K40 different point from left to right than right to left

Hello everyone, I am new to the forum, I have been looking for forums and this is the one with the most activity of which I found very interesting things.

The topic of this thread is that I have a problem with my k40, making some black vertical lines in raster mode.
The first line makes it perfect but as it approaches the center this line widens until it reaches 2 lines very close together, then these lines come together again until to the right of everything it does well again.
These lines are 0.3mm and it is made of wood. I have been looking at the movement and the engraving point and when it goes to the right it does it at a point and when it returns to the left it does it anotrher point.
I have tried to change the software and nothing. I suspect it is a hardware issue.

Something similar happened to you?

Greetings to all





I upload Photo

Sounds like your frame is out of alignment. When you measure for your focus, I would bet you would get different measurements across your bed moving from left to right. And if it’s focused on the left, out of focus in the middle and focused on the right you might have a bent X axis rail.

Thanks for the reply.
I had already thought that this was the problem, but no, the x-axis is well aligned. I also checked the mirrors and everything in order.
Attached is a photo where the line begins to widen is when the laser makes a long path, which passes the middle of the work table.

Does it do the same thing if you move the engraving to another spot further down the bed?

I.e. does it always start in focus and then change no matter where you are on the bed?

How have you checked the focus across the bed?

I would design a simpler pattern [vertical bars] across the bed and try that to see if if gives a clue.



Are these images useful? long lines are vector engraving. As you can see, it does not matter where the line is placed, if the laser has a long path it starts well, opens the line and then closes well again. There is an image that the lines are shifted to the right and it does exactly the same. I have bought a new main board and I hope it is that and not the motors … which may be another possible failure

I can’t tell anything is going wrong with the long lines but with the short lines in the bottom picture I can see that there’s a double lines being burned.

I would triple check the mirror alignment to make sure the beam is not hitting some edge of a mirror or the air assist cone. Unlikely it is in the controller or motors.

And you REALLY should answer each of Don’s questions…

I notice a ringing on the top and bottom of every other vertical line.

Don’t know if this is clue or not?

Is this when the carriage changes direction?

Have you checked for slop in your belts?
Loose motor pulleys?
Loose mirrors or their mounts?

That noise is when it starts from below or above, it makes that movement, I suspect that it may be from the strong start and it makes me vibrate the support of the X-axis mirror, before I did not answer you how I measured the height, I have a piece that measures 50.8mm , I place it in the corners and in the middle to verify that the piece is well seated.

The straps are fine, the mirrors are secure.

The problem of that noise is not something that worries me right now since the cuts make them perfect. I think that reinforcing the mirror support can be solved, although it would be nice if the software could do a “soft” boot.

In the photo that I attach the engravings are individual except those in the box, these engravings are of a single design.

You can see that when the machine travels a long distance is when it fails, the letters in the boxes are fine, I understand why the laser does not travel much.

Dougl, the mirrors are verified, everything is fine, I don’t have to do with the air system either.