[happytriger2000]

Hi,
I purchased a SH40 Laser online from Shen Hui Laser on the 9th of Jan, started using it last Monday. The laser fires ok @ x=0, Y=0 but if the laser goes further right, let say X=60 as starting point, no laser mark was shown.
I did an example by drawing a rectangular shape Length = 200mm (X direction), Width = 80mm (Y direction) to show how the laser mark fades away as it goes further right and I would like to know what actually is causing this? is it out of focus?

Video link:
video3 - YouTube

[buddydog]

Your mirrors are not aligned. Don't run it like that. Align the mirrors. Laser 101. Here is a pretty good video at about 10 minutes in:
https://www.youtube.com/watch?v=KhhOHUe_b6o

Alsoget air assist befor cutting things that smoke and clean mirrors and lens.

[happytriger2000]

Thanks Buddydog!

[buddydog]

Your welcome. Please post back when it's fixed to help others that find this thread. That guy does a pretty good job and It's how aligned mine. He stops unfortunately at the head 45* down mirror. To check it's alignment (after aligning the other mirrors) with the lens I removed the lens and placed a piece of tape over the bottom hole and shimmed (since there is no adjustment on that last mirror) with paper on the edge of the mirror to get it into the center of the hole. A better lens head is on my list of mods.

[happytriger2000]

Hi Buddydog,
The video link was very helpful, followed the instructions on lens alignment @ 9:36 ~ 15:00, stick the double sided tape on to Lens 3 ( lens 1 nearest to Laser tube, lens 2 on Y axis, lens 3 on X axis), move the laser head to the furthest right bottom, fire laser and result was not hitting the centre spot, slightly off.
Looking from the Top view, picture below the green dashed line is what we want the beam to be, before alignment the beam was hitting somewhere off the center which is shown in Red dashed line, to improve the alignment I adjust the lens 2 anti-clockwise by how much I do not know you would have to test for each turn of the screw, do not turn it too much.

adjust lens 2,


My 1st laser engrave:

[buddydog]

Yes how much to turn the screw is trial and error and it will change slightly when you tighten the lock nut. The lock nut just needs to be snug, not tight. Did it fix it? Test adjust, re-test. Very tedious but the better you do it the better the results.