Full Spectrum MLE-40

I’ve dusted off my “ancient” Full Spectrum MLE-40 that I haven’t used in a while.

I’ve upgraded to a new Cohesion 3D controller and purchased LightBurn

I would like to use a Linux PC (Ubuntu 20.04) but although the os address the USB when plugged in the LightBurn software doesn’t find the controller.

A Windows 10 PC registers the USB and LightBurn find the controller.

Question #1: suggestions on getting Linux to find the laser?

Question #2: when trying to be successful under Windows the gets error when trying to “home”. The laser moves to the back middle and just shudders.




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Did you follow all the steps of the installation instructions?
Installing Lightburn - LightBurn Software Documentation

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The machines configured to home and it’s failing the basic ‘boot’ or homing…

Something isn’t configured properly…

Did this work since the controller change?

:smile_cat:

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Um, No…

I only found out yesterday that there was a separate support forum for LightBurn… sigh.

Wow, it’s been a long time (20 years?) since I’ve had to set up a ‘modem’ or ‘terminal’ (probably my Unix days (pre Linux)… That did make the software communicate with the controller. Thanks I’ve got a lot more to read out there now. Thanks again. Now for the next “fun”

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It appears to be trying to home. I have it set to left-rear as home.

I found a set of instructions on the Cohesion 3D site specific to the MLE-40 and changed wiring and connectors as described in the article https://cohesion3d.com/knowledgebase/full-spectrum-mle-40-4th-gen-cohesion3d-laserboard-install/

The console output:
Waiting for connection…
Waiting for connection…
Smoothie
ok
ok
ok
ok
ok
ok
ok
ok
ok
Homing
ALARM: Homing fail
ok
Starting stream
Layer C00
error:Alarm lock
On or near line 0:
error:Alarm lock
On or near line 0:
error:Alarm lock
On or near line 0:
Job halted
Stream completed in 0:00
ok
error:Alarm lock
error:Alarm lock
error:Alarm lock
error:Alarm lock
error:Alarm lock
error:Alarm lock
error:Alarm lock
error:Alarm lock
error:Alarm lock
error:Alarm lock
error:Alarm lock
error:Alarm lock

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Move the head to the front right (or in the area) and power it up. Do both axes go towards the home corner? This will tell you if both axes are configured to go the right direction on power up/reboot.

Ensure your machines configuration of the work spaces is correct. This is probably in the controller.

Lots of people use those boards here, so I’m sure there is a way to connect Lightburn. Check the above and let us know…

I won’t be able to answer you, have some errands for a big chunk of the day.

Good luck

:smile_cat:

I moved it too the front center and, on home, it seems to “meander” to the back and then just moves side to side slightly.

In the article I referenced earlier I looked at the pictures a little closer (I had the original two board set) and set my wiring for the x and y axis like this:

In looking at the pictures for the original single board I see the following that makes me think that the rewiring might not be correct. I can’t seem to find a board/connector layout document on the cohesion site. alternate pictures from the make me think wiring problem. Do X and Y wires in connectors follow same layout? if so which is corect? R-B-Y-W or W-Y-B-R?


Then I’m looking on another page https://cohesion3d.com/shop/controllers/cohesion3d-laserboard/ and see the following:
YYYScreenshot_2022-04-27_11-33-54

So I’m not sure how to determine the correct color/wiring order… sigh

I don’t know if you want to rely solely on wire color unless there’s a guide made for your specific laser and stepper motors.

Here’s a pinout diagram I found for the Laserboard:

Note the Stepper pin order. They’re consistent for every port. That means that the steppers wired in reverse order are probably done that way in an attempt to reverse direction or possibly because they’re equivalent.

If you take homing out of the equation are you able to control stepper movement? Are they going in the expected direction and under control?

I expect not. If it’s just an issue of direction then you can invert in config.

If control is unpredictable then could be a wiring issue. Can you identify the stepper pinout so that it can be correlated to the board?

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Well… I’m not sure how to identify the stepper pin order. I switched my wires to match the photos on the C3D web site.

Taking homing out of the equation by turning off ‘auto home on start.’ I moved the head to the front/center. In LightBurn I’ve selected the ‘Move’ tab and see the up/down/left/right arrows. On the Y-axis I am able to see that when I click on the ‘up’ (move to the back) and ‘down’ (move to the front) arrow it does work as expected. On the X-axis when I click on the ‘left’ (move to the left) and ‘right’ (move to the right) I see that it moves correctly and then will suddenly move the other direction and go back and forth when clicking the same button.

When I ‘Home’ it goes to the back right (changing the origin doesn’t seem to matter) and then just chatters trying, apparently, to keep going right.

Thanks for the diagram. Now if I just knew how to figure out the stepper wiring without tearing it all apart…

Try to determine if it’s a problem with the stepper, a problem with the cable, or a problem with the controller.

Swap the cables on the motor side. If you try to control X, Y should move and vice versa. Does the problem move to the Y or does it stay on X? If the problem moves then the issue is not the stepper.

Swap the cable back on the motor side. Then swap the cable on the controller side. Does the problem now show on X or Y? If Y works then issue is not in cable.

I finally had some time to look at this some more.

I changed the wiring back to the original setup.

When I switch the connectors on the x/y the servos move in different direction however their behavior is the same as before. When they move in the direction the Y axis move seems to mimic the grid jump that LightBurn shows but every so often it just seems to mot move much and just vibrates. The X axis starts moving in the correct direction but will soon just move back and forth instead of continuing.

I’m assuming that the servos have maybe been setting around too long.

Recommendations on acceptable replacements?

Other suggestions?

Thanks.

Unless the stepper motors (or are they servo-motors?) have been in a high humidity environment like a greenhouse for a handful of years they are likely not the culprit. Slack off the drive belts and move them by hand. If a bearing has failed you may be able to feel the resistance. Check the belts for debris and damage as well.

Are you willing to swap the control cables around and test the cables by deduction as well? The small JST crimps can break as they cycle.

One thought I had comes from the speed of the motion you may be applying.

In Lightburn, under Machine Settings you may be able to reduce the speed. Excessive speeds can lose steps digitally and cause stepper motors to reverse.

Be very careful with the units of time, speed and acceleration. Jumbling those units represents a solid chunk of the troubleshooting seen here.

yes, I guess that they are stepper motors… (I’m an old software guy)

I’ve changed the acceleration in the config file from 2500 to 1000 and now my Y-axis appears to be moving as expected. The Y-axis stepper motor is labeled in chinese with the number 42-2100C08S.

The X axis stepper is still just going from side to side in small increments. The stepper is different with a label of 42-2100B03. The wires coming out are the same colors.

In my “search” it appears that the four wires coming out work in pairs. Can I use a meter to do a continuity test to identify pairs? If that works does it matter the ‘A’ and ‘B’ side wires are connected?

I guess I’ll make up a wire ‘jig’ so that I can more easily swap wires for the testing…

Thanks for your help.

Nema sizes explained:

The 4 wire (two-winding) motors are something you could disconnect and test with a meter.

I fought the wiring on my MLE40- in the pictures the “Y-axis” motor is correct- wire the X to match it.
I still haven’t gotten the lazer to fire off of my cohesion board though…

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