Y-Axis engine stutters when accelerating

Hi there,

I just finished assembling my farmbot, I’m now trying to calibrate movements and endpoints.

My Y-axis motor acts funny, it stutters (see video) during acceleration phase. Then, after the first few seconds of acceleration, it works regularly.


But this leads to “failed movement”.

To remove any possible friction I just isolated the engine from the belt as you can see on the video.

Any help is very appreciated. Please consider I’m very new to farmbot.


Would you grab a screen shot of your configuration (encoders and motors) and post? I’m pretty new as well, but knee-deep in encoder hell (self inflicted) - may see something…


One thing I noticed is that your gear is right down on the shaft and looks like it is touching the mounting plate. Try moving it away from the mounting plate a little. Also make sure the grub screws are on the flats of the motor spindle.


Thanks Cris for your reply, I did not enable encoders and I did not touch default values, so I’m not sure… however, here there is the screenshot of my configurator…


Thanks again

Hi Mark, thanks for your time…

That is not a problem, I had the gear removed and it does the same, I had put it just the gear back to make it more visible in the video, but again, the engine stutters even without really touching anything.

Thanks again

Try to increase/decrease the acceleration length in the parameters. If the behaviour still persists, try to swap the stepper driver with another axis. If the issue moves with the stepper driver, check the driver current (by measuring Vref) as it is described in this post (search for " Adjust the stepper driver output power").

You can also try running the motor with the encoder unplugged. That will tell you if there’s a problem with the encoder that’s causing the behaviour.

As @Ascend mentioned, check your settings for acceleration distance, max speed and torque. If you have a multimeter, you could also monitor the voltage output from stepper motor driver. If it drops then it could be a driver problem or a power supply issue. Check the power supply by measuring between the fuse and the USB port on the farmduino. It should be a steady 24V.

Listen closely to both the motor and the electronics box. Any clicks or abnormal noises may also help diagnose the problem.

Hope you find your issue soon!