Intermittent Error on the Jrk 21V3

I’ve been using the Jrk 21v3 for some time with no issues to pitch a small camera. The set-up uses a potentiometer for feedback. I decided to upgrade the camera but now I am getting Motor Driver Error periodically. It is not latched and goes away but then returns. What can cause this error? Plotting the current does not indicate that it has an over current issue but I haven’t measured it directly. In addition, the motor can barely move like it is struggling and it use to pitch rapidly. I even remove the camera so there was essentially no load on the motor but still these conditions exist. I did reset the Jrk 21v3 to its original parameters but have not been able to isolate the cause of Motor Driver Error. Thanks for any help you can suggest.

Here is some follow up. I checked the voltage to the controller and it is fine but just in case I charged the battery. With the motor shaft directly connected to the feedback potentiometer via a flexible shaft coupler, the speed is still slow. I’m sure the Max Duty cycle and Max Acceleration are set to 600 (Max) (default settings). I did not have the computer connected for this test so I’m not sure if the Motor Driver Error is still fluctuating. Could a bad connection to the motor be a culprit?

The motor driver error occurs when the driver’s fault conditions are triggered (under-voltage, over-temperature, or over-current for the jrk 21v3). The error also occurs when the jrk is connected to USB and motor power becomes disconnected. Is your camera powered from the same source as the jrk? Since it sounds like the problem started when you switched to the upgraded camera, I suspect the camera could be pulling large spikes of current, causing the voltage to drop and trigger the error. Could you try removing the camera from the setup (electrically and mechanically) and seeing if the problems persist?

A bad connection to the motor might be causing the unexpected motor behavior. You might try disconnecting the motor form the jrk and applying voltage directly to the motor terminal to make sure the motor still works as expected. You could also use the plot in the Jrk Configuration Utility to look at the duty cycle to see what the jrk is outputting to the motor.

If you try those suggestions and continue to have problems, can you post pictures of your setup that show all of your connections? A video of the problem might be helpful as well.


The power for the camera is independent so that is not a factor. Yes the problem did persist after removing the camera from the set up (I wanted to reduce the ‘load’ on the system). I do know that with the change in the set up of the system I have/had other issues that I’m trying to correct. i.e. the potentiometer was not exactly lined up with the motor shaft causing extra load on the motor.

With no load on the motor the test I did at lunch did seem like the controller was functioning correctly going to the correct position based on the input but it just very slow compared to its regular speed.

I did a temporary solder joint on the leads for the motor so its possible that is not a good connection. I’ll do more testing tonight and if I can’t get it to work better I’ll take photo’s or video to show you what is going on. Thanks for he help.


The problem seems to be from the power source. I’m using a SLA battery to power a regulator that feeds the motor controller. When I used a different battery directly into the motor controller without the regulator, it works like a champ, without the Motor Driver Error. So either the regulator or battery is going bad. Thanks for the support.


I am glad you were able to find the source of the problem. Thanks for letting us know.