Quote:
Originally Posted by MarkoRamius1086
And I agree that using a Jag is a bit overkill (capabilities, space, weight, parts...) for the window motor, a victor or spike should work just fine!
Good luck!
Petrie
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It is not that the Jag is overkill, the Jag combined with the window motor locking pins is a serious problem, one has to go. The motor is stalling because the locking pins do not always release when the motor vibrates at 15kHz (output frequency of the Jag) but do release at 120Hz (output frequency of the Victor).
[EDIT to reply to David]
Quote:
Originally Posted by davidthefat
Oh, great, thank God there are people that agree with me. Another programmer and I have been going at it with each other since day one. I told him "lets use Victors, they are reliable, more robust and teams rarely have problems with them." Keep in mind he is a rookie. His argument is that it is new technology and that using CAN would make us go to championships... Now I explain to him that no one cares how the motors are controlled or programmed, the only thing that would get us to championships is the performance on the field.
I see no real advantage of using CANs... I just need to manually get a closed loop working.
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The real problem is the windows motors were not designed to be run with any speed controller (Victor or Jag), so a spike relay is the best solution if you can do without variable speed control. They were designed to be run with a relay (on/off switch) like on your car window. As a safety feature (to prevent window related injuries to human appendages), they are designed
not to run at stall by using positive temperature coefficient (PTC) resistor (which is what is getting really hot). Reconsider your application of these motors. Window motors are heavy, break easy (plastic output strips out), require an
odd complier to interface to a shaft or a gear, and are the weakest motors in the kit (barring servos). Their only positive is that they are the only motor with a worm drive gearbox, and due to this
Q&A ruling you can't use the window motor gearbox with a better motor (seem to be the only gearbox that is considered integral to the motor). I have had first hand experience with several component using window motors, and basically every one has been unsatisfactory, often to the point where we redesigned with a different motor. I understand some teams have had success applications for them, particularly in steering swerve modules.
There are numerous advantages to Jags and CAN. Jags (PWM or CAN) are the only speed controller you can switch between brake/coast on the fly (we run auto in brake and teleop in coast) and their input to output function is more linear (easier to program control loops IMHO), increased update rate. CAN advantages are multiple control modes (include closed loop for speed and position), increased feedback (including reading encoders without using limited CRIO resources), daisy chain wiring with locking connectors (PWMs tend to come loose without
clips). I use Jags for fine control (i.e PID) of certain components (i.e. drive & arms).
Victors have their advantages, too. They are smaller, lightweight and most veteran teams have a large stock of them. I use them for components that don't require precise control (i.e. rollers, winches).
No speed controller is going to punch your ticket to Championship. They each have different features and you need to find what works for you.