Laser Alignment Issues PLease HELP

Ok thanks for looking at this. This issue has been driving me crazy.
I have a Chinese laser cutter. Model is DH130-80
It has two lasers.
A 120 watt and a 80 watt.
I have had issues with trying to align either one. So right now I am only focusing on aligning the 80 watt.
So I went through all the alignment steps a bunch of times already (Bearded Builds has some very good videos)
So in the photo
M1 is Mirror one
M2 is mirror two
and M3 is mirror three

The red dots on the mirrors shows where the laser hits when head is at that location

If I do an alignment along the Near side (right side) I can hit laser 3 dead on everytime.
If I check it close corner (right back) to far corner (left front) it is also dead on
If I check it along front from right to left it is also dead on

The issue is on the back from right to left the laser hits higher and higher and then as I move it towards the front it hits lower and lower till it gets to the front and is dead on.

Everything is bang on level. What on earth can I still be missing? Please help

If I’m reading this correctly… m3 at it’s maximum left side is correct, but as it moves to the rear the mirror is moving down as it travels.

This is the only thing I can read out of this assuming you do have it square elsewhere?

I appears much like the bad corner issue which can sometimes be corrected with an very, very, very small M1 adjustment.


It does seam like a 4th corner issue and I watched a totorial on how it can be fixed with minor adjustments of mirror 1 but this doesn’t fix my issue…
If I adjust mirror 1 then everything else goes out of wack.
Has anyone shimmed the track a bit?

Maybe you could check with a laser level if you need to.

I will make a video of all 4 corners and post it

But shimming wouldnt actually fix anything…
Will try again monday

That’s why I stated very, very, very small adjustment.

Thought I’d suggest it anyway…

Good luck


What is the result at M3 in these two positions highlighted?

Are they lower than they should be? like in the zone 1,30 of this diagram?:

M3 is dead on all along right side… And also dead on all along front side
Sent from my iPhone

I would go back to M1 and and start again.

Remember when aligning mirrors try not to focus on getting the spot at dead centre of the next mirror - it is far more important that the burn spot does not change position when the next mirror moves from as close as it can be, to as far away as it can go.

If it turned out that the position of the burn spot was too high on M2 after you had aligned M1, then you would have to either lower the tube slightly, or raise M2 and M3 mirrors slightly - it depends how the beam lands at M3 after aligning M2 and how much adjustment you have available at M3.

After you have the M1 beam perfectly parallel with Y, then do the same with X, and take the first spot close to the right side rather than in the middle (middle is not necessary and lessens the accuracy) .

My guess is that your M1 needs to be tilted up very slightly, and your M2 tilted downwards very slightly.

Bellow is a link to a video I took of the alignment issue I have… Let me know what you think

Alignment video

Saw the video, thanks.

Alignments can be tricky!

What does m1(y-axis) alignment look like?

Because the bed is wide, it will be very important that m1 is perfect, before moving on to m2.

On those large machines I like to level them first to help ensure the chassis isn’t twisted. I use a good spirit level and place it on the y rails, and place on x gantry in the middle (check at back and front). You should have adjustment at the feet.

Thanks for replying…
So M1 I am calling that the mirror right at the laser tube…
M1 to M2 (mirror on the y axis) Is perfect

Machine is perfectly level

Yes that’s what I call m1, and it has to send the beam down the y axis, so I think of m1 as alignment for y.

I know i’m sounding like a stuck record now, but is the spot near and far for M1 down the y axis perfect?

Its easier to see the exact center of the beam using a small square of clear acrylic instead of paper.

I suggest you try tilting m1 upwards a smidgeon while checking the spot at m3 in the front far left corner.