yonkiman
Posts: 42
Joined: Fri Sep 04, 2015 5:31 pm

[SOLVED] How can I eliminate retraction at start of print?

Fri Sep 22, 2017 11:42 am

S3D seems to insert a retraction at the very start of a print, immediately after it runs the Starting Script (which unfortunately means I can't put an unretract in my Startup Script to undo it).

Is there any way to disable this?

Example:

Code: Select all

G90
M83
M106 S255
M104 S210 T0
M109 S210 T0
; This is where Starting Script is inserted
G1 E-5.0000 F6000 ; this is the retraction I'd like to eliminate
G1 Z0.200 F18000
; process Process1
; layer 1, Z = 0.200
This was asked last year as well but never got an answer (https://forum.simplify3d.com/viewtopic.php?f=23&t=4334).
Last edited by yonkiman on Sat Sep 23, 2017 3:09 pm, edited 1 time in total.

gearsawe
Posts: 150
Joined: Sun Sep 10, 2017 11:06 pm

Re: How can I eliminate retraction at start of print?

Sat Sep 23, 2017 12:45 am

I thought this was a problem too but there is an unretract before it does start. Look a few lines down your gcode. here is mine. Think this was their way to fix the un-retract at the beginning of each layer. But what really happens is if you note the end of the print there is a retract then the beginning has a retract. I would like to use the keywords [retract_distance] in the start script but this keyword is only supported in the retraction script area. All keywords should be supported everywhere!

;Start
M140 S100
M190 S100 ;wait bed should be set
M104 S270 T0
G28 ; home all axes
;G0 Z2.1 F5000 ; Add offset for when printing on GLASS
;G92 Z0 ; reset z to 0 after offsetset GLASS
G0 Z20 F5000 ; lift nozzle
M109 S270 T0 ;wait
G92 E0
G1 E3.5 F1200; un-retract from amount on last print
G92 E0
G4 S5
G1 X100 Y100 F4500
;Start End
;retract
G1 E-3.5000 F1200
G1 Z2.250 F2400
; process Tower1
; layer 1, Z = 0.250
T0
; tool H0.250 W0.500
; skirt
G1 X38.831 Y36.799 F9000
G1 Z0.250 F2400
G1 E3.5500 F360; un-retreact before prints
G1 X39.106 Y36.685 E0.0149 F288

yonkiman
Posts: 42
Joined: Fri Sep 04, 2015 5:31 pm

Re: How can I eliminate retraction at start of print?

Sat Sep 23, 2017 3:09 pm

Thanks! That's very helpful. I missed it because I'm using hardware retraction, so I'm substituting all my retractions with G10 and G11, using a post-processing script given to me:

Code: Select all

{REPLACE "G1 E-1.0000 F60" "G10; retract"}
{REPLACE "G1 E1.0000 F60" "G11; unretract"}
{REPLACE "G1 E1.0000 F18" ""}
If you look at your code, you'll notice that the unretraction you pointed out (G1 E3.5500 F360) is 30% of your normal retraction speed (G1 E-3.5000 F1200). So my script was deleting the G1 E1.0000 F18 instead of replacing it with G11. If I change my script to {REPLACE "G1 E1.0000 F18" "G11; unretract F18"}, I'll get my unretract back (though it will be full-speed).

Thanks!!!

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