[kobo96]

my 50 watt laser machine China now presents this anomaly,
double line ?
Pulse laser not correct ?

testing alignment lenses ok
lens clean

thank you

[cinematic2]

Alignment is ......
Did you check third mirror?

[cncbasher]

this is down to alignment , or you have a reflection of the main beam and picking up the secondary
you need to check alignment at both ends of travel and at centre in all 3 plains and make sure the beam is central down the z axis tube
easy way , turn the power way down low , and ink to end of the nozzle with a felt pen or ink pad push a peice of card or thick paper on the end and fire one short pulse
take the paper off and you should see the bullseye by the ink and the ( hopfully ) small hole in the centre , if it's off centre then adjust the lens , so the beam is central

if paper is burning too much use a peice of 1/8" plastic

[gfacer2]

I've had this. I think it was more than one issue.

I had this and I think the biggest issue was a scratch or flaw in the mirror (it was a while ago and of course you are trying everything at once). The other test is to do a low power tape fire before the first mirror and see if the beam coming out is weird at all. Mine was too (last tube), I had some main spots and then a off centre lighter spot.

I still have the issue slightly but changing out 2 of the 3 mirrors and (for other reasons) the tube seemed to get it down to a minor level.

It can also be hitting the cone as mentioned, so you can try a shot with the cone off to test that theory.

[kobo96]

thanks for your answer,
problem solved ok !!!

[KeithOKC]

Did it end up being alignment of the third mirror or what ended up being the issue? Curious to hear the solution you came to?