Clutch system

[JB1357]

Originally Posted by martin417

Tanner,

I agree that the Q&A answers have been vague, but it looks to me like they are saying that if something moves by electromagnetism, and it's not part of a solenoid valve, or a motor provided in the kit, then it is illegal. I realize that the movement in the clutch is very small, but if they intended to allow some movement, they would have specified a maximum. By not doing so, they specified a maximum of zero inches.

All of the above is my opinion, and has no real meaning in the greater scheme of FIRST.

Sorry to go a little off-topic, but are you saying an electromagnet is illegal?

Thanks

[Alan Anderson]

Originally Posted by JB1357

Sorry to go a little off-topic, but are you saying an electromagnet is illegal?

The GDC answer indicates that using an electromagnet to hold something in place is permitted. Using one to move something is not. This fits well with Martin's "zero inches" interpretation.

[Tanner]

Thanks for helping clear a bit of it up. Though this answer by the GDC kinda affirms.

I still think that they (the GDC/FIRST) could still clear up what they mean by a electromagnetic solenoid as having none isn't exactly clear.

Not to be like a meanie or anything, but couldn't a motor be classified as a "electromagnetic solenoid" if it shifts the axel out/in for rotations? It's probably a extreme case, but still...

Not trying to spark anything up, just trying to make sense of confusion.

-Tanner

[Alan Anderson]

Originally Posted by Tanner

I still think that they (the GDC/FIRST) could still clear up what they mean by a electromagnetic solenoid as having none isn't exactly clear.

The intent is perfectly clear to me. I don't see the need for any more specific wording in the rules. If there were to be a strict definition of an "electric solenoid actuator" in the manual, you can be certain someone would find a device that doesn't meet the definition but really should have. The more painstaikingly detailed the rules are, the more loopholes people will find.

Not to be like a meanie or anything, but couldn't a motor be classified as a "electromagnetic solenoid" if it shifts the axel out/in for rotations? It's probably a extreme case, but still...

The permitted motors are itemized and granted legal status explicitly.

[engunneer]

Originally Posted by Tanner

Thanks for helping clear a bit of it up. Though this answer by the GDC kinda affirms.

I think the point they are trying to make in that answer is that you may design and build a clutch, or buy an existing clutch, provided that the actuation of the clutch uses a legal motor, servo, or pneumatic cylinder.

for example you could have two plates that move together when pushed by a cylinder (big bore, short stroke, most likely)

or two plates with slots, and a servo moves a connecting bar into the slots.

or you can use the ball-based torque clutch from an electric drill and actuate the tensioning mechanism with any of the legal actuators.

While it may seem simpler to say 'no electromagnetic clutches' or 'no clutches', the GDC is trying to limit you as little as possible by just saying 'no mechanisms with non KOP/R71/R72/servo actuators'

[Lil' Lavery]

I think the intent and interpretation of these rules are pretty clear and straightforward. Clutches are allowed, so long as they are actuated via legal means. Many teams have used dog gears (which are essentially a form of clutch) in transmissions for years, but they actuated them using legal pneumatics, motors, or servos.
There are no rules against electro-magnets, but an electro-magnet actuating something constitutes a servo and is thus illegal via the rules already stated. That seems pretty clear to me.