Controlling position of linear actuator with jrk 12v12


The question is regarding the pololu configuration utility for jrk12v12.
I’m trying to control a servo city linear actuator: ( … tuato.html) with the pololu jrk 12v12 motor controller with feedback. I want to be able to control the position of the actuator using the slide bar. The connections between the jrk and the actuator are as follows:

Blue wire(reference) -> FB
Yellow wire -> AUX
White wire -> GND
RED wire -> A
Black wire -> B

The Dilemma:
When feedback is disabled, the jrk functions in speed control mode (as it should) and the actuator works fine. However, when feedback is enabled (analog feedback mode), and the slide bar moved, for some reason the max current error (12 A default) is exceeded and the actuator jerks abruptly making a sound. If the slide bar is moved again, nothing happens. After the max current error is cleared, the actuator jerks again when the slide bar is moved in any direction, and it is found that the max current error was again exceeded.

Next, I disable the max current error and try to move the slide bar again. This time the actuator shudders violently making a weird shrieking sound before abruptly coming to a halt. I’m thinking I’ve killed it so I try to test it with a potentiometer but it seems to work just fine. Nevertheless, I enable and latch the max current again because I’m scared! I repeat the whole thing and get the same reaction from the actuator.

Next, I connect an ammeter in the circuit to see if the max current of 12 A is actually being exceeded. It shows a current of 0.02 A when the configuration utility indicates that max current is exceeded. But maybe 12A is exceeded momentarily and then actuator stopped suddenly so the ammeter cannot update fast enough to show 12A being exceeded?
I just want to be able to move the actuator to any position using the slide bar in the configuration utility. What do you think am I missing? I can send you more details. It seems to be simple issue and I would really appreciate the help to fix this.



Hello, Salman.

Welcome to the forum! Could you tell me more about your setup? What are you using to supply power? What are your PID settings set to? Under the Motors tab, what do you have the Max. current set to? Could you post the jrk settings file and a photo of your entire setup, including all the connections?

- Jeremy