[thomasmayo]

Hi there, bit of a newbie to the laser cutter forums so please excuse my lack of knowledge. Anyway here goes...

I've had my Chinese machine for about 3 months now and have been really impressed with it, came fully working right out of the box and have had no issues, until now.
The problem is probably best illustrated through the photos, but basically the engraving is behaving pretty erratically, with power from the laser being fired irregularly - for instance if I was to engrave a square into a piece of wood and then cut it half on a saw, the engraving profile would be different to, let's say if I engrave another square but this time it has a circle in the middle. The engraving tends to start off really weak in both circumstances, and improve if the laser has to 'jump' in order to clear some artwork in the middle of the square.

It used to be completely fine, and engrave all the space around the artwork within the square at the same depth. I really don't get what's going on and I'm desperate to get it fixed as work is piling up!

The laser has had some pretty heavy usage, sometimes engraving 8 hours with intervals per day, but I'm sure it hasn't reached it's 2500hr max usage. However, it also won't cut through a piece of 3mm hardboard anymore, even on a max power / low speed setting.

The pics attached show two planks cut with the same file stored on the laser cutter (top one cut when I got the laser, bottom one cut yesterday) Note the 'sloping' towards to the top of the letter which improves as soon as the laser has to jump to clear the letterform.

Anyway thanks for reading and I really appreciate any help or feedback on this.

Tom

[thomasmayo]

I should add that all mirrors are aligned, I've also checked if problem still exists using unilateralism instead of sweep (both X + Y axis) and also sweeping on Y axis causes same issue... :tired:

[buddydog]

Well here is a stab at it: High voltage leak. Some dust has accumulated some where and has a carbon track across it. That maybe able to be cleaned up. Fire it in a dark room while observing the tube, HV wiring and also the power supply.If it's not that I betting you have a failing tube or power supply.

[thomasmayo]

Thanks! I'll give that a go. It seems to be working better on a lower power, giving a more consistent engraving on power 80 instead of 100...

[Bigbird48]

it would help to list your machine and wattage. but if you have a 40 watt ebay laser your not gonna get 2500 hrs on a tube maybe 1000 if your real lucky. I've had tubes go bad in 200 hours.

[LaserMikey]

Does it get progressively worse as it is used? Could be a cooling issue depending on your climate (do you have a chiller to regulate the temperature?)

I wonder if with heavy use, the mirrors and lenses might have buildup on them? Cleaning with some isoprol (100% alc) regularly usually helps remove grime and dust which may be why you cant cut through the 3mm wood anymore. I notice after cleaning, the cut is better and requires less power.

[Hippo70]

You shouldn't be running it on 100% . Ive been told to run mine at 65% until I get an ammeter fitted so I can see I'm not running it past the tubes top ampage.

Cheers Rob

[SignWave]

I also have a similar issue. Tube is a 90W SPT. It has very low hours on it. The tube lases and excites but it puts out very little power. This tube has a red dot diode laser built in. It is aligned also and the mirrors are clean. I suspect a power supply issue but I am not yet sure..

the beam also looks like sausage links.... What does your beam look like?
from 40% power input and up the output diminishes. if that make sense. At 60% I cannot cut a piece of paper. At 40% it will zip through as it should and then some.