I almost finished building my CNC engraving machine using parts from ARCO System kit, stepper motors from 3D printer that broke down, and engraving motor from a too-small CNC engraving machine. I'm using GRBL Panel. I found out that the X and Y distances are off. From the readouts in GRBL Panel, I got 9.993mm instead of 10mm. I tried to watch the video at https://openbuilds.com/projectresources/howto-calibrate-your-cnc-machine-for-mach3-or-grbl.145/ but I'm hearing-impaired and the closed captioning is screwed-up. How can I calibrate the machine?
Here is how I did it. First, I calculated my steps/mm (theoretical) with my lead screws which were supposed to turn 1/2 inch (12.7mm) per revolution using this formula Grbl v1.1 Configuration · gnea/grbl Wiki · GitHub: steps per mm = (steps per revolution x microsteps)/mm per rev. So for me and my 200 step motors with 1/8 microstepping (aka 8) and 12.7mm/rev the formula looks like this: (200 x 8)/12.7 = 125.984 steps/mm. Or, here is a simple calculator for obtaining your starting (theoretical) steps/mm for both belts and screws RepRap Calculator - Prusa Printers. I wrote the formulas and calculations in the video for calibrating actual vs. theoretical. Also, there is no speaking in this video. Just the sound of me tripping once while filming.
