Jaguar vs Jaguar CAN vs Victor vs Talon. whats the difference?

[Mr V]

Originally Posted by Jon Stratis

It's similar to what the Fighting Pi did - run the motor with a load on it, and see what happens. While they used a window motor (I think), we're running ours with a CIM motor, and we're applying a load by coupling that to another CIM motor that's hooked up to a Victor in break mode.

No need to hook the driven CIM up to a Victor in brake mode, connecting the wires together will have the exact same effect.

[nathan_hui]

Wouldn't placing a resistor across the leads create a poor man's dynamometer?

[Richard Wallace]

That's basically what Mike Copioli (developer of the Talon) did to create his test rig. You can see his results in the Talon doc available on the Cross The Road Electronics website.

I think the resistor value Mike used was zero Ohm -- i.e., he shorted the leads of one CIM motor on a CIMPle box, and drove the other CIM motor using the Talon.

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Edit: Mike also did some testing with infinite Ohms (open circuit) on the leads of the test rig motor, to check linearity of the speed response vs. input pulse width. This is indeed a "poor man's" version of the testing that Ether did later using a Magtrol dynamometer in my lab at Whirlpool.

You could use other values of resistance across the test motor leads; i.e., more than zero and less than infinity, but please check that the rating of the resistor is enough for the power the motor controller will be supplying.

[Mr V]

Originally Posted by nathan_hui

Wouldn't placing a resistor across the leads create a poor man's dynamometer?

If you want less load, then yes put a resistor (that can handle the current) across the leads, but if you want maximum load connect the leads together.

[dellagd]

To get back to the oigional question, we on 2607 like to use CAN for our motor controllers. CAN allows you to actually get live stats from the Jaguars as they are running, which was actually a unique aspect of our robot last year. Our bridge tipper (Bridginator) was powered by a plastic gearbox to a banebots motor (I think it was banebots). Anyway, if we flung the arm down at full speed, the plastic would break. But, if we hit the bridge at half speed and THEN increased to full power we could crush any ball that was beneath the bridge and still get on.

Being on Controls, we made the code to poll for the arm's motor amperage draw, a stat available over can. When the amperage spiked (e.g. hitting the bridge and the arm stopping) the motor was increased to full power.

So dont knock CAN till you try it! It can be quite useful

Though, it is a more complex system with more protocol to get from set motor speed to motor driving, which makes it a little more prone to problems. Just test it out and see if you like it!

[Ether]

You could achieve the same thing without CAN by using a micro switch. Yes, there are ways to mount the switch so it doesn't get damaged.

[dellagd]

Originally Posted by Ether

You could achieve the same thing without CAN by using a micro switch. Yes, there are ways to mount the switch so it doesn't get damaged.

There's many ways to do lots of things on a robot. I was simply saying it is an advantage of using CAN

[Joe Ross]

When used with the cRIO control system, the CAN Jaguar will have the highest resolution, followed by the the Jaguar, then the Victor/Talon.

[Ether]

Originally Posted by dellagd

There's many ways to do lots of things on a robot. I was simply saying it is an advantage of using CAN

My point was not clearly stated. There are advantages to using CAN that cannot be easily replicated if not using CAN. Listing a couple of those would bolster your argument.