Odd behavior from rotary after job completes

LightBurn Software Questions
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1

I recently installed version 1.7.04 of LB on my Windows machine.
Everything has been working perfectly, but when I installed the roller rotary to engrave a cup it engraves exactly like it should but when the engraving is done the rotary begins turning the cup back and forth about 30 degrees pretty quickly (much faster than the 3mm/sec setting I have the speed set to)

I have done lots of cups on my Ruida CO2 laser so I don’t think it’s user error. The Enable Rotary switch is set, the roller rotary is properly connected to the Y axis connector.

It is just the odd rocking back and forth after the engraving completes that is making me a little nervous.

----------------- EDIT
I just discovered that if I click the “Stop” button on the LB screen the rocking stops.

Has anyone else seen this behavior? Am I making a stupid mistake somewhere?

2

This is very strange. Have you inspected your wiring? Maybe one of the wires is deteriorating.

3

That is a possibility I will check. But it seems odd that it would move perfectly while engraving and then start rocking immediately after the engraving is done if it was a wire issue.

4

What rotary are you using ? I wonder if your stepper driver settings are off, it could be a lack of current. 30 degrees does seem to be a bit more than a simply holding current issue but I would start by checking dip switches anyway. See what the current is set to.

5

I have been using this same rotary for 6 years with no issue, it would be odd if it suddenly needed new stepper driver settings.

6

Yes, that would be a new one for me too. You did not offer us any history or details on the model of rotary or how it is connected etc. At this point we can only guess, unless more details are provided.

It could be possible after years of use your connectors are degraded.

Have you rolled back to the prior version that was working to test if this is software related ?

7

I have a Boss 2016 70 watt CO2 laser with the original roller rotary that Boss was shipping with the laser when I purchased it in 2017.

I will load the prior version and LB (1.7.03) and let you know if it behaves the same.

this video shows the rotary I have

8

I just loaded the older version 1.7.03 and it is behaving exactly the same. I turned the laser off and back on to be sure it was reset and rand the exact same job and it begin rocking back and forth after the job completed the same as with 1.7.04.

So it is not the software, now I am really confused.

I tested the rotary by using the LB motion controls (Up/Down arrow) to move it incrementally and the rotary moves as expected. So It appears the stepper motor in the rotary is functioning correctly.

Also the fact that the Stop button on LB stops the rocking means the rotary must be getting the rocking commands from either the Ruida controller or from LB. I suspect now that it may be the Ruida controller that is misbehaving.

9

You can determine which pretty quick by examining the last lines of the GCode. My bet is on the controller board.

1 Like
10

Remember: Ruida controllers don’t use G-Code, which definitely complexicates the diagnosis. :slightly_frowning_face:

11

Yeah, I keep missing that clue!

Still think it is the controller.

12

Problem solved. It was me being stupid

Before I engrave an expensive bottle I wrap it in aluminum foil and then wrap some masking tape over the foil so I can do a test engrave at low power to be sure I have the text setup correctly and that the bottle behaves nicely on the roller.

After the test engraving is verified I remove the tape and foil and do the “real” engraving at the correct power

So I have two layers defined

Test Layer (Blue) mode = Fill speed = 350 Pwr = 16 LPI = 400
Real Layer (Black) mode = Fill speed = 225 Pwr = 45 LPI = 150

Both layers should have a scan angle of 0, Bi-directional fill, no cross hatch and fill all shapes at once set

But for some reason my old brain had the Test Layer (Blue) set to cross hatch, so when I ran the test engrave it engraved everything just fine and then it started cross hatching and since it was on rotary mode it would start rocking the cup back and forth while very slowly moving the laser head back across the cup (so slowly I did not notice it was even moving)

Sorry to have wasted anyone’s time with my stupid mistake.
Once again the LightBurn software is just doing exactly what I told it to do.

Hopefully this may help someone else in the future if they see the same behavior, and are old like me.

4 Likes
13

NOT a waste of time. We add this to the list of possibilities for what you described. Nobody mentioned this possibility, right?

Personally, I am glad it happened. I have added it to my personal bucket of Gotchas to watch out for.

By the way, I just had the wrong controller! :joy:

2 Likes
14

It took unusual courage to report back: thank you!

But, no, you’re not “being stupid”. You learned something you didn’t know before, which is always valuable.

Now you can move on to the next part of the puzzle.

Good lasing!

4 Likes