TTL control - The laser is always on

Hi there, help me please!

I am using a TTL laser from Bangood. See the link below.
I connected the laser TTL module to the Control board of 3018 CNC Router and power it with 12V from an external source. The laser is always on. It did not work, so I just create a sketch in Arduino and connect a multimeter to see the voltage and it could be 0-5V but the laser is ON all the time.

How can I turn it off and on from the controller?

Thanks in advance!

Laser:

Control board of 3018 CNC Router:

There are specific changes needed for laser use under GRBL.

First off you would need to upgrade to GRBL 1.1 which has better laser support.

Then the laser will normally use SPN EN (spindle enable) pin and ground and it can be PWM'd via the spindle speed so for example G0 S0 would be laser OFF and G0 S255 would be full power.
That last number can vary depending on the max spindle speed set in GRBL so if you normally have a spindle capable of lets say 1,000 then 1,000 and set to that in GRBL then 1,000 would be full power and anything between that and zero would be incrementaly lower 500 being 50%

is it a 3W or a 5W laser as they will be different in usage.
5W would be considered absoloute minimum for decent usage.
Anything below that is probably Ok as a plaything.

Also do not forget the focus range of a laser is also relative to its height above the workpiece for the most part.
There are some very complex calculations to the actual method but in home use you tend to be in the 10-50 mm range. Part also depends on the power of the laser and its focal length.
Here I run 15 mm with a 15W laser and around 20-25 mm depending on material with a 10W laser.

You also need a crossflow of air across the surface.
That does three things.
First it helps stop fogging of the lens due to smoke and debris.
Second the extra oxygen passing across the surface aids the lasers cutting action.
Thirdly you need to get rid of the fumes to an external source or via a filter.

On my laser machines I have old computer fans with a good CFM doing a push/pull acrosss from each other.
I actually have two in push and one in pull with cheap chinese speed controllers to allow me to vary my flows and have found them also useful when doing regular machining as they blow the finer dust out of the exhaust system.