motor stall current vs Victor ratings

[JBotAlan]

Originally Posted by dawilliams

Thank you all for your replies. This is certainly a credit to the FIRST gracious professionalism creed.

Well, the official hint has been released, so traffic here is picking up.

Originally Posted by dawilliams

To my thinking, this means robots pushing against each other won't be able to move each other. Thus more likely to stall the motor. Even geared down, if you push against the side of the opponent, you won't be able to move it, and that is still a stalled motor.

Two things:
1) the drivers are trained not to keep pushing if we're not moving--that would release magic smoke for sure if the wheels weren't slipping which brings me to:
2) our wheels start to slip when pushing against something relatively static at somewhere around half power, so our motors don't stall unless the driver stalls them on purpose (holds them at quarter power for a long time). We still have a strong pushing force; ask anyone who has played against us.

Originally Posted by dawilliams

So do you suggest a single Victor 884 for one of these large motors, or two in parallel for each motor, each with an independent 40A circuit breaker?

At first, I thought that having two victors on one motor was against the rules, but I re-read last year's rules and the only slightly relevant rule is <R86> in section 5:

Originally Posted by 2006 rules

<R86> No more than one motor may be connected to each Speed Controller.

That doesn't prohibit two Victors on one motor. However, I can see this being frowned upon during inspection. One victor is all that's needed to white smoke a motor; two seem like they would cause problems for sure. I just don't see the need for that much power. I don't think we've ever tripped a breaker. Just plan for the wheels to start slipping just as the motors start to stall.

JBot