[archiver]

Posted by Dodd Stacy at 1/23/2001 9:18 PM EST


Engineer on team #95, Lebanon Robotics Team, from Lebanon High School and CRREL/CREARE.


In Reply to: 3 Choices - Hurt Carpet, Motors or Wheels
Posted by Raul on 1/23/2001 6:59 PM EST:




: However, be aware that if you do use sharp edges as a way to get great traction , FIRST will likely ask you to do the carpet test. I believe that means running your robot against a wall. So in that case you have to make sure that you have so much traction that it will just stall your motors. I think TKO had this configuration with their tank treads in 99.

: Raul

FWIW. In 98's Ladder Logic, we anticipated just this scenario. We machined little pyramid spikes, about 1/16" square at the base, on aluminum wheels and geared just tall enough to stall the motors up against the wall. The tech inspector took one look at our wheels and put us to the carpet test.

However - surprise - when he saw that we stalled, he lifted our wheels off the ground, let them spin up to free speed then lowered just enough weight back down on the carpet to load the wheels heavily (at full stick) but not quite stall the motors. Needless to say, you can burn the carpet with rubber Skyway tread with this test.

Fair? Legitimate? We didn't think so at the time, and I still think it was arbitrary and discriminatory. But I'm not posting to rant. I'm posting to warn inexperienced teams that this is a gray area, and the FIRST folks have a playing field to maintain. They are not obliged to take risks with us tearing it up, and they make the rules. Be prepared with conservative options if you want to push the traction envelope, or be prepared to trailer your bot without competing.

Dodd

PS We teched just behind TKO at one of the tournaments, and I think the only reason they made it was that the inspector couldn't figure out how to lift up a tracked vehicle.