[Mike Betts]

Tristan,

Concerning electromagnets, the GDC has been slow to make a definitive, clear ruling. As Al put it, what follows is my personal viewpoint...

A very popular electric solenoid actuator is a hinged clapper design. This is a ferrous core electromagnet with a spring loaded ferrous plate hinged at one end. Applying power to the electromagnet causes the plate to clap to the magnet and deflects the spring. When the EM is de-energized, the spring moves the clapper away from the EM.

Electric solenoid actuators are not allowed as per <R53>.

Many of the designs I have read about sound like the team has made their own ESA and are calling it a magnetic lock. This would not be allowed under this year's rules.

Concerning powered up robots. Al is 100% correct. The beginning of the inspection process is done with the battery removed...

My last point is safety. The idea that unpowering a robot, intentionally or unintentionally that causes a mechanism to deploy is just not safe.

Bottom line: While EMs are being allowed by the GDC, I can not envision an non-trivial, EM system that could be legally used on this year's robot.

IMHO, the GDC has dug a hole and will have to enlighten us further...

Regards,

Mike