Laser turns off after following code is sent after M3

dc42

@craigb244 said in Laser turns off after following code is sent after M3:

;
; Operation: 2
; Type: Laser Cut
; Paths: 1
; Passes: 2
; Cut rate: 5 mm/s
;

; Pass 0

; Pass 0 Path 0
G0 X57.57 Y76.11
; Pass Z Height 5mm (Offset: 0mm)
G0 Z5.00

M3
G1 X7.57 Y76.11 S255.00 F300
G1 X7.57 Y9.42
G1 X57.57 Y9.42
G1 X57.57 Y76.11
G1 X57.57 Y76.11
M5

; Pass 1

; Pass 1 Path 0
G0 X57.57 Y76.11
; Pass Z Height 4.8mm (Offset: 0mm)
G0 Z4.80

M3
G1 X7.57 Y76.11 S255.00 F300
G1 X7.57 Y9.42
G1 X57.57 Y9.42
G1 X57.57 Y76.11
G1 X57.57 Y76.11
M5 ; Disable Laser/Spindle
M106 P2 S0 ;turn off laser power

I just tested that file on 2.05RC2. It runs OK except that it turns the laser off at the start of the 4th side of the 2nd square. I will look into it.

dc42

On further investigation:

You are using both M3/M5 and G1 S parameters, which I wasn't expecting;
If I delete the M3/M5 commands so that it uses just G1 S oarameters, it works correctly
If I delete the G1 S parameters so that it uses just the M3/M5 commands, it fails

So G1 S parameters appear to be wrking correctly. but M3/M5 commands are not.

dc42

I found the issue with M3/M5 in laser mode. I am postponing the 2.05RC2 release until I have fixed it.

craigb244

@dc42 thanks for looking into this and glad my info helped find the issue (even more glad it's not something I've done my end!)

By the way my firmware is 2.04RC4 (2019-10-19b1)

Quick question...
You say "You are using both M3/M5 and G1 S parameters, which I wasn't expecting;"

Is using M3/M5 not the "correct" way to control the laser?

dc42

@craigb244 said in Laser turns off after following code is sent after M3:

You say "You are using both M3/M5 and G1 S parameters, which I wasn't expecting;"
Is using M3/M5 not the "correct" way to control the laser?

I was expecting user to either use M3/M5 to control the laser, or (preferably) use the G1 S parameter.

To fix this, what I plan to do is to make M3 set the default laser power for the start of the next G1 move, but not turn the laser on immediately. Likewise, M5 would set the default laser power to zero for the start of the next G1 move, but not turn the laser off immediately if it is moving. In both cases, an S parameter on that G1 move would override the power set by M3/M5.

Does this sound reasonable? It means that the laser will never be on when the machine is not moving. In one way, this is safe because it avoids accidentally burning a hold in the bed. However, it means you could leave the machine in a state in which the laser has been "primed" by M3, so that it turns on (perhaps unexpectedly) when you next do a G1 move.

dc42

I have now made this change and released firmware 2.05RC2. Please note, your original file included M3 commands with no S parameter. This is not correct, because the M3 command requires the S parameter to specify the required laser power. However, as your code includes S parameters on G1 commands, the M3 commands are not needed.

I note from https://reprap.org/wiki/G-code#M3:Spindle_On.2C_Clockwise.28CNC_specific.29 that Repetier firmware also does not fire the laser except during G1/G2/G3 commands.

craigb244

Thanks,
The code is what came directly out of laserweb 4, I might message them and see how I can change the way the gcode is produced,

I'll update my firmware tonight and let you know how it goes.

Thanks again.

Craig

morokolli

Hi,
Updated to 3.0RC1, similar errors.
In my earlier example (peukku.nc) error have moved to another location (bottom line).
And while lasering star last line fails.
Gcode used for star:

;Project taehti
; *** START begin ***
G90
G21
M84 S0
G92 X0 Y0 Z0
;No. 1: Engraving 1
M3
G00 X15.2204 Y25.2874 F1200
G01 X10.3421 Y17.0845 F1200 S255
G01 X1.3756 Y19.1117 S255
G01 X7.3967 Y12.1317 S255
G01 X2.4490 Y3.8119 S255
G01 X11.2939 Y7.6139 S255
G01 X17.5111 Y0.4065 S255
G01 X16.6361 Y9.9102 S255
G01 X25.4043 Y13.6792 S255
G01 X16.0954 Y15.7838 S255
G01 X15.2204 Y25.2874 S255 ; this line fails to laser. 
M5
G00 X0.0000 Y0.0000
M05

dc42

Did you try 2.05 ?

morokolli

No, update fails:

T3P3Tony

@morokolli see this thread about downgrading: https://forum.duet3d.com/topic/13401/cant-change-from-v3-0-to-v2-05-missing-file/9

morokolli

@dc42 I'll rather stay at V3 codebase.
Reverting back to 2.05 requires re-setting too many things (endstops, laser control, etc..)