Help ! Upgrade chinese 40w laser to 50W

[Mcbride19]

I would look at dirty or poor quality optics. Or something is blocking part of the beam. Which is usually the nozzle below the lens. The beam looks mostly in focus but very low power. You can see that in the wide cut where the beam mostly bounces off. How does it do on thin soft wood? It should blow thru 3mm wood.


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There is a lot of things that can affect the power of the laser beam, here is some:
The path of the laser is not perfect.
The mirrors are dirty.
The lens is dirty.
The distance between the lens and the wood(or leather or else) is not good.
The alignment of the path.

I don't know how to find what is the value of the optics, but here is why it's important, the optics concentrate the beam at a certain distance. It means that with an optics of 28,1 you will have a thiner beam with extreme power but that will cut less deeper, with a 50 it will give a lareger beam with less power but that will cut deeper. You must understand that laser does not cut wood by burning it but by impact it. So the deal is to concentrate the power of the beam to have the most perfect beam possible with the better power you can( it depend of the power of the laser tube). For exeample with a 50 w you will have a 28 or 32 optics, and for a 100w you will have a 40 or 50 optics( it will help to cut deeper ).

[Mcbride19]

here is some explanations :

Frequently Asked Questions about CO2 laser lenses for cutting

[alexm1]

I discovered that two of the mirrors looks good after cleaning, but the one from the cutting head it is pretty much gone...I think.

I will try to make some mirrors from a old HDD (metalic mirror inside) before seller will send a new mirror.
Thank you for your tips.

[Mcbride19]

you're welcome !

[alexm1]

After I ve put on hold this hobby...now I am back to try again to make more adjusments;
Now I discovered that moving laser head along Y axis burned dot is going up (see pic).
If I move laser head along X axis laser is burnind in the same spot.
I can not find any explication for this behavior.

And another problem is that: both pulley wheels (end of the belts) from Y axis are not perfectlly round, actually are pretty oval shape and when I move laser head along Y axis I get strange noise, probablly from the belt being too tense.

Could those faulty pulley wheels be the problem for moving dot(laser burn) when head is moving along Y axis?

Photo atached and video in the link



Sorry for my english..not a native speaker.

[Mcbride19]

After I ve put on hold this hobby...now I am back to try again to make more adjusments;
Now I discovered that moving laser head along Y axis burned dot is going up (see pic).
If I move laser head along X axis laser is burnind in the same spot.
I can not find any explication for this behavior.

And another problem is that: both pulley wheels (end of the belts) from Y axis are not perfectlly round, actually are pretty oval shape and when I move laser head along Y axis I get strange noise, probablly from the belt being too tense.

Could those faulty pulley wheels be the problem for moving dot(laser burn) when head is moving along Y axis?

Photo atached and video in the link



Sorry for my english..not a native speaker.

I may be wrong but it seems that you must correct the path of your laser beam, it's just a question of compromise beetween the two distances.

[KH0UJ]

Nope your pulleys are perfectly fine, your problem is the mirror calibration process, the more you go farther on the table it gets offset, in your case usually the first mirror need to go a little bit to the right or hence calibrate it again (near, mid, far) that time you took out the mirror you messed up the calibration

[alexm1]

I will add more pics with pulley wheels after disassembly, to see how it looks like the holder.
Moving head along X axis, laser beam hits in the same spot(no matter if it is closer or far from the second mirror), but with laser head moved along Y axis(my first pic) laser beam goes up from rigth to left.

And the sound it the same in this video but on the Y axis:

[KH0UJ]

on my opinion even if you take out the belt and pulleys just the sliders itself, if it`s perfectly aligned beam on the mirrors it wont go offset even if you just move it by hand with no pulleys and the corrugated belt

[alexm1]

Yes, I think you are rigth....
if I have more time to investigate, I will take it out (again) both axis and I will give it a try without belts on Y axis.
In fact, moving the head in the centre, using as perimeter 200/200mm laser beam is prety weel aligned.

About lens, does it matter mounting possition ? It came with lens mounted in A possition. Could work in B possition too?(see pic).

[alexm1]

After I managed to align mirrors ... I was playing for a about 15 minutes wile with my k40 ...and 2 days ago, laser tube does not give any beam. Does not stopp working durring a job, just on the next Power On laser tube give no answer when I hit test switch button.
Could be a faulty power source?
The fan is blowing, the laser head is moving, but GREEN LED on the PSU is not ON and when I push the small button (TEXT) next to LED-nothing happens.

I know for sure when it worked well Green LED was allways ON.
Soo,,PSU or laser Tube is dead?