?

if anyone wants to try this with the solid core go ahead and save yourself some money and buy "Weller®/Portasol® Super-pro Self-igniting Butane Soldering Iron Kit"....it has a chiseled tip and work like a dream, plus its like $60 as opposed to $500

Re: Round Belting - Solid vs. Hollow, Polycord vs. McMaster
 

Custom heating rigs like a fresh-cut 2007 kit wheel that burned the heck out of a couple of my fingers. I'm not saying it can't be done--safely, even--but I've just got my biases about the matter. Call me paranoid.

Re: Round Belting - Solid vs. Hollow, Polycord vs. McMaster
 

I believe I have found a vendor that is cheaper than Mcmaster and trust worthy. I'll post after checking thier stocks tommorrow.

Re: Round Belting - Solid vs. Hollow, Polycord vs. McMaster
 

Dcollins
We've milled ours out of delrin rod (lucky enough to have a sponsor who gives us just about all we want). For those less fortunate, you could use schedule 40 plastic pipe with grooves cut, that's a common method. You could also use 1/2" shaft with plywood pulleys. It's simple enough to turn on a lathe or milling machine. There's lots of options.

Re: Round Belting - Solid vs. Hollow, Polycord vs. McMaster
 

No, it needs a larger pulley diameter because it is stiffer. The fact that it is rougher is separate and not really related.

Re: Round Belting - Solid vs. Hollow, Polycord vs. McMaster
 

Back at the Atlanta Championships in 2006 I got a sample of some yellow polycord for a team (sorry I don't remember which team) that is very rough almost like sand paper. It is 1/4" in diameter. I am not seeing something like it at McMaster but it is hard to tell. Does anyone know the exact stuff I am talking about and where to get it? Maybe a part number? McMaster says the metric stuff is "rough" but how rough? It doesn't say about the texture of the inch stuff. What polycord products have teams used successfully in the past? We can't afford to buy a bunch of this stuff to try out so need to limit the selection.