Drinking your caffeine this late? Date must have gone well:) Yes, the steps per mm setting in Marlin is based on the gear that’s driving the chuck which is an XL 25T pulley which has a 5.08mm pitch and results in a 25.2 steps/mm config in Marlin. That’s a one-time setting. The gcode ripper software will take a gcode file as input, which can be a laser file or a cutting file, and wraps the gcode about an axis based on the entered stock diameter. I take no credit for gcode ripper, it belongs to Scorch at Scorchworks web site. I noticed the software was crashing with most of the test files I was using so I debugged and added options to wrap about ‘E’ axis for the MPCNC crowd.
The 3-jaw chuck on the tailstock is definitely overkill for laser engraving but I’m going to try the router on this thing next and I want extra holding power for that test. I’m not a big fan of the chucks after initial testing because they require too much Z axis clearance height to allow the jaws to open. I think I’m going to re-design using a scaled up collet system, like an ER-11 type deal with different sized collets for different sized stocks. My main accomplishment for now is proof of concept for Marlin and Gcode ripper. If you can think of a good design for the rotary then please be my guest. I’m definitely an amateur where that’s concerned. I’m going to make a few changes to mine and do some router testing before I prepare a write-up and BOM and turn this thing loose.