New Talon Speed Controller

[JesseK]

Given that a hot Talon gets de-soldered vice totally melting down I wonder if the reliability of the Talon goes down with age, particularly if a team decides to NOT use a fan along the way.

[sanddrag]

When designing robots, we also factor into the design offseason use such as parades and demos. With our most recent robot, we did a week-long demo doing light running continuously every day without pause except for battery changes (which were approximately once every hour). Victor 884s never gave a hiccup. I want to make sure we have the same success with whatever future controller we went with. It would be nice to not have fans, but but I suppose we could add them if needed.

[Ether]

Originally Posted by Tom Line

The Victor provided equally good results in both cases.

Tom, just to be clear what "both cases" means. Are you saying the Victor survived this test:

First, we ran without a fan. We connected 2 cims to the output, and 4 inputs from the PD board. We locked the drivetrain in place, and then started ramping up the voltage.

[Tom Line]

Originally Posted by Ether

Tom, just to be clear what "both cases" means. Are you saying the Victor survived this test:

I can see why that was a little confusing. I suppose I should have been more concise and listed it out in table form.

Test 1:
Talon with no fan.
Driving 2 stalled cims with 4 inputs from the PD board.
Fluke ammeter reporting amperage on the positive battery lead.
Died at 60 amps.
Root Cause: Temps were above 100 C, and the board desoldered.

Test 2:
Victor with fan.
Driving 2 stalled cims with 4 inputs from the PD board.
Fluke ammeter reporting amperage on the positive battery lead.
Ramped up to 80+ amps and the robot began turning off and on.
Ramped back to 80 amps and ran for about 30 seconds without a problem.

Test 3:
Talon with fan driving 2 stalled cims with 4 inputs from PD board.
Fluke ammeter reporting amperage.
Ramped to 80 amps without a problem, held at that point for 30 seconds without a problem.

Test 4: (verification of our fluke ammeter readings)
Talon with 1 stalled cim and 2 inputs from PD board
Inline datalogger ammeter plugged via USB to laptop.
Datalogger was placed on the positive lead from the PD board and fastened to the speed controller.
Ramped to 74 amps without a problem: above this the 40 amp breakers began resetting.

In each case with the fluke, we zeroed it when the robot was enabled with no pwm signal sent to the motor. The robot ran between 3-5 amps on the positive battery lead when enabled with all motors at rest.

[JB987]

Anybody out there comfortable with using a fan-less Talon for competition?

[Richard Wallace]

Originally Posted by JB987

Anybody out there comfortable with using a fan-less Talon for competition?

Not me. Not when fans are so cheap.

I want my drive team free to push their robot to its limits.

[sanddrag]

Originally Posted by Richard

Not me. Not when fans are so cheap.

I want my drive team free to push their robot to its limits.

So then what's the benefit over a Victor 888, which can be purchased for less cost? Just the fact that it isn't open for debris to fall inside?

[Richard Wallace]

Originally Posted by sanddrag

So then what's the benefit over a Victor 888, which can be purchased for less cost? Just the fact that it isn't open for debris to fall inside?

That, and better linearity. Talon linearity is almost like a Jaguar, Victor is not.

[cgmv123]

Originally Posted by JB987

Anybody out there comfortable with using a fan-less Talon for competition?

Based on what I've seen, I'd feel comfortable using it sans fan on anything that's not a CIM or Fisher-Price motor and/or isn't on a 40-amp circuit. I'd use a fan or Victor or Jaguar for everything else.

[Camren]

So at a recent off season competition our team had tested out the Talons and so I thought I would post a few notes.

- Friday we were practicing with Jags still attached, Saturday with Talons on we noticed a slight speed difference

- The Talons didn't heat up though its debatable to account this since the schedule was light weight

[CalTran]

Originally Posted by Camren

So at a recent off season competition our team had tested out the Talons and so I thought I would post a few notes.

- Friday we were practicing with Jags still attached, Saturday with Talons on we noticed a slight speed difference

For better or worse speed difference?

[Camren]

Originally Posted by CalTran

For better or worse speed difference?

For the better

[Ether]

Originally Posted by Camren

For the better

Could you please clarify what you mean by a "better speed difference"?

For example:

- faster speed for a given open-loop throttle setting

- more linear response to open-loop throttle commands

- more stable closed-loop speed control

- something else?

Also, did you measure it or is this a subjective judgement of the driver?

[Camren]

Originally Posted by Ether

Could you please clarify what you mean by a "better speed difference"?

For example:

- faster speed for a given open-loop throttle setting

- more linear response to open-loop throttle commands

- more stable closed-loop speed control

- something else?

Also, did you measure it or is this a subjective judgement of the driver?

This is a subjective judgement of the driver

- The stability of closed loop control is debatable due to the recent drive train change though open loop control was tested with both the Jags and Talons with the new drive train.

- The speed and agility on carpet with the Talons equaled the speed and agility off carpet with the Jaguars.

- Difference of response time between the two motor controllers were either subtle or not there.

[ehfeinberg]

Originally Posted by Richard Wallace

Jags have CAN now. Talons will have it later.

When exactly is later? And if we buy Talons now, will they be compatible with CAN once Talons support CAN?