[Joe Johnson]

Rule M11 (limiting stored energy in a spring at the start of a match to 20 ft-lbs) seems to dissallow the (historically) common practice of counterbalancing arms, baskets, etc.

For example, suppose a robot has a 10 lb gripper. If the way the arm stores at the beginning of the match puts it at the bottom of the box, the springs on the robot could only lift this gripper 2 ft before exceeding the 20 ft-lb limit.

Another example, the smallest gas spring sold by Small Parts Inc. puts out 60 lbs of force and has a stroke of 3.5 inches. Compressing this single spring would store almost 90% of the legal limit.

This does not seem reasonable.

This is a very significant limitation to a very important aspect of proper robot design (specifically, using springs to compensate for gravity effects of robot arms & mechanisms).

Counterbalance of robot arms is a "best practice" that is effectively forbidden by this rule.

Safety is an important aspect of robot design and springs can be dangerous if not designed properly, but lack of counterbalance can be dangerous as well.

Do others read the rule the same way as I do?

Thoughts?

Joe J.