Calibrating the knife

Do these in order, with a scrap sheet of vinyl on the mat.

1. Offset X/Y

1. Tape a sheet of paper on the mat. G28, CUTTER_MODE.

2. Cut a small cross centred on X100 Y100:

   G1 X95 Y100 F3000
   CUT_PLUNGE
   G1 X105 F600
   CUT_RETRACT
   G1 X100 Y95
   CUT_PLUNGE
   G1 Y105
   CUT_RETRACT
   

3. PRINTER_MODE, then G1 X100 Y100 Z1 F3000. The cold nozzle now hangs over the point the macros think the knife was.

4. Measure from the nozzle centre to the cross centre. Correct offset_x / offset_y: if the cross is to the right of the nozzle, decrease offset_x by the distance; if it is to the left, increase it. Same for Y (cross toward the back: decrease offset_y). Restart and repeat until the error is under 0.2 mm.

2. Cut depth

Cut a 20 mm square with --max-feed 600:

CUTTER_MODE
G1 X50 Y50 F3000
CUT_PLUNGE
G1 X70 F600
G1 Y70
G1 X50
G1 Y50
CUT_RETRACT
PRINTER_MODE

Result	Change
Vinyl not cut through	Lower z_cut by 0.05
Backing paper cut	Raise z_cut by 0.05, or reduce blade exposure
Corners not closed	Lower cutter_scv, or add blade offset compensation in Inkcut
Corners torn	Lower cutter_accel and --max-feed

3. Speed

Raise --max-feed in steps of 300 until corners start to round, then step back. 1500 mm/min is a safe default for Oracal 651.