Quote:
Originally Posted by Chris is me
Those chains and sprockets look much more able to withstand the forces of a drivetrain than the Vex kit, which screwed me over during my hasty rebuild in 2008
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You are right, #25 steel chain is going to be stronger than a little plastic chain. It's also going to be greasier, heavier, more expense, take up more room, and be harder to install and size. The right part for the right job. I suspect the decision to use standard #25 chain (if that is what it is) has a lot more to do with finding an off-the-shelf part that doesn't require engineering, test and manufacturing than it does with providing the perfect technical solution for our robots. The advantage is lower cost than if they had custom-made a metal chain.
VRC 418 had the little VEX chains in its drivetrain and went through two tournaments and the World Championships without a single failure. They were finalists in the Technology Division.
VRC 417 had the little VEX chains in its drivetrain and went through two tournaments and the World Championships without a single failure.
VRC 575 had the little VEX chains in its drivetrain and went through three tournaments and the World Championships without a single failure. They won the Think Award, came in second place in the World Championships Programming Skills Challenge, and had the highest recorded competition score of the year in PSC. You can see a pretty good picture of the drivetrain here:
http://www.vexforum.com/gallery/show...rchid= 347651.
Given the yards of #35 chain I've seen on the floor of FRC fields over the years, I'd conclude that it is entirely unsuited to drivetrains, too.
It's not the chains, it's how they are used. They are poorly suited for a heavy-lift application, but we've had terrific luck with them in drivetrains, and for "medium lift." In 2007 we used them to drive the lifting mechanism for the softballs, and they never failed (frankly, I was surprised).
As you mentioned in your post -- testing is good.