Cant cut through

hi i have had a k40 about six months after setting p the mirrors it worked amazingly well all was standard.

but recently it wont cut through all over the a4 2mm mdf.

so i installed a 5mm steel base to give me a good base and installed a jacking device but even with careful mirror setting and focusing i am still getting poor results, does the power supply or tube loose power ?, i even purchased a new coldray laser head that was supposed to fit, laugh i made a new bracket and managed to fit it but its no better than the one that comes with the machine.

so what do i do uy a 50w tube and power supply or a new 40w tube

any ideas


Tubes and LPS are actually consumable.
The tubes loose power and the LPS High Voltage Transformer shorts out.

There are many causes of low power at the imaging surface other than tube or LPS, usually alignment.

What are your symptoms:

What current is your tube drawing?
Are there any noises like snapping or cracking from the laser tube or LPS?
What coolant are you running?
Did this problem start after you installed the new cloudray head?
Have you done a ramp test to insure you are at the right FL?
Have you checked that the beam is exiting the objective lense in the center and is perpendicular to the surface?


Also, when doing the alignment, do you get a single round spot or do you get multiple spots or one that is distorted in shape?

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to answer all your questions in order
it will draw 30ma if i let it .
there is no cracking or snapping just the normal sound when the laser is firing
i am using just water and its tepid to mildly warm in use
i had the problem before installing the new head (but that has not helped at all
i have done a ramp test with not very good results, and i have moved the table up and down to try and improve the cut
and the laser fires in the middle of the mirror.

have replaced the mirrors with si mirrors and fitted new focul lenses

i am sure the mirror alignment is correct

thats why i am asking for suggestions
i am at the end of my teather



What was not so good about the ramp test?

Usually, when we see users with these symptoms the problem is in the objective lens.

Certainly, you could have a bad tube or LPS but it doesn’t sound like it since the machine is not that old and you did not over-temp it? Unfortunately for these parts, it’s a diagnosis of exclusion. i.e. we have to prove everything else is working.

Haven’t seen an answer to this?

Post pictures of what a burn looks like at each mirror and also a video of the tube when firing.

i cant see what you are looking for

but here are the pictures of the tube



at the first mirror i get a elongated spot, because its at 45 deg

the 2nd and third good round dots



hi here is the pictures of the burns they are out of line because i have been messing trying to improve it but they were lined up



ps sorry for delay it kept bouncing it back saying files to large

What does the burn look like at the table set to the right focus?


hi believe its a good burn, but over a a4 sheet of mdf it cuts intermittently, and if i run the same ct again on a different sheet it gives bad cuts in different place, baffles me