CIM/ Jag power help

[team3329]

Having some issues with Jag compatibility and our CIM motors. We are thinking of using a 4 wheel direct drive with mechanum wheels to test, but our Jags are running the motors slow on 3 and not at all on 1. Is it a power distribution problem?

[Ether]

Originally Posted by team3329

Having some issues with Jag compatibility and our CIM motors. We are thinking of using a 4 wheel direct drive with mechanum wheels to test, but our Jags are running the motors slow on 3 and not at all on 1. Is it a power distribution problem?

There's no "h" in mecanum.

Are you using PWM or CAN to command the Jags ?

[team3329]

PWM. What is CAN? We are extremely new to this. 2010 was our first year, and we pretty much followed the instruction manual and figured it out as we went. Not too familiar with terms yet....

[rahilm]

I would suggest just the basic diagnostics first:
Check your voltages in to the jags (should be >=12 with a charged battery)
Check voltages out from the jags (should be ~0 when joystick is 0, should be >=12 when full forward)

[Ether]

Originally Posted by rahilm

Check voltages out from the jags (should be ~0 when joystick is 0, should be >=12 when full forward)

There's a small ongoing discussion about this in another thread. So may I ask, have you personally actually done this ? If so, what type of meter* did you use and what range** did you set it for ?


* i.e. analog or digital or oscilloscope etc

** e.g. 0 to 15VDC or VAC etc

[Ether]

Originally Posted by team3329

PWM.

Have you looked at the Dashboard to confirm that your software is indeed commanding full throttle?

Have you measured the voltages at the Jag's output and power input at full throttle?

Have you measured the CIM's current at full throttle?

[rahilm]

Originally Posted by Ether

There's a small ongoing discussion about this in another thread. So may I ask, have you personally actually done this ? If so, what type of meter* did you use and what range** did you set it for ?


* i.e. analog or digital or oscilloscope etc

** e.g. 0 to 15VDC or VAC etc

Just a regular digital multimeter. We have checked this whenever we have trouble and this is the behavior we see. (The multimeter is autoranging, so not range setting)

[Ether]

Originally Posted by rahilm

Just a regular digital multimeter. We have checked this whenever we have trouble and this is the behavior we see. (The multimeter is autoranging, so not range setting)

Does the meter have a setting for selecting DC or AC? If so, what setting was it on?

You don't happen to remember the brand and model number by any chance, do you?

[rahilm]

Originally Posted by Ether

Does the meter have a setting for selecting DC or AC? If so, what setting was it on?

You don't happen to remember the brand and model number by any chance, do you?

Yeah, we set it on DC.
I know it was a Fluke brand, not sure about the model number though. I can get the model number and confirm the behavior tomorrow. Maybe hook it up to an oscilloscope too.

Edit: Looking at Fluke's website, I'm fairly certain it is the Fluke 114

[ErikRantapaa]

A scope certainly would be able to tell you if the Jag is trying to drive the motors correctly.

I think it would be helpful to have a hand-held PWM signal generator to be able to test Jags directly. Something like this:

http://www.rc-cam.com/servotst.htm

or this:

http://www.sentex.ca/~mec1995/gadgets/servo3.htm

Also, any hobby store should have something similar available. Google for "servo tester".

[Ether]

Originally Posted by ErikRantapaa

A scope certainly would be able to tell you if the Jag is trying to drive the motors correctly.

I think it would be helpful to have a hand-held PWM signal generator to be able to test Jags directly. Something like this:

http://www.rc-cam.com/servotst.htm

or this:

http://www.sentex.ca/~mec1995/gadgets/servo3.htm

Also, any hobby store should have something similar available. Google for "servo tester".

Both of those say they go from 1 to 2ms.

I think the default input PWM range for the Black Jag is 0.67 ms to 2.33 ms.

So those devices wouldn't drive a default-configured Black Jag's output to its full range.