Can you begin the game with a tensioned rope/string?

[Clequis]

I am building a device that picks up the ball whch involves using a winch-like thing involving a tensioned rope. My coach says it should be fine but a senior team member says such a setup is not allowed at the beginning of a match. Our coach can sometimes mix up the rules a bit so I just wanted to make sure I wasn't doing anything illegal.

[Joe Ross]

See R34.

[SenorZ]

R34
Non-electrical sources of energy used by the ROBOT, (i.e., stored at the start of a MATCH), shall come only from the following sources:

compressed air stored in the pneumatic system that is legal per R79 and R80,
a change in the altitude of the ROBOT center of gravity, and
storage achieved by deformation of ROBOT parts.

I did a quick check of the Q&A (https://frc-qa.usfirst.org/Questions.php) and couldn't find anything expressly prohibiting what you mention. But It was a QUICK look. Generally, if it is considered unsafe it won't be allowed. So don't make something that seems unsafe... or better yet, submit a Question to the Q&A.

[pntbll1313]

In general yes. R34 states that it is legal to store energy before the match in the form of "deformed robot parts", in your case a stretched rope. Make sure that whatever you do is safe because anything deemed unsafe will not be allowed on the field.

[SpongeBobby]

Is a tensioned rope the same as tensioned tubing or spring? One could claim rope, tubing, spring etc. is a robot part that is deformed. but is the rule intended for intentionally deformed or accidentally deformed?

My interpretation is deformed robot part is a part not originally designed to provide tension. i.e a bent chassis rail which if taken apart may spring out of place - thus has to be tensioned to be reinstalled.

My assumption is any tensioned catapult created with tubing, rope, springs, etc. will be illegal at star.

any thoughts?

[dellagd]

I think its pretty clear. Energy can be stored on the robot by deformation of parts, like you said with tubing, rope, springs, etc. Regardless of the wording of the rule, people have been using tensioned items to store energy at match start for years and the rule hasn't changed.

To answer your question: Is a tensioned rope the same as tensioned tubing or spring? Yes, it is. The rule states nothing of your "usage" of said energy or why its there.