Maximum Number of Motors?

My team and I were trying to figure out the maximum number of motors allowed in this year’s FRC game. We couldn’t find it in the game manual. Do any of you know where I would find that number or is anyone able to just answer our question?

I believe (correct me if I’m wrong someone) the max amount of motors depends on what power distribution you use. With the CTRE PDP, there are 16 slots that could be used for motors, and with the new REV PDH, there are 20 slots for motors. Mind you, these can also be used for things like a limelight vision system

4 Likes

Yep, the only rules here is one motor per breaker and look at the rules for your particular PDP for max breaker sizes.

1 Like

Perfect, thank you so much!

1 Like

I would recommend doing a deep dive on section 9.5 in the game manual. The rules in it govern the electrical system on legal robots.

The maximum legal number wired-up, controlled motors is neither 16, nor 20. I leave it as an exercise to the reader to determine the actual number.

Keep in mind the battery cannot supply infinite current. Just because a configuration is legal does not imply it is functional.

7 Likes

And to you as well!

I’m going to need my SCUBA gear.

1 Like

Will do, thanks!

Don’t forget you are allowed to run some brushed motors in parallel. Hmm, I wonder about series connection???

Well, sure. You can run TWO bag motors off a single motor controller. And that gets you to 40.

2 Likes

The question really should be “should you?” rather than “can you?”…

2 Likes

QFT.
And you can put over a hundred throttle motors on your robot - as long as you don’t power most of them.

I think that depends on the interpretation of R503.

With the exception of servos, fans, or motors integral to sensors of COTS computing devices permitted in R501, each actuator must be controlled by a power regulating device.

It does not say

… each actuator which is powered must be controlled by a power regulating device.

2 Likes

According to Merriam Webster, an actuator is “one that actuates”.
Actuate is defined as: “to put into mechanical action or motion”

Unpowered motors don’t do this are are therefore not actuators.

Several other definitions actually discussed turning other forms of energy (e.g. electricity or air pressure) into mechanical energy.

Further, R501 says: “The only motors and actuators permitted include…”, which seems to imply that not all motors are actuators.

If it mattered (e.g. someone wanted to use a motor with an internal encoder purely as a sensor, a passively shorted motor as a brake, or a Dynamo as a hood ornament), this would be one for Q&A, and would involve R501 (definition of an actuator) as well.

Obligatory LRI-a-roo.

1 Like

I think that rather this implies not all actuators are motors. Electrical solenoid actuators stand out most clearly as an example of this, and your mention of converting other forms of energy solidifies my argument.

The inclusion of any part number in that list also suggests that such a part (unmodified except as permitted by R502) is, by the Game Manual’s standard, perpetually an actuator regardless of usage.

If we wanted to take this a step further, we could discuss the legality of a COTS motor sawed in half, and whether that is still an actuator.

This topic was automatically closed 365 days after the last reply. New replies are no longer allowed.