Re: Victor 888: Upgrade to the Victor 884
 

The window motor thermal shut down with the locking pins removed and a jag was only seen when used in a positioning application controlled by a PID. We used the window motors for our swerve steering - 4 wheel independent continuous rotation. With the jag we had intermittent thermal shut down with the jag. We switched to victors and had no more problems even with extended run times during practices in a hot building in the summer. We have used the window motors in other non - positional applications and not had problems with the jags. Of course if the window motor is over loaded it will shut down with any controller. It will live to run again. For what ever the reason jags and window motor in positional applications is probably not a good idea. We have used the banesbot motor and transmission for 2011 and 2012 avoiding this problem.
Did you find that the output of the Talon was linear or did you have correct it in software?
There have been many versions of the jag. I'm almost certain one version used lock anti phase. If I remember right they have gone from a high side switcher to locked anti phase to the current low side switching.
The manual states the pulse as .9 to 2 ms is this a typo? Should it be 1 to 2 ms and will use the victor motor routines for programming?
Our team has a problem of marathon diver practice . A battery change is not a cool down period. If we end up using Talons they will have fans.
Another motor controller option. I like options. Thanks for the attempt to support First. Have they given any hint of the Talons legality for 2013?

Re: Victor 888: Upgrade to the Victor 884
 

[quote=Gdeaver;1187367]The window motor thermal shut down with the locking pins removed and a jag was only seen when used in a positioning application controlled by a PID. We used the window motors for our swerve steering - 4 wheel independent continuous rotation. With the jag we had intermittent thermal shut down with the jag. We switched to victors and had no more problems even with extended run times during practices in a hot building in the summer. We have used the window motors in other non - positional applications and not had problems with the jags. Of course if the window motor is over loaded it will shut down with any controller. It will live to run again. For what ever the reason jags and window motor in positional applications is probably not a good idea. We have used the banesbot motor and transmission for 2011 and 2012 avoiding this problem.

The output duty cycle is scaled linearly to the input, no additional math was needed to obtain a linear output.

The FRC version of the Jaguar has always been a high side switching synchronous sign-magnitude switcher. If there are any plots to prove otherwise I would like to see them.



This is not a typo. The Victor routines will work with the Talon. It is always a good idea to calibrate any motor controller however.

This is probably a good idea if you are performing back to back practices at your build facility. However in a competition it may not be necessary. If you notice the Talons thermal plots are on a 10 minute interval with a 30% duty cycle (3 minutes at specified current, 7 minutes off). This is on purpose as most matches have ~10 minute turn around. (start to start) Now keep in mind the matches only last 2 minutes and 15 seconds. So even if your robot slams into a wall at full speed at the beginning of auton and continues to run at full speed for the remainder of the match, you will not damage the Talon. With that said it can only help with performance to use the fan. Our rule of thumb is use the fan for any Talon on a 40 amp breaker. Of course this is only relevant if the Talon is deemed legal.

Re: Victor 888: Upgrade to the Victor 884
 

Black Jag. See Figure 4-4 on Page 19:

http://www.ti.com/lit/ug/spmu130c/spmu130c.pdf

Re: Victor 888: Upgrade to the Victor 884
 

As a point of clarification, all of the Victors since their creation (1999) have had conformal coating. The 884 has it and so does the 888 (and so did the 883, 885, etc.).

Re: Victor 888: Upgrade to the Victor 884
 

This is just a guess, but are the 888 and Talon related at all?

Re: Victor 888: Upgrade to the Victor 884
 

No. No relation other than the engineers that work on each are brothers.

However, IFI had no input on the Talon and CTRE had no input on the Victor 888.

Re: Victor 888: Upgrade to the Victor 884
 

Is there any particular benefit to using a Talon over a Victor or Jaguar? Am I correct in thinking it goes something like this:

Jaguar - Cheapest, bulkiest, most flexible functionality

Victor - Most expensive, smallest, most reliable

Talon - Somewhere in-between?

Re: Victor 888: Upgrade to the Victor 884
 

I believe the Talon is smaller then the victor, especially when it is run fan-less. Also the Talon is rated to handle more amps then the victor so victor vs talon reliability is up for question, no one has really tested the Talons like the victors.

Re: Victor 888: Upgrade to the Victor 884
 

Again, for a point of clarity the Victor is $89 so it is not the most expensive. Actually, it is the least expensive compared to the Talon on AM and the Jaguar on Mouser.

Re: Victor 888: Upgrade to the Victor 884
 

It looks like Vex's site is a bit misleading then.

http://www.vexrobotics.com/victor-speed-controller.html

It says "starting at $199.95" but then further down the page it lists "$89.99" as the actual starting price. Possibly because the $90 variant is out of stock. When I checked the first time I only noticed the "starting at" price.

Thanks for the correction.

Re: Victor 888: Upgrade to the Victor 884
 

This is interesting.
I never saw Mike talk about it at all when I saw the Talon, but this alone would make me choose this over the current 884s, even with the price difference. What about the 888's?
We've had instances with failed Jags before and never went back to them, other than a few robot functions for "smoother" output. The Victors size and reliabilty are so much better, other than the occasional poor connection with the PWM input.

Re: Victor 888: Upgrade to the Victor 884
 

It's my understanding that the only difference between a 884 and a 888 is that the out put has been made linear. If you have gown to love the Victors the 888 is the same only one little issue has been fixed. Interesting that this year we lost 2 884's however these were very old units that had been abused on many other robots and a ball lift jam finally killed them. The victors have proven reliable.

Re: Victor 888: Upgrade to the Victor 884
 

As another alternative, I would like to see these used. They are definitely a cheaper alternative:
http://www.canakit.com/50a-dc-pwm-mo...ontroller.html
Especially if you buy in bulk here (10+):
https://www.sparkfun.com/products/9668?

Also, to whom mentioned a lower amp version, they sell a 30A that is just slightly more that 1/2 the price:
http://www.canakit.com/30a-motor-spe...oller-pwm.html

Re: Victor 888: Upgrade to the Victor 884
 

Since those don't accept a servo style PWM input, what would you use them for in a FIRST robot?

Re: Victor 888: Upgrade to the Victor 884
 

Those only control speed, not direction. They also have an inappropriately high minimum voltage, and include knobs. I'll stick with the existing options.