Bridge material question

[davidrk13]

thank you

[davidrk13]

hey so i pretty much finished making the bridge and have some concerns.

1. is it alright to NOT include a pinch guard? whats the worst thatll happen?

2. the real field will be made out of a kind of plastic which has a different friction than plywood. is the frictional difference that great that lets say if the bot goes fine on the plywood bridge. that it wont go as smoothly on the real field or vice versa?

[Retired Starman]

Originally Posted by davidrk13

hey so i pretty much finished making the bridge and have some concerns.

1. is it alright to NOT include a pinch guard? whats the worst thatll happen?

2. the real field will be made out of a kind of plastic which has a different friction than plywood. is the frictional difference that great that lets say if the bot goes fine on the plywood bridge. that it wont go as smoothly on the real field or vice versa?

The competition field does not include the pinch guard, but it is good to have it on your practice bridge to keep people from getting their hands under the bridge. The worse that an happen might include having a finger cut off or some hand bones broken. This won't happen on the field since there won't be people getting their hands under the bridge. The most dangerous place is in the hinge assembly. A second danger point is right at the end of the bridge where the bridge meets the floor. If you don't want to build the entire guard, consider putting a guard over both sides of the hinge.

There is a significant difference between the slickness of a plywood bridge and one with polycarbonate on it. If you can't afford polycarbonate, consider something e styrene or acrylic which might bee a little less expensive but would be durable enough for practice.

Dr. Bob

Chairman's Award is not about building the robot. Every team builds a robot.

[davidrk13]

Originally Posted by Retired Starman

The competition field does not include the pinch guard, but it is good to have it on your practice bridge to keep people from getting their hands under the bridge. The worse that an happen might include having a finger cut off or some hand bones broken. This won't happen on the field since there won't be people getting their hands under the bridge. The most dangerous place is in the hinge assembly. A second danger point is right at the end of the bridge where the bridge meets the floor. If you don't want to build the entire guard, consider putting a guard over both sides of the hinge.

There is a significant difference between the slickness of a plywood bridge and one with polycarbonate on it. If you can't afford polycarbonate, consider something e styrene or acrylic which might bee a little less expensive but would be durable enough for practice.

Dr. Bob

Chairman's Award is not about building the robot. Every team builds a robot.

thank you very much retired starman just one question concerning the bridge. i already finished the plywood version of the bridge and the most i can do is to use a coating to try to mimic the slickness of the actual competition bridge what do u recommend i should get to coat the plywood to accomplish a like slickness to that of the polycarb?

[Phyrxes]

Originally Posted by IceStorm

Would you be able to provide the part number at mcmaster? I haven't went looking yet but know that there catalog is quite vast in what they carry.

8619K427 is the part number for the 48 inch by 48 inch by 1/16 of an inch thick smooth sheet in white.

http://www.usfirst.org/sites/default...amDrawings.pdf is the "low cost" (Read: lots of plywood and 2x4's field elements).