I have a fully functional setup with my FoxAlien LE4040. Its GRBL and I’m using windows 10. Im using the latest version of Lightburn as of nov 4th. Its accurate and dialed in. I created a rotary tool and am in the process of dialing that in. I have unplugged both the y axis motors from my main setup and plugged in the rotary. I changed the origin point from bottom left to top left and turned off my homing/ hard limit switches. I am using absolute position and am using the lightburn rotary setup with 10mm rollers and currently my rotations per mm is 39. When I burn a rectangle I get the 100mm x 10mm as expected, but when I jog from the top right position of the rectangle (that sits on the 0 x axis) to the top left position using the “Set laser position” tool, (upsidown teardrop in the left menu icon) It goes about 80mm. In my GRBL settings my y axis still has the same value for the y stepper 101=80, but Im not sure the motor is exactly the same as the others. (1.8 step angle means 200 steps per rotation but I dont know where the 80 number came from math wise, it was just the recommended settings that came with the laser cutter).
So when I burn, or I frame, the laser travels the correct distance, but when I jog it only goes 80% of the way there. Help!
If 80 steps/mm works perfectly when the machine is not in rotary mode, this $101 value needs to stay set at 80 steps/mm. LightBurn will scale the output when in Rotary mode when you use "Start’ or save the GCode.
For example, in the Rotary Setup, you told LightBurn that to turn a roller with a circumference of 31.41mm a full turn, the axis needs to be commanded to move 39mm.
So now, when rotary is enabled LightBurn will scale output to the Y-axis by 124%
As far as I know for GRBL, manual movement using the Move window or ‘Position Laser’ jogging controls are not subject to rotary scaling - so in your case if a 100mm jog move was sent unscaled to the rotary axis the actual travelled distance at the rotary will only be 80mm.
If you wanted everything to be scaled so you could use those jogging controls, then theoretically I guess you could disable rotary and ignore Rotary Setup, and instead manually adjust the $101 Y-axis travel resolution to reflect the 124% scale change yourself, (e.g. type into the console ‘$101= 99.3’) and remember to change it back to 80 steps/mm when you are done.