Weird behavior: Top line of design skipped (Ruida 6442G 60w 7050 red-black)

I’m experiencing this odd behavior with v0.9.11 of LightBurn when paired with my Ruida controller. For some reason, if I use “User Origin” or “Current Position” when starting a cut, the topmost x-motion cut is skipped. In an example, I tried making this very simple design (10.25-square-weirdnolinetop.lbrn (6.0 KB) which is a quilting pattern cut in 1/8" acrylic.

If I attempt this cut in user origin or current position, the topmost line doesn’t cut. I also tried “send” to the ruida and cut it that way, and the line is also missing. If I switch to absolute coordinates, the line cuts fine.

Thinking this was quite an oddity, I switched to a different design, the “wrenhouse” that was posted on facebook the other day. Low and behold, the same problem was occurring on the top two objects in the cut, but not the bottom object, all four of its sides cut as expected. NOTE: this design’s hole shapes are wrong, if you cut it, the mortises will be too loose. wrenhouse-eigthinchply.lbrn (39.0 KB)

My normal process is to make a shape, select it for cut, and make sure that it is offset from the 0-lines (i.e., upper-left corner would be (1,1) as opposed to (0,0).

I reset the ruida controller hoping that might help but the problem persisted.

I’d love any feedback from the forum on what could possibly be causing this weird issue. Thanks in advance!

Where is your laser head when you try to use the ‘Current Position’ or ‘User Origin’ mode?

Your design has a kerf offset, so if you were right against the upper edge of the work area, it would not be within the bounds of the machine. Having said that, it’s possible that the kerf offset is not being included in my bounds for the job, which could cause it to be omitted as well, though I would expect that to happen for all the sides of the square, not just the top.

The WrenHouse design also has kerf offet cuts (and a 500ms pause at the start / end of all of them).

When I was using “User Origin” mode, I was moving to a part of the material that wasn’t cut. It wasn’t close to the motion bounds of the machine, it was closer to the center of the table, so I don’t think the cut would have gone out of bounds. If you tell a ruida machine to make an invalid move, will it continue the job or error?

It will usually warn, then cut the part that’s within bounds. It’s very likely the kerf offset not being included in the job bounds. I should be able to fix that without too much trouble.

In the meantime, a simple fix would be to make a rectangle around the project, 1mm larger on all sides, set it not to output. It will be included in the frame / bounds, but won’t cut.

I’ll go check whether a nonoutputted rectangle around the work solves the issue, and also if eliminating the kerf also solves the issue. Give me 10.

OK, I think that your original mention was correct – I could not reproduce the issue if I went center-table and tried the user origin cut. So, I went instead back to absolute 0,0 and retested with user origin and the issue came back.
I then removed the kerf, issue went away.
I replaced the kerf, but offset the cut inside of a larger bounding box that wasn’t outputted, problem went away.

So I do think what is happening here is that I was wrong about the test yesterday and I must have been moving out of bounds. The Ruida controller, rather than alerting me to this, just skipped things that were out of bounds (ugh!)

Thanks for looking into this.

If I get the frame size correct it should warn you though, so that might help. I’ve logged it as a bug - I’ll see if I can repro it and fix.

1 Like

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.