Issue: before running any gcode and just moving X and Y axis, I see some jerking motion that concerns me. I believe that I may need to manage the servo's movement deceleration. After help from OpenBuilds getting a Blackbox controller replaced after I may have damaged it, I'm excited to see my project move for the first time. Thanks! My project is very similar to the one documented at the link below. I'm adding servo control to my wife's Longarm system. The X axis is approx 12ft wide and Y axis is about 3ft deep. The sewing machine and gantry are big and heavy. When testing movement with X+/- and Y+/- there is some major "jerking" happening. I've reviewed all of the Grbl settings and have identified the ones I need to adjust, if at all, including the $120 and $121, as well as $11. But I was thinking I'd see a comparable deceleration settings that insures that when coming to a stop it would slow down instead of stopping suddenly. Is there a way to control this, or will this issue not be a problem when I run gcode for a quilt pattern. I don't know anything about the tools I've asked my wife to explore and learn to use for generating gcode from patterns--the process seams straightforward thanks to Soat Mon in the video. That may be where I have some control over how the servo moves the system. Thanks for your support. "My DIY CNC Longarm Quilting Machine" https://www.youtube.com/watch?v=tQJAv6M2AA0 Nema 23 servos Ubuntu 22.04 BlockBox Motion Control System x32
yes, you need to adjust the acceleration values for all 3 axes. the defaults (you did load a machine profile, right?) are usually quite slow but your machine may be too heavy for even that, so go ahead and set them to half the defaults and test. Tied to the accelerations are calibration and max rates. Start with low max rate and low acceleration and do the calibration (In OpenBuildsCONTROL under Wizards and Tools). Once movement is accurate you can tune for sensible max rate and acceleration.
Ok I will simply proceed with plans to calibrate and adjust settings and see where it ends up. AND, I will assume you read that my issue is "Deceleration" and not acceleration, which is not mentioned in the settings or other guidance. We all know that acceleration is opposite of deceleration right. Good Thanks
Grbl has one setting for both . Applies to both. Same rate up and down. Makes logical sense the mass and enertia aren't really different between start and end of move
