Hi Axia,

As I mentioned earlier the M11/M10 command set stops issues, such as the Dot Burn at the start of your laser line (as shown in your pic.) and without using a motion controller that supports those commands you are severely limited in what you can achieve with your laser.
As Reuelt suggests a micro switch may be a work-around but if you want to produce quality work then junk the cheap Chinese controller and invest in a controller that properly supports all the Mach3 commands.

Tweakie.

Thank for the advices guys! I think I have to live with the situation, keeping the limit switch option as my ultimate solution if no soft solution available.

For the controller, I will try to dig further into the drivers or maybe try to find a NVUM forum. At the same time I am also looking into a serious (offline) controller, for the next machine maybe. If I could be advised of any good model, will be glad to hear.

Also will try Arduino as controller for laser, when have time.

If it’ any help…

This video https://youtu.be/8fUg6ebWut0  is Mach4 but it demonstrates just how an unused Axis Direction Pin can be used to switch the laser ON/OFF and a PWM signal to control laser power for a combined engraving and cutting toolpath.

The attached pic was laser produced on some scrap plywood using the Pokeys 57CNC controller.

The Mach3 motion controller I use on a daily basis is the Warp9 ESS.

Tweakie.

With the Pokeys 57CNC you can also make use of Freeware "Auggie CNC Addon" written by retired MACH3 creator (everyone knows who) for higher Quality Laser engraving/Photo etching.

If you are into laser, perhaps Pokeys 57CNC motion Controller is preferable to Warp9 ESS Motion Controller even though ESS has already proven to support laser.

The only motion Controller that can support Auggie is Pokeys 57CNC.

Thank you guys, I have downloaded the ESS and 57CNC manual and reading them for my preparation to the next machine. Good documentation and datasheet make the product better.

For the async issue I seem to found a workaround.
In the m113 and m115 code I added the below code before turning on/off the output#1:
sleep 1000

This will delay the output and is actually working!!! I have done several tests, only thing is the overburning. As I am not using M3/M5 I don't expect built-in delay. Still need to tune the delay try to minimize the overburn. At least this can be a workaround for controlled spindle.