Image not fully engraving (cut off)

Hello,

I am running a standard 50W CO2 “Blue” Ruidia Engraver Mainboard Firmware Version: RDLC-V8.00.58

During the engraving process we have noticed that on about 25% of our engravings, part of the image is cut off (this normally happens with curved images). The image file is a .png file

We first noticed this running lightburn 8, but after updating to 9.04.06 the problem persists.

I have a .lbrn file that we know is an example of the problem (and will do it repeatedly on both a windows and mac) as well as a video of the engraving happening to show what is happening.

We have found that we can fix the problem by rotating the whole engraving 90 degrees and re-engraving, but we are a leather shop so its expensive and time consuming to test every custom engraving to see if it will cause a problem and the waste that will occur from not testing will also be very expensive.

Thanks,
C

You’re likely using the pass-through option, and rotating the image in LightBurn. Rotating an image requires resampling it, and enable pass-through explicitly disables the resampling. Does this sound like the culprit? (I’m not sure what you mean by “curved images”)

With a dramatic rise in the use of “magic scripts”, I’ve updated the next version of LightBurn to handle the special case of 90 degree rotations even with pass-through mode enabled, but until that one is out you’ll have to rotate anything used with pass-through in your image editing software.

Are you by chance dithering the image outside LightBurn and using the ‘Pass-Through’ option and then rotating the image?

If so, don’t. When ‘Pass-Through’ is set to ON, this tells LightBurn to not touch or reprocess the image. When you rotate the image you tell LightBurn to do just that. This causes issues currently being reviewed and addressed by the team.

Could this be what’s happening?

Our current engraving settings for the layer that is having problems is:

Speed: 500
Max power 40
Bi Directional Scanning: on
line interval: 0.042
Scan Angle: 0
DPI: 605
Image Mode: Dither
Number of Passes: 1
Pass-Through: Off

Can you send me the file that’s exhibiting the problem? If possible, also send the image along with it. Email it to developer at lightburnsoftware dot com and I’ll have a look.

For anyone reading along, I suspect I’ve found the issue, but MCC will follow up to confirm or not. The image being engraved is a reasonably simple black and white logo, but it has smoothed edges (anti-aliasing) and the settings aren’t ideal for it.

When I zoomed in on the preview, I saw this:

The image layer is set to 1000 DPI, dithered, so all the smooth shading on the edges of the logo are being turned into lots of tiny dots. This alone would normally be fine, but the image is set to 1000 DPI, and 500 mm/sec. On a Ruida, simple vector engravings will run fine at these speeds, but a detailed image engraving won’t, and because of the settings, this falls somewhere in between. I believe the controller gets most of the way through, but hits a point in the image where the information density is too high and gives up.

Setting the image to Threshold (simple black/white cutoff) produces this in the preview:

The fuzz is gone, meaning significantly fewer commands to process. I also recommended lowering the DPI down to 600 - glass tube CO2 systems can’t hit 1000 DPI anyway, so there’s little reason to run it this high.

Again, this is an educated guess, and I’ll wait for the final result from the original poster, but thought I’d post this in public so others could learn from it.

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