Overlapping lines, messed up preview

[Frankmikalsen]

Hi

I’m getting a weird preview when using “Remove overlapping lines”
I select the 2 pieces, then Distribute - Move-V together.
When I zoom in max it looks like the lines are not overlapping.
But in the preview they are.

What causes this?

Did as the short video posted here.

I tested on another file also with many rectangular shapes. Also same problem.
I’m pretty sure I did this one time and it worked perfect.

Thanks in advance

[ednisley]

@Frankmikalsen

When I zoom in max it looks like the lines are not overlapping.
But in the preview they are.
What causes this?

[Frankmikalsen]

What does mean?

I change the Distance up and down, no distance makes this correct in preview.

VIDEO: Quick Tip - Remove Overlapping Lines

[Quick Tip: Remove Overlapping Lines] Our Quick Tip Video this week is on the Remove overlapping lines setting, which tells your laser to cut shared lines in your designs just one time. This is among the handiest settings in the LightBurn toolkit, and one I’ve saved to my personal default Optimization Settings. It doesn’t come into play for every project, but it’s painful when you start a job it would have been helpful for, only to realize you forgot to turn it on. For more infor…

[ednisley]

@Frankmikalsen

What does mean?

You asked why the not-quite overlapping lines disappeared.

I pointed out the “Remove overlapping lines” setting is enabled with a tolerance that (almost certainly) covers the “zoom in max” distance between the lines.

So LightBurn is doing exactly what you told it to do: remove parallel lines that are no more than a small distance apart.

I’m smiling because I have often run into a similar situation: a program did what I asked, not what I expected.

[JTR (Tyler Raps)]

Based on the rounding of the lines in your preview it looks like you have a Kerf Offset enabled. LightBurn applies the Offset before Removing overlapping lines, so that’s why the lines are not being removed (the Kerf Offset causes them not to overlap within your specified tolerance). If you share your project file, we can verify whether that is the case.

If you need that Kerf Offset for other parts of your design, try using Docking to move the parts together with a padding that matches 2x the Kerf Offset value — ie, if your Kerf Offset is .5, you’ll need 1 mm of padding.

Docking Tool - LightBurn Documentation

To answer the question you PMed me: Optimization Settings are saved per-file, so you need to save the file after making any adjustments. Otherwise, when you re-open the file, the Optimization Settings will revert to whatever they were when you last saved it.

[Frankmikalsen]

These 2 I am moving together with Alt+Shift+V
This is how it looks after that and zoomed in all the way.

Overlapping lines distance 0.025mm. Then it looks like this in the preview, cutting time 2:09. This goes all the way up to 0.175mm

From 0.200mm it looks like this, and the time is down to 2:01.
There are more like this on the project, so ther wil be more difference in the time.

edderkopp test.lbrn2 (22.1 KB)

[Frankmikalsen]

I set Kerf to 0 and I looks almost perfect.

[onhiatus (Tony Jones)]

When I move objects together, overlap corners, etc and then zoom all the way in, it’s not always perfect. This drove me crazy until I used the ruler tool to try and measure the offset - it showed “0.00mm”. I believe we’re seeing an artifact of rounding, and at cut time they cut fine.