Wiring Question
 

Hello i'm Phuc from team 4229. We are using actuators this year and ran into a problem of sorts with getting the actuators to run at the same speed. Does anyone know if it is against the rules to hook up two motors to the same jaguar or talon? I tried looking through the rule book but couldn't find anything about this. Thanks.

Re: Wiring Question
 

See rule R42 and Table 4-4 in the Game Manual.
It depends on the type of motor.

If you are using PWM, you can use a splitter cable to send the same signal to two motor controllers.
If you are using CAN, you can set one motor controller to follow the other.

Re: Wiring Question
 

Be sure to check that the amperage that the motors would pull does not exceed the potential output of the jags.

Re: Wiring Question
 

The problem is more likely that the actuators are responding differently to the same input; if this is the case, putting both of them on the same controller wouldn't help. If you really need the two actuators to move in sync, there are two basic solutions:

1. Hardware. Create a linkage such that the two actuators must always be at the same locations. This would not necessarily need to be as robust as if you were trying to drive things with just one actuator, but it must be good enough to equalize the differences.
2. Feedback sensors. Whether encoders or string potentiometers, put a sensor on each actuator and adjust the speeds to each so that they move together.

Re: Wiring Question
 

R42 clearly covers this topic. "Each power regulating device may control electrical loads per Table 4-4. Unless otherwise noted, each power regulating device may control one and only one electrical load."

Using talon or jag is not one of the exceptions.

Re: Wiring Question
 

According to R42 (second row of table), the following motors may be used with "Up to 2 per controller":

• Automotive Window/Door/Windshield
• Wiper/Seat Motors
• AndyMark PG
• Bosch Motor
• Snow-Blower Motor
• Denso Throttle Control

The list of controllers is R41 (A), and includes both talon, R41(A)(B); and jag, R41(A)(A).

Just use 2 talons/jaguars/victors but connect them with one spit pwm cable.

Re: Wiring Question
 

And what are we supposed to assume if our motor doesn't fall into one of those categories? Why doesn't FIRST simply state current or power limitations?

Re: Wiring Question
 

Read Rule R18 (emphasis mine):
The only motors and actuators permitted on 2015 FRC ROBOTS include the following...

If it isn't in the list, you aren't allowed to use it at all.

Re: Wiring Question
 

Yikes, so this part is illegal?

http://www.progressiveautomations.co...4sec-p-35.aspx

If I'm reading this correctly, we're in pretty big trouble.

Re: Wiring Question
 

the motor on that actuator looks a lot like a CIM. If you can take a legal CIM and stick it on that actuator you are back in action.
The restriction is on the motors we can use not what they are connected to.

Re: Wiring Question
 

Many teams have used such COTS linear actuators by replacing the actual motor with one of the motors allowed. In effect, they use the "gearbox" portion of the actuator with an allowed motor. See R18 for the full list - the list above is just the ones which can be duplexed on a single controller. The key things you're going to need to match are shaft, torque, and speed. If you then have several matches, look at mounting options.

Re: Wiring Question
 

You might need to replace the motor with another legal one, like a CIM or MiniCIM.

Is your team going to be at one of the week-0 scrimmages this weekend? If you let me know which one, I can try to stop by to help at some point and make sure it's legal!

Re: Wiring Question
 

We'll be at the week 0 event at Central High School in Saint Paul

Re: Wiring Question
 

Great! Do what you can to make sure it's legal and functional this week, I'll stop by there on my way down to Simley and look for you guys between 8 and 8:30 Saturday morning. Get there nice and early!