utter confusion

Technical Motors
1

we have a sim motor hooked up to a conveyer belt system to pick up balls when it is directly connected to 12v battery it works fine… when we go through the jaguar it acts as though it needs more power. the jaguar shows a red blinking light while it runs, then the light goes steady and the motor stops running

2

How is the motor hooked to the conveyor system? Direct coupling, gearbox, chain and sprocket? What’s the ratio?

Oh, yeah: you kind of don’t want to run the motor directly from the battery. I think there’s some reason, but I can’t remember what right now.

Also, what’s the programming on the Jag?

3

It’s connected with belts, but as bighead said before, we ran it straight from the battery (the entire mechanism, belts and all) and it ran fine. This is the code:


if (stickL.GetTrigger())
	ballSucker.Set(-1.0);
else
	ballSucker.Set(0.0);

I tried swapping the PWM cable with the one for the wheels, and the code makes the wheels spin fine.

EDIT: We just tried disabling the watchdog, and that didn’t work either. The jaguar runs for a bit (slowly, not powerful enough to run the motor) and then stops.

4

A fast blinking red light on the Jaguar indicates that it is running in reverse at less than full power. This means that it is receiving a PWM signal that is less than the maximum value (in the negative direction).

When the light goes solid what color is it? A solid yellow light indicates that the Jaguar is receiving a neutral PWM signal. A solid red light indicates full-speed reverse. If the motor runs when the Jaguar is flashing red, but not when it is solid red there are two possibilities. The first possibility is that the motor is drawing too much current and tripping the breaker, you should be able to hear a clicking sound if this is the case. The other possibility is a hardware failure in the Jaguar.

Just to make sure, the Jaguar is connected to a 40A breaker on the Power Distribution Board right?

Ok, it looks like you posted your code while I was writing my post. If that code causes the Jaguar to have a flashing red light I recommend you calibrate the Jaguar using the procedure in the Getting Started Guide

EDIT: Code was posted while I was writing

5

So, it’s not the code. Therefore, I have the following questions:

  1. What’s the gear ratio? (If you don’t know, what gearbox are you using/what size are the pulleys?)
  2. What’s the breaker on the circuit?
  3. Is the Jag calibrated? (I’m guessing it is…)
  4. Are there any other variables that changed between tests? i.e., were there any additions, were both tests run with a fresh battery, etc.?
6

I remember having a similar problem where our shooter was unable to fire as far as it normally did, even when we ran it at full power.

Turns out the problem we had was that one of the programmers accidentally set one of the PWM outputs in the code to be set for a Victor, not a Jaguar. Right after we switched the code to what it was supposed to be, everything worked fine.

7

For all the gear ratio/mechanical questions:
We took a fresh battery and placed the wires from the motor DIRECTLY to the battery terminals. The motor spins and the entire mechanism works perfectly. I do not think the gear ratio or motor itself are the problem. We can do this again and again and it works, so we have not burnt out the motor or anything like that.

We just tried recalibrating, and it did not work :(. The breaker on the circuit is the same kind our wheels, 40A.

I changed the code to:

ballSucker.Set(stickL.GetY());

Full backward on the joystick makes the jaguar show a solid green light for about 1 second, then goes to solid red. When the joystick is forward, the light goes solid red. During the first second, the motor seems to be trying to turn, but after that it dies.

8

Just because the setup runs off of the battery does not mean that the issue is not mechanical.

The CIM motors can draw 133 Amps at stall and can still spin very fast when drawing much more current than can be provided when used in the typical robot setup. When drawing 80A the CIM can still spin at ~2150RPM.

9

Umm… a 40 A breaker will let a lot less current through than the 120A main breaker, which can be tripped by the battery. That’s a lot of current! That’s also a bit of power available that you can’t use.

It’s probably not the motor. Likewise, it’s probably not the Jag, unless it’s burned out. We’ll assume that that is not the case (for now), so let’s continue up the system.

Code: Probably not, unless it’s a Victor/Jag switch. We’ll assume it isn’t, for now.

That puts it in the gearing or the wiring/electronics.

Gearing: I’m asking because it takes more power to turn a lower ratio. If you gear the conveyor for speeds much faster than the motor, you’ll notice this quickly. So it takes more current, which you now can’t get. However, it sounds like your breakers aren’t tripping. Probably not the gearing.

Check your wiring in that circuit. You might have loose connections, which limit the flow of current. I remember troubleshooting a robot that was having trouble driving. The problem was traced to a loose wire in one of the drive slots (or was it a loose breaker? Doesn’t matter, I guess).

10

The gear ratio is 2:1. We are going to swap them now and see if it makes it work.

EDIT: It works perfectly! Thank you very much :slight_smile: