Focus diode laser at reduced power

Is there a way to reduce power while focusing the laser? There is no red dot on my laser. Need a way to turn on the laser at a safe level.

You have not provided anything about your setup (controller / type of laser) but, for gcode based systems - go to ‘Device settings’ and enable the “Laser fire button” switch, then restart LightBurn. There will now be a button to fire the laser at low power in the Move window.

I don’t know if your controller has the ability but what I do is adjust the ON time of the laser pulse instead of power.

I am also curious because my lightburn does not have that. I use a ruida controller that you can control that through the control board: power maxpower 1/2, minpower 1/2.

Why would you fire the laser while focusing it? The eye is not very good at determining the smallest spot size. There is a safer way to set the focus distance. Do a ramp test and make a focus gauge.

What are you trying to do? What am I missing here?

This completely depends on the type of laser. A lot of diodes don’t have a movable head or bed, but have an adjustable focus lens, so for them, this is normal. For CO2 lasers, the focus is usually fixed, and leaving the beam on while you try to manually focus would be really dangerous, so a ramp test is the way to go.

You’re right, of course. I didn’t think of diode lasers.

Just read the post from Rick James. That is exactly what I needed. Thank you so much. By the way, I have a 3 watt Chinese laser. $200 total. It’s as fast as holding a magnifying glass under the sun, but it works. I’ll upgrade later.

Right, for determining correct focus distance you would do the ramp test. But for aligning the mirrors a single short pulse is very useful.

Finally, I like to do a test where I lower the bed as far as possible and fire a pulse onto a piece of thermal paper, then raise the bed and fire again without moving anything else. This will tell you if the laser is firing perfectly perpendicular to the bed, and it will also give you an idea of the beam profile and if there is any clipping.

Read the thread for context - the user doesn’t have mirrors, or a movable bed - he’s using a $200 diode system.

My apologies, I did not realize that only diode laser users would be reading my post.

I wasn’t denigrating your choice of laser. I genuinely did not understand what you were doing. As soon as Oz pointed out my blind spot, I understood why you wanted to control the power while focussing the beam.

No apology necessary. I wasn’t clear about my equipment and what I needed. As a hobby, I make jewelry boxes with my CNC router and now I can use my laser to add people’s names to the inside.