I have a 2w opt laser and a Tim Rothman board…my laser is delaying 3s after the code begins to run… like it will run for 3s not firing and then will start to fire and finish the project… what am I doing wrong?
So for the first 3s are you saying that the laser head starts moving about the job normally but does not fire?
If you go into LightBurn’s Move window and use the “Fire” button with 10% Power what happens? Still a delay? How long? Click fire a second time or use Stop to turn it off. (If you don’t have a fire button go to Edit > Device Settings > and switch on “Enable laser fire button”).
Yes.
3s in for both running a project and pressing the fire button
What happens if you unplug the (3 or 4 wire?) connector to the laser module, click on the fire button, wait for at least 5 seconds, and then (with fire still active) reattach the connector.
Does it now fire straight away, or wait another 3 secs before turning on?
Its running right now, I’ll give it a shot though. With Tim Rothman’s help, we put a little lead gcode in and it starts where and when it should currently
If you run a layer with 100% power, measure the pwm output and see if the delay is there…
This identifies the laser module as the issue if the pwm goes active immediately…
You might need to ask Tim Rothman about it… 
Just out of curiosity… do you have a $32 and is it set to 1?
Is your laser something like this…
I can see, by the design of Tim’s board, that there is no delay in the pwm signal. Lightburn is not putting an M5 instruction in the code.
My laser is wired TTL, +, gnd, gnd
What gcode did you add to get this to work?
I added the following:
M4
G04P10
That’s very odd.
M4 would enable variable power for the laser.
Then G4P10 would basically wait for 10 seconds.
I wonder if your laser module is somehow taking time to activate. I hadn’t heard that of Opt lasers in the past.
If the control board is supplying a proper pwm, without a delay, then it must be the laser module … ? 
I think perhaps the ground wire is not connected properly/has slightly too much resistance causing a reduction/delay with the current required to initially prime the laser module.
One way to test this would be to to use the fire button in the move window e.g;
Click on the fire button (at 10%)
Stop firing by clicking the fire button again.
Click fire button back on again.
Look to see if it fires instantly the second time (as opposed to using the Stop button and then firing which powers the laser module down and up again and will probably still have the delay).
Quite possibly could be…there are 2 grounds so I ran them to the main ground…I just tied together…so there may be a slight difference in the ground signal due to that