Victor and Spike in same circuit?

[phillutz]

We have an arm that "back-drives" when a tetra is on the arm and the motor is neutral.
The arm is on a Victor to provide speed control.
A spike would operate the arm too fast.

Can we wire a spike and a victor to the same motor?
Looking to operate it as follows

1. Raise Arm. (Victor controlling speed, spike controlling nothing really passing voltage through)
2. Arm Stopped. (Victor to neutral, spike to brake (rev & fwd = 1))
3. Lower Arm (sam as raise just other direction)

Is this legal?
Would it work?
Any other options we might try?

Thanks in advance,

Phil

[Mr. Lim]

Originally Posted by phillutz

We have an arm that "back-drives" when a tetra is on the arm and the motor is neutral.
The arm is on a Victor to provide speed control.
A spike would operate the arm too fast.

Can we wire a spike and a victor to the same motor?
Looking to operate it as follows

1. Raise Arm. (Victor controlling speed, spike controlling nothing really passing voltage through)
2. Arm Stopped. (Victor to neutral, spike to brake (rev & fwd = 1))
3. Lower Arm (sam as raise just other direction)

Is this legal?
Would it work?
Any other options we might try?

Thanks in advance,

Phil

Is setting the Victor's jumper to "Brake Mode" (Jumper pins A and B right on the Victor) not providing enough backdrive resistance?

In our team's experience, setting the Victors to Brake Mode behaves very simliar to shorting the motor leads in neutral, and it's all done automatically for you.

If it doesn't provide enough backdrive resistance, you may need a mechanical solution as running your motors at stall to keep it stationary isn't a viable option.

-SlimBoJones...

[Matt Leese]

Originally Posted by phillutz

We have an arm that "back-drives" when a tetra is on the arm and the motor is neutral.
The arm is on a Victor to provide speed control.
A spike would operate the arm too fast.

Can we wire a spike and a victor to the same motor?
Looking to operate it as follows

1. Raise Arm. (Victor controlling speed, spike controlling nothing really passing voltage through)
2. Arm Stopped. (Victor to neutral, spike to brake (rev & fwd = 1))
3. Lower Arm (sam as raise just other direction)

Is this legal?
Would it work?
Any other options we might try?

Thanks in advance,

Phil

No I don't think it's legal. That said, you can try setting the brake mode on the speed controller. If that also doesn't work, you have two choices: one is to try and create a closed loop system through programming to hold the arm steady. The other is to redesign your arm systems such that you get more torque out of your system. You may just be overloading the motor.

Matt

[phillutz]

We already tried the brake mode on the victor. No luck.
I guess 8-11 pounds is too heavy.
No stalling the motor (pwm = deadpan+2) is not a happy solution.

Okay. Mechanical it is.
Another PWM, Servo and a Bar.
(screwdriver in sprocket (ewww) solution.)

Thanks,

Phil

[zdeswarte]

I don't think you can because each victor and each spike needs their own fuses. You could throw some parallels in there but that would screw up all the voltage calculations and stuff; the judges might not like that a whole lot, either. I would say just use the victor unless breaking is that important...