Gas Shocks not allowed?
 

Do the rules this year prevent the use of gas shocks as a form of stored energy?

It appears that the following rules make them illegal to use. Am I reading this correctly?

G03 - design is unsafe if motion can not be stopped by drivers

R37 -
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:
A. compressed air stored in the pneumatic system,
B. a change in the altitude of the ROBOT center of gravity, and
C. storage achieved by deformation of ROBOT parts.

R78.B - Closed-loop COTS pneumatic (gas) shocks not considered part of pneumatic system

Re: Gas Shocks not allowed?
 

G03 probably doesn't really need to be taken into account for most designs. Using gas shocks to counterbalance an arm, for example, still gives the drivers control over the arm itself. Look at the safety aspect of the design, and ask yourself what would happen if the shocks activate while a persons arm or finger was in the way. If the answer is "bad stuff", you might have a problem.

A closed loop gas shock would indicate that the entire gas shock, including the gas inside of it, was a robot part. As such, R37 allows them, as you are deforming the gas (compressing it) to provide the energy.

R78B is simply excluding gas shocks from the pneumatic rules. Specifically, the pressure rating rules. Gas shocks are designed to the proper ratings for their internal pressure based on the actual movement and compression seen in the shock. This could be less then the 125 PSI required by R76.

Re: Gas Shocks not allowed?
 

The shocks can be legal, if your design keeps them safe. I don't know your design, so I can't answer with respect to G03.

The blue box from which you quoted R78-B says "The following devices are not considered pneumatic devices and are not subject to pneumatic rules (though they must satisfy all other rules)...". So, the shock is just another robot part.

If you want to start with the shock in a compressed state, that would be allowed per R37-C (assuming all other rules, especially safety, have been met).

Summary: No, the rules do not prevent the use of gas shocks, IMO. But safety is key, and is likely of concern here.

Re: Gas Shocks not allowed?
 

Thanks for the feed back. We planned on using gas shocks in a climbing mechanism. The shocks would be compressed at the start of the match and driver would press a button that releases a latch that allows the gas shock to extend and push a lever or cable to pull the robot up the tower. Once button is pushed, motion of the gas shock would only stop at the end of extension.

Re: Gas Shocks not allowed?
 

You may need to convince the inspectors that this is safe. Which starts by designing the mechanism such that you believe it truly is safe.

Re: Gas Shocks not allowed?
 

Do realize this is exactly the same if you have an energized valve on an pneumatic cylinder. When denergized at the end of the match, the cylinder will move to its off state.

Re: Gas Shocks not allowed?
 

Would it be consider safe if the gas shocks were in a relaxed/extended position (eg. no stored energy) at the start of the match and during match play they were compressed?

Re: Gas Shocks not allowed?
 

The shocks could start the match in either extend or retracted position. Just like a spring. Safe or not is a different discussion & is dependent on the design.

Re: Gas Shocks not allowed?
 

In 2010, team 67 had a rube-goldberg hanging mechanism that was powered off of several gas springs. Rule S01 in 2010 was very similar to S03 this year, but 67 went on to win the championship.

Re: Gas Shocks not allowed?
 

If the shocks are compressed after starting the match, perhaps that means the user has more control over them, which would make it easier to make it safe (and to show the inspectors that it is safe).

Re: Gas Shocks not allowed?
 

As others have stated, they are just "robot parts". We've used them before as well.

If it is in a collapsed state (stored energy), I'd recommend using a gate latch or other locking mechanism with a safety pin and big REMOVE BEFORE FLIGHT safety banner that you take off on the field.