Motor Switches

[Andrewpbhs]

Hey quick question, can the motor controllers handle 2 CIMS? or do we need one per motor?

[groves]

One Victor speed controller per cim whether it can handle it or not. thems the rules.

[JBotAlan]

Originally Posted by Andrewpbhs

Hey quick question, can the motor controllers handle 2 CIMS? or do we need one per motor?

I believe what you describe is legal; however, I know I wouldn't be comfortable with 2 CIMS to a Victor. I'll leave the technical discussion to the other members, but just out of curiosity, why do you want to do such a thing? Victors aren't that heavy, and I believe we received PWM splitter cables in the kit just so that you don't have to modify code to use 2-CIM transmissions...

Good luck
JBot

EDIT: Groves, can you cite me a rule? I see <R91> , but that's the opposite of what you are trying to prove:

<R91> Each motor, actuator, and compressor must be connected to one, and only one, speed controller or relay module.

[Rickertsen2]

Even if the rules allow, i wouldn't do it. Even if the victors could handle it, you would have to power the victor off a single fuse. That single fuse would be constantly blowing and would definately not be able to handle it.

[AV_guy007]

this question came up somewhere else on the forum recently but cant seem to find it

I believe <R91> can and should be interpreted to mean one victor per motor.

<R91> Each motor, actuator, and compressor must be connected to one, and only one, speed controller or relay module.

in my opinion I would not count a "shared" victor as one victor per rule <R91> technically I would count it as 1/2 victor because it is not devoted to a single motor. that might be stretching it a little but i don't think it is a good idea to attach multiple motors to one victor. when unsure air on the side of caution

[Hieb]

<QUOTE><R91> Each motor, actuator, and compressor must be connected to one, and only one, speed controller or relay module.</QUOTE>

Your 2 CIMs are 2 motors, thus you would need 2 speed controllers. How many motors you have feeding your transmission is irrelevant.

[dtengineering]

While you are required to have one Victor per CIM, if you have two CIM motors hooked up to one transmission you may... if you wish... use a PWM "Y" cable to connect both Victor speed controllers to the same PWM output on the robot controller.

Jason

[Gabe]

Our team can tell you from experience that they will make you do this. In 2005 we had to reorganize the wiring for four victors because the judges discovered that we were running two CIM's per Victor.

[mtaman02]

1 Victor Speed Controller to each Motor. I'm sure FIRST has it this way to save Teams money in having to buy replacements for blown Victors - A victor can only handle so much why stretch the limitation.

[Brian Mocci]

Although I would never advocate running more than 1 CIM per victor as you would be blowing fuses like its your job, Ruling <R91> does state that it is legal according to its current wording.

<R91> Each motor, actuator, and compressor must be connected to one, and only one, speed controller or relay module

In a scenario where there are two CIMS connected to one speed controller, the system would be considered legal as each motor is connected to one, albeit shared, speed controller. However, if the rule was written (Or interpreted) backwards, as one speed controller per motor this would be illegal.

Please correct me if I'm wrong here

[Al Skierkiewicz]

Just in case someone thinks this is still a good idea, the FETs in the speed controllers are good for 65 amps each. Times three, that is 195 amps on a good day at room temp. A Chalupa has a stall current of 129 amps so two would be 258 amps, more than 60 amps over max for the FETs. Goodbye little Victor! That is why the rule is written to use only one motor per Victor so there is no smoke obscurring views at events.

[sanddrag]

Originally Posted by Gabe

the judges discovered that we were running two CIM's per Victor.

I think you mean inspectors.

[Jared Russell]

Originally Posted by Al Skierkiewicz

Just in case someone thinks this is still a good idea, the FETs in the speed controllers are good for 65 amps each. Times three, that is 195 amps on a good day at room temp. A Chalupa has a stall current of 129 amps so two would be 258 amps, more than 60 amps over max for the FETs. Goodbye little Victor! That is why the rule is written to use only one motor per Victor so there is no smoke obscurring views at events.

Mmm...chalupas.