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Unread 20-09-2015, 13:50
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MechE
AKA: Craig Rochester
FTC #8470 (Team Technado)
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Join Date: Jan 2012
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Location: Boston
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Re: [FTC]: Drive Platform- Design Exercise

Drive Platform Design Strategy

My son and I have been thinking about this season's game vs. drive platform design. The "Mountain" element provides new and difficult challenges that are very different from previous years. Here are some of the issues we've been thinking about:
  1. Scoring- The scoring capability related to drive design is challenging related to climbing the mountain. We estimate that purely driving/climbing ability can score 80 points by driving up to the "Mountain High Zone" (40 autonomous & 40 tele-op). And... if the robot can climb to the High Zone, we'll be able "hang" using fairly simple mechanisms (80 points hang & 20 points "All Clear Signal"). So... climbing could affect a total of 180 points for the team.



  2. Drive vs. Climbing- To climb into the High Zone, the robot has to climb the 30 deg angle ramp and drive over the "churros" (rungs), and then climb the rungs at 50 deg. We're thinking of the High Zone as a ladder leaned at a 50 deg angle with rungs spaced at 5.33" intervals. Possible drive types:
    • Standard 4" wheels- will fall through the rungs
    • Big wheels- approximately 8", wheel base is only about 8" and center of gravity (COG) must be low or robot will flip. Wheels could "trip over" debris; hindering autonomous navigation.
    • Tank treads- much more complex system to design than wheels.



  3. Physics- Any wheel or tank tread design will not have enough friction to climb at 50 deg with smooth contact with the rungs (assume < 1 coeff friction) . The treads or wheels must be able to "grab" the charro or the charro's ribs. The power required to climb 50 deg is much higher than previous years’ 15 deg incline. It’s complicated, but we’ve done a rough estimate for a 30 lb robot with wheels, and got about 500 in-lb torque at each axle.


Last edited by DavisDad : 20-09-2015 at 13:57.
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