Can Victor and Jaguar motors work together on a single gearbox?

[AdamWiwc]

We have three Victor motor controllers and two Jaguar motor controlers, can we put those together on a single gearbox so that we have two motors on each side of the robot totaling of four motors? Is it a better idea to use one of each type on either side or two Jaguars on one side and two Victors on the other?

Thanks for your time.
Team 5185
The dial up grizzlys

[apalrd]

It's not really recommended to do anything but all the same controllers for the drive motors.

If I was in your case, I would put a Victor and a Jaguar on each side. While this could lead to unequal loading of the two CIMs at any part load point, IMHO it's better than the robot drifting to one side because of controller difference.

[Jon Stratis]

The Victors, Jaguars, and Talons all have different response curves - meaning if you told them all to go the same speed in the code, the actual results would be a little different. Thus, it's not recommended that you use different speed controllers with the same gear box. Also, for good control of your robot I would make sure all the speed controllers on the drive train are the same!

[Domtech]

Generally no, the pwm rates for Victors and Jaguars are different, so they would not work off a splitter. Additionally they provide different powers at the same joystick position unless you do a bunch of fancy programming to equalize the 2.(I have not heard of anyone attempting this)

It is recommended to always use the same controllers for multi-motor gearboxes.

[Ether]

Originally Posted by Domtech

Generally no, the pwm rates for Victors and Jaguars are different, so they would not work off a splitter.

Yes they would. Both Vics and Jags will operate properly with PWM period ranging from 5m to 20ms.

Additionally they provide different powers at the same joystick position unless you do a bunch of fancy programming

True for the Vic884, not so much for the Vic888. Even so, all it means is that one motor is carrying more load than the other.

[Seth Mallory]

You have a lot of teams in Calgary and you can possibly trade with one of them. It could be quicker and if you are on a budget you can save the purchase price. Teams in our area have loaned and traded parts for years when needed.

[Mr. Lim]

Originally Posted by AdamWiwc

We have three Victor motor controllers and two Jaguar motor controlers, can we put those together on a single gearbox so that we have two motors on each side of the robot totaling of four motors? Is it a better idea to use one of each type on either side or two Jaguars on one side and two Victors on the other?

Thanks for your time.
Team 5185
The dial up grizzlys

We mixed jaguars and victors on our 6 motor drivetrain last year. 2 Victor 888s and 1 jaguar per side.

While it works, we noticed the jaguar motors working much harder than the Victor ones, and had to write some code to rebalance everything. The jaguar motors were heating up while the Victor motors weren't.

[DonRotolo]

Precisely.

The answer to the OP is "yes". But: Some motors will work harder than others, because the curves for the controllers are different.

[Ether]

Originally Posted by Mr. Lim

we noticed the jaguar motors working much harder than the Victor ones ... The jaguar motors were heating up while the Victor motors weren't.

OK CD community: What's the underlying physical explanation for why this happens?

@Mr Lim: Just to eliminate one possibility: Are you certain the brake/coast settings were identical on all controllers?

[Richard Wallace]

Originally Posted by Ether

OK CD community: What's the underlying physical explanation for why this happens?

When a Jag and a Vic are shown the same PWM signal, which develops more voltage at its motor terminals?

[Ether]

Originally Posted by Richard Wallace

When a Jag and a Vic are shown the same PWM signal, which develops more voltage at its motor terminals?

RMS or arithmetic average ?

[Richard Wallace]

Originally Posted by Ether

RMS or arithmetic average ?

Let's go with arithmetic average for now.

[Mr. Lim]

Originally Posted by Ether

OK CD community: What's the underlying physical explanation for why this happens?

@Mr Lim: Just to eliminate one possibility: Are you certain the brake/coast settings were identical on all controllers?

I'd like to hear an explanation for this one. Although I'd have to check the PWM / Voltage curves more carefully, my guess is because the Jags have a more linear response, in general for any given PWM signal they would produce a higher (magnitude) voltage than a Victor, except for at the extremes, where they would be the same (Vbatt).

Yes, I am certain both would have been on coast.

Our drivetrain runs open loop most of the time, and we do check that all speed controllers on it are specifically set to coast.

[Mr. Lim]

Originally Posted by Ether

RMS or arithmetic average ?

RMS, assuming we drive both forwards and backwards... or turn!

[Ether]

Originally Posted by Mr. Lim

Yes, I am certain both would have been on coast.

Are you also certain that:

all the controllers were properly calibrated

and

your code was using the appropriate input pulse width range for the Jags and the 888s?