Posted by Chris, Coach on team #308, Walled Lake Monster, from Walled Lake Schools and TRW Automotive Electronics.
Posted on 4/30/99 9:40 PM MST
In Reply to: Re: Check this out posted by Dave on 4/30/99 8:27 PM MST:
I want to add to what Dave said.
We built a very robust arm for one main reason: simplicity of design. Why should we design a pole grabber, something to keep a basket down, a floppy-picker-upper, a robot pusher, and a robot puller with different mechanisms? All of this functionality could be incorporated in one arm, if it is made robust enough. This is what we chose to do. We got all of that functionality with only one motor and one air cylinder. It took other teams up to 4 motors to get that functionality.
-Chris
: Hey,
:
: Well, my team has one of those robust arms that could be used for many purposes, several of which could be used to hold down robots and pull them/the puck. In one match when we were against team 309 and the hot bot, we failed to gain control of the puck, so we went after the floppy carrier and held his basket down. Now, by the end of the match, his basket was pretty mangled, but not by us. After we had hooked 309’s basket, we had formed a T with us being the bottom part of the T. 309 preceded to run and manuver, but I was able to keep up with him. One manuver put us right behind him, which twisted his basket and our arm. With about 10 secoends left to go, they managed to get away, but were re-hooked as they were driving away as I tried to pull them back, which resulted in the tipping over of 309, not intentally.
: The point of all of that was to show that alot of the times damage caused by such arms is not always caused by the team with the arm, but the robot being effected by the arm. In this case, 309 could have tried to lower their basket since they were trying to put it up for the entire time they were hooked, or simply sit still. I know most people will look at those suggestions and think that they are very impractical, but look at the options, you can either move away from the robot that poses a threat to you, or just sit there and not risk killing your machine. In the case of 309, they would have retained all of their floppies instead of tipping and loosing several of their floppies. I know that there is a chance that you can get away, such as we did in the match before. An immobile robot hooked us and was pulled over by his own hook in our attempt to get away, but with getting our own robot damaged.
: Not all of time is it the robot with the arm’s fault. Many times accidents like that can be prevented, and if you don’t try to prevent them, you should be ready to accept the risks involved with it, such as we did.
: Dave
:
: : I am quoting the rules here, ‘intentional tipping is not in the spirit of FIRST’. If you design a robust arm which can tip and destroy other people’s baskets, then you are not in alignment with the spirit of FIRST. Think about it, how would you draw the line on a mechanism? We were contemplating putting a ‘stabilizer’ on our robot which would retract. It might also get under another teams robot and tip it over when we lifted it back up.
: : My interpretation of the intent of the rules was that if a robot fell over as another team was trying to climb the puck then OK. But if a team used its’ arm to intentionally tip over another robot then that’s not OK. I think we need some clarification form FIRST on this. It seems that at some regionals the refs were DQing teams which flipped other robots, well they didn’t in Florida, why?
: : Let me pose this question: how many teams did you see with an arm which could be used to tip over another robot? Most teams probably thought that a robust arm would be useless for floppy raising, and obviously a robust arm would have another intended purpose. (Floppies aren’t that heavy). Let’s get real if you had a robust arm, and you pushed on another robots’ high point, you are intentionally tipping it. As was explained, if you were battling for the puck, and one of the robots fell as a result, that would be OK.
: : I take that to mean that if you tip over another robot to get on the puck you violate the tipping rule. My girlfriend who is relatively unaware of the fine points of the contest, could not believe that the robots were being pulled over and ripped apart at the nationals. In one match that we were in, the opposing alliance reached out with its’ floppy picker and pulled our partners’ robot off the puck by its’ basket. Then kept pulling until the entire assembly was mangled. I have a photo of the aftermath if anyone is interested.
: :
: : 2 cents
: : Tom Wible