Sharing my purge and wipe script
Hey guys,
I spent this past weekend trying to nail a perfect first layer, I'll preface this by saying I don't own a prusa, I have a frankenstein printer and I slice with prusaslicer so there was no elegant startup script for my "custom" machine. A big problem I was having was a retraction blob that would get dragged through my first layer and ruin every print before it started. It turns out the REAL problem was too much backpressure in my bowden system (which was finally corrected by using a negative value on de-retraction length) anyways during this journey I wrote what I think is (for me) the perfect purge and wipe script:
(note: when it gets to the "cut the worm" line it quickly drags the nozzle over a little tab in my drip-box, and that last little z-lift after the wipe does a great job of leaving any remnants from the cut on the end of the wipe before the skirt starts printing)
; Init position G28 ; home all axes G0 Z5 F500 ; Lower Bed for clearance ; Heat up M117 Heating... M140 S[first_layer_bed_temperature] ; set bed temp M104 S[first_layer_temperature] ; set extruder temp M116 ; Wait until target temperatures for extruder and heated bed are reached ; PURGE G1 F200 E10 ;extrude 10mm filament G92 E0 ;retract G1 y100 F5000 ;cut the worm! : WIPE FORWARD G1 X-3 F500 ;move to edge of bed G0 Z0.2 F500 ; Raise bed to .2 (first layer height) G1 y188 E10 F500 ; extrude 10mm filament over 88mm y-axis G92 E0 ; retract ; WIPE BACK G1 X-1 Y128 E9 F500 ; start purge line G1 y88 E12.5 F500 ; finish purge line G0 Z2 F500 ;z-lift anti-drag