Drive with tallons
 

I wasn't sure if this should go here or under motors but here it goes. Tonight my team took inventory on all our parts in prep for kickoff and realized were almost out of usable jaguars. Usually we use jags for drive motors and victors for other motors. Online we noticed that tallons are cheaper than jags so is it a bad idea to use them for drivetrains?

Re: Drive with tallons
 

Talons are an excellent choice for speed controllers. I'd argue they're better than Jaguars if you aren't using CAN.

Re: Drive with tallons
 

Their compactness, linearity and reliability make them some of the best drivetrain speed controllers. 10/10 would use again.

Thanks guys. I wasn't sure if they were only usable on lower power motors like window motors

Re: Drive with tallons
 

Definitely agree with the above posts. We used talons for the first time last year (on just about every motor) and loved them, especially after having used all jags the previous year - the small footprint was amazing and they worked just as well as the jaguars.

Re: Drive with tallons
 

Look at the VEX Product Donation Voucher for this year. I believe there were some options for Jaguars in it. http://www.vexrobotics.com/vexpro/pdv-group.html

My opinion is to get Talons if you are not already invested in CAN with the Jags.

Here's another question. Would talons also replace victors? Or just jags? I'm not sure of we use can I'll have to ask a programmer

Re: Drive with tallons
 

You can use Talons with every motor except Window motors. The switching frequency will disrupt the window motor's locking pins (just like the Jaguar's similar switching frequency also messes with the locking pins.)

So stick with victors for window motors?

Re: Drive with tallons
 

All three can replace all three (Except for window motors, I learned that today). The only thing you need to be aware of is that to change from jags/victors to tallons you need to change the initialization in your code as well otherwise the output will get doubled. (40% --> 80%, 70% --> 100%). Jags and victors can be swapped without code changes.

Here's the 1 paragraph summary of the different speed controllers. Talons and jags are more linear, meaning that when you say "Speed controller give me 20%" it gives you closer to 20% than a victor would. This is only at low speeds though, above about 40% the difference is negligible. Talons are sealed so no peaky metal shavings get in them and fry them, however they will fry if you hook them up backwards because they have no reverse current protection. (on the plus side you can charge your batteries like this!) Jags can do CAN which can be used for cool features.

Re: Drive with tallons
 

Yes, sorry for not making that clear.

884's will definitely work, but I don't know how 888's will work since their switching frequency is slightly higher than the 888's.

Re: Drive with tallons
 

Note that all 3 speed controllers lack reverse current protection.

Re: Drive with tallons
 

Talons are sealed, so you can give a high five to the face with an arc-welder to metal dust and other debris that will murder your speed controllers so easily. Those small particles, though they seem harmless, will gather up, and work together to produce magic smoke! With the talons, you can say Bye-Bye to that!

Also, talons are passively cooled, because they have a shiny heat sink atop themselves.

Oh yeah. I forgot to mention that the talons are a much newer model, so the designers must have taken the flaws of the previous controllers and fix them in this. Otherwise, talons more-or-less behave like victors! I think that that is how you program them too!


---So the short answer is, Go for them! They will eradicate some of the team's headaches!

Quite some fluff in there^^:D

Re: Drive with tallons
 

I'm not sure what you're referring to by initialization. There are two relevant differences.

Both Talons and Jaguars are linear. If you calibrated a certain output with one, you should be able to swap to the other with no changes. Victor 888 are not quite as linear, and Victor 884 are not very linear. A value calibrated for a 884 or an 888 might need to change if you switched to another motor controller. See http://www.chiefdelphi.com/media/papers/2720

Both Victors and Talons use a hobby PWM range (1ms to 2ms). The Jaguar uses a larger range to gain more resolution. If you use a Jaguar, but program it with the Talon or Victor class, you will not get to full speed. Alternately, if you use a Talon or a Victor, but program it with the Jaguar class, you will only get partial range. There are less changes between the Talon and Victor classes, but you should always use the class that corresponds to the motor controller you are using. It should only be one line of code or one VI to switch.

Re: Drive with tallons
 

We used talons for OCCRA and they worked without issue. We did put a fan on the drive motor talons for extra protection (although we didn't need them at all)

Re: Drive with tallons
 

A little off topic, but how many MOSFETS are in parallel? #MOSFETS/4. Also, what are the rating for each MOSFET, not the Talon? I'm just wondering how much overload can the transistors take without breaking! If anyone has the info, it would be nice, and I could look at the datasheet if I had the model numbers.

Re: Drive with tallons
 

I expect the Victor888 will have the same issue as the Jaguar or Talon with window motors. Stick with the obsolete 884 or search CD for info on how to remove the lock pin. If you don't need variable speed, a spike could work and would not have the lock pin issue.

The purpose of the lock pin is to hold the car window up when no power is applied. The faster pulses of the modern speed controller does not give the pin time to engage/disengage. Of course, you could use this feature to hold up an arm or some other object that works against gravity.

Re: Drive with tallons
 

Also, has pricing for motor controllers changed while we are in the offseason still? i.e. will these motor controller prices remain this way all season? I swear I remember at least jags and victors being around $40-50 and now Jags are $80 and Victors are $70? and I thought even talons were around 50, but now they are $60... This just seems odd, and I don't remember these numbers before. Can anyone verify them?

Re: Drive with tallons
 

I don't blame these companies for changing their prices to stay with the demand. They need to earn money and support the workers. I agree that the prices keep changing and it isn't anything new. I haven't been paying close attention to the prices, but I believe the prices will drop upon build season because the demand will increase. That means that the supply will increase too!
If the demand goes up, the supply goes up to cope with the demand. When the supply goes up, the price should go down, because the company is operating much more efficiently! Please let me know if my economics are wrong because my knowledge is rusty abter not being used for two years ;)

Re: Drive with tallons
 

Last year, Victor 888's were $50 and Talons were $60. However, last year's prices were surprisingly low. Victor 884's used to cost $90. Jaguar prices varied, but I think the lowest price ever was $70-75 with a team discount and regular price was around $100.

We'll have to wait until the season to see if Vex offers special pricing during that period. Maybe they'll match the price of Talons...

Re: Drive with tallons
 

I've heard this a bunch on CD, but I have yet to see it actually happen. We ran 3 window motors on jags last year on our practice bot, and 2 this year on victor 888's with no problem. We didn't remove the locking pins.