gcode for unload filament at corner before printing starts

gcode for unload filament at corner before printing starts after heat up. is it possible?

I don't understand why you would want to unload the filament before printing, but if that's what you want, this should work in the start G code:

G1 X5 Y5 ; Move to corner
M140 S{print_bed_temperature} ; Set bed temp
T1 ; Select extruder 1 (or 0 depending how your printer is set up)
M104 S{print_temperature} ; Set extruder temp
M116; Wait for temperatures
M83; Set the extruder to relative mode
G1 E-550 F1200 ; Retract all the filament

Dave

Ops sorry, i what i meant is extrude some at the corner before start with printing. To get ready the extruder to print and get some extras ooze off the head.

Quote
antlvk
Ops sorry, i what i meant is extrude some at the corner before start with printing. To get ready the extruder to print and get some extras ooze off the head.

Isn't that what the skirt is for?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

As David says, the main purpose of the skirt is to get the plastic flowing. You can set 1 loop but also a minimum extrusion length, which will result in more loops being printed if the skirt is particularly small (small part). If you want to wipe off the ooze at the start, just park the head just off the edge of the bed while it is heating, and then lower to 0.25mm or so as the last instruction in the start code (G1 Z0.5). This will result in the nozzle being just off the bed height before the print starts, and the initial move to print the skirt should result in the dribble being wiped off by the edge of the bed. Some slicing applications lower the hear to first-layer height before the first move which makes that step unnecessary, while other slicers move first and lower the nozzle after the first move is complete.

Dave

I do the same as the original OP, because I find if I don't do it before the skirt starts printing, the skirt sometimes has blobs which hooks onto my head/print and ruins it.

My macro to achieve the above is:

G1 X5 Y5 ; Move to corner
G1 Z5 ; Lift the nozzle to enable easy cleaning
T1 ; Select extruder 1
M109 S185 ; set temperature to 185, so we can extrude
G1 E5 ;Extrude 5mm of filament