X axis problems - smooth on left, rough on right

(Sandi Laveault) #1

Machine: _ Chinese 60 watt CO2. It came with an M2 Nano board.

Board: Cohesion 3D Laserboard

Firmware: GRBL

Problem/ Question: First, a little background, I am new to lasers. I have only been working with this one for a couple months. I never did use it with the original M2Nano. I was having problems, and was recommended the cohesion 3d laser board from someone in a FB group that got me set up with the board and with Lightburn. So when my laser was running and the head movement was sounding a little rough, I thought that was normal, I had nothing to compare it to. It was getting the job done, and doing a nice job, I wasn’t that concerned. But then it started jamming…

My laser head is “jamming” along the x-axis, but only if it’s working along the middle to right hand side of the work area. If I have a small job that is only using about 4" to 5" of the left hand side of the work area, it runs so smooth. Here is what I have done/discovered so far:

  1. The laser head travels very smoothly when I home it from the opposite side of the work area or if I use the laser move buttons or use the “google maps” icon to move it around the board. It runs so smooth no matter where.

  2. I tried burning items in 3 spots. Along the left side of the board, it runs very smooth. In the middle, it gets rough and sometimes skips/slides. Along the right hand side is very rough and definitely slips/jams. See my youtube video links below.

  1. I tried changing what it was I was burning. On the right hand side where it is at its worse, I made a simple rectangle covering that area, and it scanned through the simple rectangle without issue. Text on the other hand, will “stick” and “jam” it up.

  2. I have tried different speeds from 200mm/sec to 350mm/sec, and no change from above.

  3. When I manually move the laser head back and forth along the x axis (and the y), it moves very smoothly.

  4. I have tried changing the x axis acceleration to 1800 in the lightburn machine settings, it doesn’t help.

  5. In case someone thinks this matters, I have aligned my mirrors, laser comes out in center, lens is cleaned.

  6. Something I think is unrelated but I’ll put it here in case it’s important, I tried attaching a rotary tool (the cheapest kind that plugs right into the cohesion 3d) and between myself and my fb friend who also uses the same board and software, we couldn’t get it working properly.

  7. Here are the settings my FB friend helped me with when setting up the board for the first time in lightburn:


Thank you so much in advance to anyone for your help, I have jobs here waiting, I’m losing money. :frowning:

(Jamie Richards) #2

Welcome! Can you provide photos of your motors or at least the part numbers?
I’m curious about size and electric current specs. The motor only has to work slightly harder when the head is on the far side, but if it’s not being supplied with enough power, that slight difference may reveal itself.

What operating system are you using? Photos of the board, wiring and screenshots of your LightBurn config may also prove helpful. The more info about your system the better.

Does this match your size settings in LightBurn?

Also, what problems were you having before the C3D install?


(Sandi Laveault) #3

Hi Jamie,

I am using Windows 10 Home. Yes, our x and y matches in the lightburn software. Before the C3D install, I was having problems getting the text in the chinese software to the output of the laser. For example, I just wrote some random text, and the output was a rectangle. It could very possibly have been user error. I’m typically very comfortable with software and learning new, but this was driving me crazy and decided right away to upgrade.

Also, the yellow ground wire coming from the back of the laser, we have tried grounding it to the chassis and grounding it to earth ground through the house wiring… no difference in either one.

I’m going to reply again using my phone to upload the pictures…

Thank you so much!

(Sandi Laveault) #4

New Uses are only allowed one picture per post, so here is one of eight…

(Sandi Laveault) #5

(Sandi Laveault) #6

(Sandi Laveault) #7

(Sandi Laveault) #8

(Sandi Laveault) #9

Correction, I have 6 pictures. This is the last one.


C3D comes pre-configured for the K40 Laser.

You have a larger machine so you would to change some values for motor currents (increase these to 1.2), and decrease the maximum speeds and acceleration substantially. You can use the device settings in LightBurn to do this for GRBL-LPC in an understandable fashion, but usually we recommend people stick with the stock smoothie firmware (which will require loading the files onto the SD Card and keeping the SD card in the board) to tune their machines, and then transition over to GRBL-LPC once they have those values nailed and written down.

Same thing for rotary, start with Smoothieware.

Files for Smoothie are here: LaserBoard Firmware + Config Stock Files on Memory Card

Some of the articles in the FAQ such as this one will explain the process to modify the config file:

The two gentlemen in this thread, Christophe and Ray, have a larger machine with the LaserBoard and have spoken about the changes required in some depth. I would recommend going to their profiles, the activity section, to find the 5 or so threads that pertain to this.

It is worth noting that you should really try to solve one problem at once, otherwise train of thought gets too scattered and providing support becomes difficult.

(system) closed #12

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