4.1.8.2 [R50] - Wait.. Wut? So I can run an RS775 or RS550 off a spike???

[fox46]

I am not sure if I am missing something here but rule 4.1.8.2 [R50] under Motors and Actuators states:

"a. Each CIM motor and Fisher-Price motor must be connected to one and only one approved speed controller. These motors must not be connected to relay modules"

What about all the other motors we can use? It seems to me that FIRST has made a massive oversight on this rule and that with the exception of maybe the BaneBots RS370 and smaller motors, that this rule should include all of the BaneBot motors (the RS550 is essentially a Fisher Price motor). What do people think?

Of course the fuses on the spikes will simply blow if you try to suck too much power from them but this still seems like a bad idea to allow teams the option of running RS775s and RS550 motors off spike modules.

[ebarker]

Take a 20 amp poly fuse, the same one that is in the PD board, and put it into the spike, replacing the blowable fuse that is already in the spike.

[Jeff Pahl]

Originally Posted by ebarker

Take a 20 amp poly fuse, the same one that is in the PD board, and put it into the spike, replacing the blowable fuse that is already in the spike.

That's only allowed for the air compressor.

Yes, the rules allow you to run those motors off a Spike Relay Module. Whether or not that is a sound engineering decision is left up to you.

[Al Skierkiewicz]

Watch for any team update that might modify R50.

[J.Warsoff]

We've used BaneBots motors before, and I do believe they are legal to use as long as they connected to only one speed controller.

But I agree with Al. To be safe, wait for an update before you make any final decisions.

[Tom Line]

I certainly hope they don't mess with this rule. The circuit breakers are there to protect the wire already for safety purposes.

We have picked motors for our robot and were very careful to determine which applications required variable and which were on spikes. That's because of the number of motors we'll end up using: we really don't want to break into a second digital side car, and one more victor/jag means we will.

*crosses fingers that they leave the rule as it stands*

[fox46]

I like the idea of being able to use spikes for low load items like the RS375 etc. because they are lighter and take up less realestate than Victors or Jaguars but I can see this rule causing some inexperienced teams headaches as they overload and end up with spikes popping fuses left, right and center. They will surely post on CD asking why this is happeneing and will have to spend valuable time reworking their electronics and code with a jaguar or victor to fix it. -Just watch

[Thad House]

I do not think they will change it because that same rule was in place last year with the same motors, but it was never changed.

[fox46]

I do not think they will change it because that same rule was in place last year with the same motors, but it was never changed.

Are you sure? I specifically remeber trying to build mecahnisms last year around what motors needed to be supplied by an ESC vs a Spike. Maybe I was just going on intuition or what I thought they had to be powered by- I can't remember.

[Thad House]

<R48> All electrical loads (motors, actuators, compressors) must be supplied by an approved power
regulating device (speed controller, relay module, or Digital Sidecar PWM port) that is
controlled by the cRIO-FRC on the ROBOT.
A. Each CIM motor and Fisher-Price motor must be connected to one and only one
approved speed controller. These motors must not be connected to relay modules.
B. Servos must be directly connected to the PWM ports on the Digital Sidecar. They must
not be connected to speed controllers or relay modules.
C. If used, the compressor must be connected to one and only one approved relay module.
D. Each other electrical load (motor or actuator) must be supplied by one and only one
approved speed controller, or one and only one relay module

That is from 2011.

Although I am going to say just because you can doesn't mean you should. We will be all of our big motors on jags or vics just for safety

[Al Skierkiewicz]

Guys,
I am not implying that the rule is going to change. I just want people to get used to looking for changes. Today is a Team Update day.

[EricH]

Originally Posted by Al Skierkiewicz

Guys,
I am not implying that the rule is going to change. I just want people to get used to looking for changes. Today is a Team Update day.

And so is Friday. TU#3 came out with no change to [R50].

[MrBasse]

We ran a 550 for our gripper last year through a drill clutch and used and abused it. We powered that through a spike and had no issues, just know its full throttle all the time and make sure that you use it in an application where control isn't incredibly important (i.e. a clutch) and there really is no issue.

[Jeff Pahl]

Originally Posted by MrBasse

We ran a 550 for our gripper last year through a drill clutch and used and abused it. We powered that through a spike and had no issues, just know its full throttle all the time and make sure that you use it in an application where control isn't incredibly important (i.e. a clutch) and there really is no issue.

Running it through a clutch so that the motor never stalls is one excellent example of a design that will allow you to run a "big" motor from a 20A fused circuit. If you use a 550 in a design that expects the motor to stall when it reaches the end of the range of motion, that fuse will blow.