Laser powers down between StartPause/CutThrough and actual cut

LightBurn Software Questions
1

I’m using a Creality engraver which I’ve modified as a Pen Plotter. In order to allow time for the pen to go down, I’ve added a StartPause delay with Cut Through enabled.
The problem I’m facing is that as soon as the delay starts, the “laser” is fired so the pen goes down. But when the StartPause delay ends, the laser goes off and then immediately goes on to start the cut. I need to avoid that laser power going to zero:
This is the generated G-Code. you can see a G1 S0 that turns the laser off/pen up.

; LightBurn Core 2.0.05
; GRBL device profile, user origin
; Bounds: X100.91 Y339.61 to X110.08 Y350.89
G00 G17 G40 G21 G54
G90
G0 X48 Y273
G91
M4
; Cut @ 4000 mm/min, 10% power
M8
G0 X4.692Y-7.446         ; Rapid move to start position (pen up)
M3                       ; Laser ON (constant power mode)
G1 F100 S100             ; Feed slow, power 100% — this is the "start delay" 
G4 P1                    ; Dwell 1 second (pen stays down)
G1 S0                    ; Power to 0 (pen up signal! - HOW TO AVOID THIS?)
G0                       ; Rapid mode (pen up)
M4                       ; Laser ON (dynamic power mode)
; Layer C06
G1 X0.011Y0.313S100F4000 ; Start drawing (pen down, power 100%)
G1 X0.043Y0.297
G1 X0.075Y0.282
G1 X0.108Y0.267
G1 X0.14Y0.251
2

Perhaps disabling the Emit S Value With Every G1 Command will help.

Some folks with plotters / plasma cutters / gadgets end up post-processing the G-Code file with a text editor to remove / modify specific commands. This would be straightforward with a stream editor like sed in Linux, which is apparently available for Windows.

If that’s not feasible, then a deep dive into a Custom G-Code device may be in your future. :grin:

1 Like
3

Thank you Ed. But that option is already disabled.

4

Well, it was worth a try. :grin:

1 Like
5

Did you try entering
G1 F100 S100(0?)
G4 P1
per layer in Custom GCode? Or just before the instruction in the Cut Move box?

image
image691×621 12.9 KB

Can you post here your device. lbdev for us to check?

6

Thank you parsec.
I was able to create custom G-Code for ToolOn/Off and that works.

Tool On

M3
G1 S200 F6000
G4 P0.01

Tool Off

M5
G0
G4 P0.01
1 Like
7

I also created a request but probably won’t have much traction :slight_smile:

8

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