X axis has a tendency to creep

I have a similar issue where my X axis has a tendency to creep such that if I go over my grayscale image again it is misaligned. I am using the stock Nema 17s driven off of the Cohesion 3D board. This means I can’t replace the stepper driver as described in the above solution. BTW, I have similar issues with the TM6600 drivers on my CNC router. They are not reliable for sure. Any help appreciated.

I forgot to mention that I have a K40 laser.

Hi Gary,

I moved your post to a new topic so we can keep address your specific questions here. I’ll wait for your machine pics on your other post and we will start from there. Thanks!

FYI… after reading a bit on the web I decided to reduce the acceleration from the default of 2500 to 500 and the drift went away. I am now in the process of increasing this value until I see it drifting again. I checked the stepper and it was not heating up even when at 2500 so that does not seem to be an issue. I might need to increase voltage to stepper per another suggestion.

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Hi Gary,

You’re on the right track here. Did you get it sorted?

No, it is still creeping… sometime to the right, sometimes to the left.

Hi Gary,

Did you try increasing your alpha and beta currents in the config file? 1.0 is generally a good starting place (up to 1.2 max), just make sure the motors are not getting hot. More information: Changing Stepper Motor Currents

Try also lowering the default_seek_rate (ex: 12000), testing with incremental increases or decreases until fine tuned.

How fast are you trying to engrave on the layer settings? Are you hearing any whining or grinding noises while the steppers are engaged? A picture or video of the results would help with diagnosing the issue.

My alpha was set at .4 and beta at .6. This seems weird, but the steppers are quiet. I set them both to .6 and now the stepper is making a loud whining noise.

Hi Gary,

In the config file we set the default max speed, acceleration, and motor current optimistically, so they may need some adjusting.

Decrease max speed / acceleration and see if it makes a difference:

acceleration                                 1500             # Acceleration in mm/second/second.

x_axis_max_speed                             12000            # mm/min
y_axis_max_speed                             12000            # mm/min
z_axis_max_speed                             12000            # mm/min

alpha_acceleration                           1500             # mm/sec²
beta_acceleration                            1500             # mm/sec²

I seem to have things under control with:

Cartesian axis speed limits

x_axis_max_speed 2400 #24000 # mm/min
y_axis_max_speed 2400 #24000 # mm/min

alpha_max_rate 2400 #24000.0 # mm/min
alpha_acceleration 2500 # mm/sec²

beta_max_rate 2400 #24000.0 # mm/min
beta_acceleration 2500 # mm/sec²

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