Problem with focus in diode laser

hi all i have a problem with my diode laser, i am new on this world, i buy this laser and received a few weeks ago, one day i make a design, save as gcode, and use, that day the file work great, the second day i use the same gcode, and the design is way diffrent (always darker and less details) so i have to change the power and speed of the laser, and make a new gcode, i work for that day and the next day, use the same last file, it happent again! the desing way burn and with no details, i really don’t know what is happening … , i also have a second questions, i currently have a 40w laser, i know that actually don’t work at 40w becouse i need around 7 pass to cut 3mm plywood, and the border get really burn, so i am looking to upgrape for something around 50-80 wats, somebody currently have any laser module in that range that can cut 3mm plywood in 1-3 pass? thanks so much

As I wrote in the other tread, humidity and focus has a big influence on the engraving result.

It’s possible that you loose power after some time of usage on the day because the diode gets hoter. That would be a warning! If the diode is getting too hot, it will get destroyed.

That’s anyways what I expect from a laserdiode that is advertized with 40W. Such strong diodes doesn’t exist! Which also is the answer to your question: No, there are no stronger laserdiodes.

If you want to cut 3mm playwood in one path you should by a CO2 laser (like the K40).

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thanks so much for your help, i think the same firts, that my laser can get hoter, but i just use a few hours one day, and the design was perfect, i save my machine and use the next day, and do my firts design that day with the same g code , and the result is extremely diffrent, so each day i has to check the laser focus? all diode laser have this problem or is just my laser? i really don’t know… i think that can be a sofware problem, that is why i save the file as a g code and use that file, but each day the result is way different.

and yeah i know i have to buy a co2 laser, the problem is that they are out of my budget right now, i need a lest to have a 20x20 work space, and that is above 2000$, so i am saving some money to in a future buy the muse !

i also order a air pump and a air assist muzzle for the laser, so i will see how that work

To get the most efficient cutting with a UV laser you really need to add an air assist. Using an air pump you direct a stream of air into the laser cut which helps remove some of the charred material while cutting. The char resists cutting.


Good advice. Every word is important here. “If you want to cut in one pass”. I never even attempted to have my new laser cutter/engraver at its highest settings of power and linear speed.

@NedMan I sort of knew that the cutting becomes less efficient with each pass, but I thought it was due to loss of optimum focus. I might try to see if introducing a blower makes a difference.

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See this post for more info. I reference a YouTube video that shows the increased cutting efficiency with an air assist with a UV laser.

(Lol, my phone auto correct keeps converting “UV laser” to U-VERSE. Guess you can tell who my cable provider is :crazy_face:)


With focus you get the best cutting effect by setting the focus point half way into the work piece.


Yes that makes sense… I have to get myself some different thicknesses of veneer. :laughing:

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