Y axis issues

I am having the similar problem with the chinese K40 clone, but mine is the Y axis that will not work properly.

Since you seem to have mostly resolved your problem, could you give a quick summary of what actually made corrections. that may help me with the Y axis problems.

Sincerely trying to get this thing fixed …

Can you describe more about the issues you are having? Pictures of the machine and wiring and a couple videos of what is happening with your machine would be extremely helpful.

What controller are you running in the machine? Have you made any changes to the machine?

Yes, Joe, I replaced the board with the new Cohesion 3D board, came today. After resolving issues with communication: getting a good cable and using smoothie, the laser will home and attempt a print.
The X axis is working fine it appears, after the first tenth of a second where I can lose a vertical line as it starts up. The Y axis acts jammed or uncommunicative it moves a little, grinds moves some more. sometimes it doesn’t move at all resulting in a horizontal burnt line.

I can physically move the laser head to all quadrants. With the power off, it moves relatively easy, grinding when I try and move it with power on. It seems as the motor isn’t receiving enough power. This card has no way to adjust that parameter.

ResultofTest ![SquaresTest|432x239]

hopefully these uploaded ok, you can see the problem.

Another picture, I can only do one at a time … LOL


Stepper motor in use by the Mophorn 40 watt laser clone

I did not ever see any issue with the original board, but it never actually worked either, since I needed to run lightburn software.


Fixed that. Feel free to add as many as needed.

I would start by bringing the amperage on the Y axis driver to 1.1-1.2 amps. This is done in the config.txt file on the sdcard.

This could also be an issue with acceleration. Having the acceleration set too high can cause stalling like you are seeing. When I am testing that I usually lower by half at a time to make the tests go a little faster.

Start with raising the amperage for the stepper drivers and repeating your tests.

If you have more issues please post your config so we can check it as well. Let me know how it goes.

That was an easy fix. I wish I had some idea about the difference in the two boards in the installation instructions. Would have saved me hours.

Thanks, it is working great.

Well, that was TOO easy, there is still some problem in the Y axis and I don’t know if I need to reduce the current or tighten the belts somehow. The variation in Y makes it unrepeatable to go over a previous path.

here is an example, perhaps that will tell a more experienced person what I am facing.

Thanks in advance, great progress has been made, now the minutia is killing me.

Can you take a screenshot of your settings? Curious how fast you’re going with this. I think your X acceleration may high as well, looking at the top left corner of the box.

Greetings again, Joe.

Here is a screenshot of the settings and a set of test circles I am trying to print.

Here are three attempts at sending this to the laser:

As you can see, I am not having a good time. At least, thanks to your help and the
YouTube examples, I am actually getting some output now.

Type is a big problem, how will I cut the letters so they are not all outlines?
I need them to look as much as regular type as possible.

anyway some things are working, I just need to get it repeatable.

by the way, I tightened to Y belts so there was only 1/2” of slack when pressed, realignment of the lasers.
adjusted the Y motor amperage to 1.2 amps and did other frustrating things.
It will operate almost correctly as long as you are in one straight line of text.
not being repeatable, makes it not useful.


I’m having trouble understanding what the remaining issues are. Can you take video of the issue you are having and link it here?

Your circle test shows that there is an issue but the issue isn’t clear where it is coming up. When I am testing issues like this I like to use patterns that are clearly defined to show the issue. Maybe a circle inside a square that touches on all edges. With that if the circle doesn’t touch the square somewhere or overlaps it’s clear what axis is having the issue.

I understand it’s can be frustrating to work through these issues but working through them one step at a time is the easiest way for us to help you.

Greetings Joe,

I have been busy learning the software and trying to compensate for the laser problems.

There has been some resolution, I fixed the Y axis bar that was misaligned by more than 20mm end to end.
Then I had to realign the mirrors. Went back and lowered the current to .8amps

still was having problems with repeatable image scans. lowered speed to 35mm/s and it is dead on.

problem now is I don’t know how to set the focal length, or proper focus. I can cut nothing thicker than a business card. So I did some test passes with the workpiece at an angle … the picture shows
the second picture shows my settings.
In 8 passes it only cuts just over 1/8” it just doesn’t seem to get any deeper. Must I have air assist to cut?

thanks for your patience, I could write a book about what I have learned so far, but I have a few things to overcome before it works right.


This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.