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CDH Jeff
01-19-2009, 01:29 PM
Is there a specific height off the ground that parts of the robot have to be, other than the wheels? Or can something like, say, a ramp touch the floor?

EricH
01-19-2009, 01:55 PM
Is there a specific height off the ground that parts of the robot have to be, other than the wheels? Or can something like, say, a ramp touch the floor?
The rulings on Q&A seem to indicate that the only reason something can touch the floor is for feedback, and even then, it's limited. If you put a ramp on the floor, you'll be called on <R06>.

As for specific heights, the bumpers have to be in the bumper zone (Section 8.2) and the trailer hitch has to be at a certain height.

Bongle
01-19-2009, 02:03 PM
The rulings on Q&A seem to indicate that the only reason something can touch the floor is for feedback, and even then, it's limited. If you put a ramp on the floor, you'll be called on <R06>.


My week-old QA interpretation was that anything you want can touch the floor, so long as it does not provide sufficient drag or thrust to affect the low-friction dynamic. If you coated the floor-contacting portion of your ramp with rover-wheel material, then it would certainly not provide any traction or braking beyond what you could expect with the wheels.

edit: I can't find the QA response that I had justified that in my mind with, ignore me until I find it.
edit2: Here's (http://forums.usfirst.org/showthread.php?t=10943) the QA response, which gives a pretty broad ruling:
1. Other parts of the Robot may contact the floor, as long as the part does not provide any traction for the Robot.

Daniel_LaFleur
01-19-2009, 02:03 PM
Is there a specific height off the ground that parts of the robot have to be, other than the wheels? Or can something like, say, a ramp touch the floor?

There is no specific height that the robot must be (other than Erics points). Anything touching the floor that could be considered a traction device (even if it produces very little to no traction) will be cause for the inspectors to look closer and possibly fail your robot at inspection.

Between the regolith sheets (at the Kickoff in Manchester) there were small ridges. I'd suggest at least an 1/8" clearence for any non wheel part.

EricH
01-19-2009, 02:14 PM
My week-old QA interpretation was that anything you want can touch the floor, so long as it does not provide sufficient drag or thrust to affect the low-friction dynamic. If you coated the floor-contacting portion of your ramp with rover-wheel material, then it would certainly not provide any traction or braking beyond what you could expect with the wheels.

edit: I can't find the QA response that I had justified that in my mind with, ignore me until I find it.
edit2: Here's (http://forums.usfirst.org/showthread.php?t=10943) the QA response, which gives a pretty broad ruling:You might read the most recent batch.

For example, there's this one (http://forums.usfirst.org/showthread.php?t=11255), which pretty much bans slick balancing items, even if they won't affect the CoF.

There's also this one (http://forums.usfirst.org/showthread.php?t=11264), which effectively rules that you MUST use the Rover Wheels for traction--having the same material on something else is illegal if it's used for traction.

They've tightened up a little bit. It's not going to affect many designs, I don't think, but it's enough to affect your interpretation a bit.

Al Skierkiewicz
01-21-2009, 01:58 PM
Jeff,
There are a few rules that come into play here, but the test will be if the device contacting the floor provides traction or braking (more than 5% in any direction) in addition to the wheels provided and that said device does not damage the playing field surface. That second one is far easier to determine. I am guessing you think that that a ball chute that follows the floor is needed to pick up balls. If you were to investigate a little further, I think you would find that the ball diameter is sufficient to allow pickup without touching the floor.