Attached is a photo showing how the height of my lowrider changes during a cut. The x-axis is to the left of the “G”; the y-axis is at the top of the letter.
I use Fusion 360 on a MacBook Pro to design with an add-on to generate the gcode for Marlin-based machines. Repetier Host sends the program to my lowrider Rambo 1.4 (no end stops). Z-steppers are set up in parallel.
In the past, the gcode generated by the Fusion 360 add-on contained a command to move the z-axis at the rate of 2000 mm/min. This would cause the gantry to become crooked because one z stepper would lurch upward before the other could respond. I manually reduce those commands to 200 mm/min plus I change all other z commands so they are less than 300 mm/min.
For the situation I’m presenting, I tried the following troubleshooting ideas:
I measured the distance between table top and the lowrider at various points along the x-axis, but the measurements did not vary.
I used the LCD control to run the spindle along the x-axis and the height never varied from one side to the other.
I ran the z motion up and down several times with the LCD control and the height stayed the same on both ends of the gantry.
I simulated a cut with a design built to run the spindle along the x-axis at slow speed so I could verify there were no height differences occurring anywhere along the path. The x and y movements in the gcode are set to 1800 mm/min; anything less and the end mill will melt portions of the foam (Dewalt 611 at lowest speed)
For the “G” that I picture, the only z-axis commands are at the beginning of the cut (to drop into the cut) and the end (to lift out and return home).
I need help with identifying additional troubleshooting steps I should undertake. I’m confused about the variance in cutting height when there are no z commands in the program during those variances. Could I have a loose wire or some other mechanical/electrical anomaly such as cross-talk? How would I determine such?
Thanks for your advice. For all my past problems the response time has been amazing - usually the same day…not that the pressure is on…