Centrifugal Arm Claw

[farmersvilleRob]

Originally Posted by EricH

There is one thing I'd be worried about, if my interpretation of this setup is correct (which it may not be).

Am I right in assuming that the claw(s) in question will be mounted on an arm, the entirety of which will be spinning at some speed sufficient to launch a ball if the claw holding said ball is opened, at some point during a match?

If I'm not right in that assumption, then you can ignore what I'm about to say. If I'm right, then your servos are going to be in a lot of trouble, whether they're servos or some other motor. You have them out at the end of a rapidly rotating arm, so they have to be mounted securely. However, I am confident that that is doable.

What concerns me, if the assumption is correct, is: I think you will need either a metric ton of extra wire, a slipring, or some other linkage to get the servo power out to the servo. You'll be winding up wire and possibly pulling and damaging connections, or having to reverse, otherwise. I would strongly suggest looking into sliprings for PWM (or whatever wire you end up using) to avoid this problem. Sliprings of appropriate gauge are legal per [R44] (this for those who were around when they weren't). Or an alternative linkage for claw release that doesn't involve the servo going around and around.

Again, this is only if I'm right about the intent of this arm design. If I'm wrong about that, then mea culpa for assuming something that wasn't clear.


The other thing I could say, but at this point I'm willing to bet that it could be done: I think the entire system is too complicated for any team, let alone a rookie team. However, that is for the team to decide, and they obviously have.

Well we were thinking of leaving a lot of slack in the wire and either having the robot pre -wind backwards or after autonomous (our team is heavy programming) we would let it reverse while it it moving which isn't that big a problem. As for damaging wires, we were going to at least hook the servo cable extenders at the weak points just in case it somehow gets out of hand then the break happens where it is designed to break.

We looked through the rules and it says that the actuators can't be changed under x, x and x, but we might pose a question to the GDC because it says in the blue box about it being a rule so teams can't get more power, but ours is just for functionality.