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Unread 22-02-2015, 19:07
grem110 grem110 is offline
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FRC #4904 (Bot-Provoking)
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Join Date: Apr 2014
Rookie Year: 2014
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Elevator Design Help

Hi,
I'm on a second year team with only freshmen and sophomores (new school) so we're fairly inexperienced. We designed our elevator using wire rope and a worm (20:1, CIM). When we first ran it, we simply couldn't lift our grabber. Slapping a 7:1 planetary gearbox and reducing weight helped, but the worm started to skip and eventually ground down the worm gear into nothingness. We improved the rigidity of the assembly but didn't have time to test with a new worm gear (delays due to East coast storms). Our current plan is to fabricate a gearbox out of 4"x4" aluminum that's perfectly centered on all sides and hope that a new worm gear will do the trick. However, I'm still dubious that it will be capable of lifting our mechanism + 6 totes and we've majorly compromised our speed. I was stupid enough not to check Chief Delphi before designing, but now that I have, I'm trying to figure out where to go forward now that build season has stopped.

Would counterbalancing the elevator be a worthwhile endeavor? If so, do you recommend constant force springs (wouldn't they snap) or surgical tubing?

Would the elevator be effective without an anti-backdrive mechanism? I saw a Ri3D team that just used a 70:1 cim to drive their spool.

Any other thoughts? We're also pretty close to weight limit and are probably going to have to end up cheeseholing at competition regardless...