Extraneous retraction command at beginning of print file

[boatanchors]

On my QIDI Tech 1 and X-pro printers, the startup scripts finish by extruding a line of filament along the front edge and then wiping the ooze from the nozzle before the actual model-related gcode begins to execute. For some reason, S3D is inserting a retraction command as the first model-related gcode instruction, causing the first several centimeters of the model to be "skipped." I have removed the "Force retraction between layers" setting from the setup and this makes no difference. The amount of this first retraction and its speed are the same as is specified in the process settings for the model being printed.

This is the affected area of the gcode file:

****************Startup script begins here
G90
M83
M73 P0 ; Enable build progress
G162 X Y F3000 ; Home XY maximum
G161 Z F1200 ; Home Z minimum
G92 Z-5 ; Set Z to -5
G1 Z0 ; Move Z to 0
G161 Z F100 ; Home Z slowly
M132 X Y Z A B ; Recall home offsets
M135 T0 ; Load right extruder offsets
G1 X-110 Y-70 Z30 F9000 ; Move to wait position off table
G130 X20 Y20 Z20 A20 B20 ; Lower stepper Vrefs while heating
M127 ; Set fan speed
M140 S50 T0 ; Heat buildplate
M134 T0 ; Stabilize bed temperature
M104 S205 T0 ; Heat right extruder
M133 T0 ; Stabilize right extruder temperature
G130 X127 Y127 Z40 A127 B127 ; Default stepper Vrefs
G92 A0 B0 ; Zero extruders
G1 X100 Y-70 F9000 ; Move to front right corner of bed
G1 Z0.3 F6000 ; Move down to purge
G1 X-90 Y-70 E24 F2000 ; Extrude a line of filament across the front edge of the bed
G1 X-100 Y-70 F180 ; Wait for ooze
G1 X-110 Y-70 F5000 ; Fast wipe
G1 Z0.5 F100 ; Lift
M73 P1 ; @body (notify GPX body has started)
****************Startup script ends here
G1 E-1.6000 F3600 <---this is the first line of the S3D-generated gcode

Is there a way to remove this G1 command? Is is included in the QIDI printer profiles for a particular reason?

TIA for help!

[rrdavis]

If you have retraction enabled, it will retract before moving to the print (that's what it's supposed to do, retract before making a move over open space).

So you would need to disable retraction all together if you don't want that to occur. You could use the variable settings wizard to disable it for the first layer only if you needed to.

[boatanchors]

Thanks for the quick reply, rrdavis. Of course, your explanation makes complete sense...hadn't thought about the open space issue; too bad that, in this case, it defeats the effect of the initial purge/prime. Since many users have their startup scripts perform the prime/wipe sequence to prepare the extruder for the print, it might be useful for S3D to include an "Omit initial retraction" checkbox to allow users to control this particular case. Then, the user could control exactly what happens to best suit their needs. In the meantime, I'll give your suggestion a try...I appreciate the suggestion.