Quote:
|
Originally Posted by Joe Johnson
This foam WAS a great material but probably not for robots used in FIRST.
It was light and pretty tough but it really didn't like impact loads.
We used it on our arm in 1997. It was the best choice given the legal material selections available that year, but it was a constant source of worry and concern.
I think it totally exploded a round in NJ. I was not there, but the movie is impressive. We were fighting for position over the goal with another robot and then BAM! Catastrophic Failure and a shower of white foam rained down on the field. There is probably some pictures in the ChiefDelphi archive somewhere of that event. It was a spectacular failure.
At least it glued well ;-)
Bottom line: I was glad that it was taken out of the kit.
Joe J.
|
Actually rhoacell still is a great material, but you're right it probably doesn't belong on FIRST robots. It takes a bit of knowledge and experience to use composites of any kind properly. The failure you experienced sounds pretty typical of a composite structure. They tend to build up load and store energy with out a lot of deflection, until it is too much,
then it all comes out at once, in a variety of directions
There is a reason this
composite fabrication engineer built this year's arm out of
PVC.
