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Unread 02-04-2009, 01:21
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Re: polyurethane tubing

Quote:
Originally Posted by Aren_Hill View Post
see also the god of polycord:
http://www.chiefdelphi.com/media/photos/33403
all welded i believe, i'll let Adam chime in on that

yeah...lol its good stuff
I just changed my usertitle thanks to your inspiriration Aren.


Well, pretty much; I don't see any reason not to do solid core. We bought our 1/4" for $0.60 a foot, just try to beat that with prewelded or the barbed kind.

In terms of welding, we just use a soldering gun with a flat tip, and initially used a jig that was thick aluminum plate with a 1/4" groove. We would've done all that way but found just the jig from the welding kit on ebay for $50. The jig made it easier to keep the waste material consistent, and made the process faster. With 74 belts per robot, and changing center to centers along with stretch several times, it added up.

Our process has always been this. Cut to the length we desire (we made an excel where we put in waste material, desired stretch, and pulley Center to center... it spits out what length to cut to) melt the ends nicely, squeeze together (same process for both plate and jig). We end up with a good deal of excess material around the weld, we initially trimmed it with dykes, but in a moment of laziness I found a belt sander with fine grit works GREAT.

I've strength tested every belt welded myself, the kids think it's because I'm fearless, I think it's because I'm stupid. So far, only ones with obviously poor welding have broken, and only 2-3 at that. As shown by Billfred, I tested HARD; usually by stepping on one end and pulling up with both arms.



Sooooo. In other words, we'd do the same thing in the future.