Improved PrusaMk3 Start GCode

M862.3 P "[printer_model]" ; printer model check
M862.1 P[nozzle_diameter] ; nozzle diameter check
M83  ; extruder relative mode
G90 ; use absolute coordinates

M104 S155 ; set extruder temp
M140 S[first_layer_bed_temperature] ; set bed temp - do these first so they can heat while it homes

G28 W ; home all axes without mesh bed leveling
G1 X10 Y-3 Z150; move extruder above bed in front for easier cleaning

M109 S155 ; wait for extruder temp to reach cleaning/retraction temp
G92 E0 ; reset extrusion distance
G1 E-1.0000 F1800; Retract 1mm to prevent oozing.
M300 ; beep to let us know to clean
G4 P15000 ; Wait for 15s (15000ms) for cleaning, will likely have more time waiting for the bed

M190 S[first_layer_bed_temperature] ; wait for bed temp
G80 ; run mesh bed leveling routine
M109 S[first_layer_temperature] ; set and wait for actual extruder temp

; Audiorazor's longer purge line
;go outside print area
G1 Y-3.0 F1000.0
G1 Z0.4 F1000.0
; purge line
G1 X55.0 F2000.0
G1 Z0.3 F1000.0
G92 E0.0
G1 X240.0 E25.0 F2200.0
G1 Y-2.0 F1000.0
G1 X55.0 E25 F1400.0
G1 Z0.20 F1000.0
G1 X5.0 E4.0 F1000.0
M221 S{if layer_height<0.075}100{else}95{endif}

; Don't change E values below. Excessive value can damage the printer.
{if print_settings_id=~/.*(DETAIL @MK3|QUALITY @MK3).*/}M907 E430 ; set extruder motor current{endif}
{if print_settings_id=~/.*(SPEED @MK3|DRAFT @MK3).*/}M907 E538 ; set extruder motor current{endif}