Some curves aren't smooth

Hi, new to using LightBurn

So I’ve been trying to cut rectangle objects with rounded curves, but only half of them are being cut correctly. The other half (always opposite to the correctly cut ones) are like so:

I’ve tried reducing cutting speeds, but results are the same. All the time

Materials that I’ve tried: 1mm cardboard, 1mm leather, 0,1 mm leather, 6mm MDF. Always the same outcome

Software: LightBurn latest version (currently on trial)

OS: Mac OS latest version Sonoma

Machine: Zbaitu 20W.

Connection: USB.

Please help?

You “reduced” cutting speed, what speeds ? How fast are you running?

I could well be wrong but that looks like backlash in one of your axes. I’m sure someone with more experience will be able to confirm one way or another.

The speed cut for layers. I’ve been using 300 mm/m, sometimes 500 mm/m. (Better for diode)

But it doesn’t matter if I’m cutting using 500mm/m or 3000 mm/m, the results are the same

I understand what you’re saying, but no matter if start cutting horizontally or vertically, the results are the same

Have you noticed any other problems with corners ? How does a square look? Do you get good corner convergence? It’s opposite corners, often that points to a mechanical issue. Perhaps a little more testing. Push the speed up even more and see if you can coax the problem out.

Mmmm… no, the only problem with corners are when specifically trying to cut a rectangle with rounded corners.

I’ve tried both importing a SVG from Adobe Illustrator and drawing my desired shape from inside the LB software, however, it keeps happening

As for your other consideration, squares are perfect :slight_smile:

I’ve engraved and cut squares, words with rounded letters, no problem. Haha

As for a possible mechanical issue, I’ve tried cutting both horizontally and vertically, but the “opposite side” that’s getting it wrong is always the same, no matter the orientation. If it was a mechanical issue, wouldn’t the problem be “inverted” every time I switch orientation?

As for cutting speed, I’ve increased up to 3000 mm/m to cut a shape the size of a small wallet, still no change

“As for a possible mechanical issue, I’ve tried cutting both horizontally and vertically, but the “opposite side” that’s getting it wrong is always the same, no matter the orientation. If it was a mechanical issue, wouldn’t the problem be “inverted” every time I switch orientation?”

So if you rotate the shape 90 degrees to the right the problem corners rotate as well? Or is it the same upper right and bottom left corner each time ?

If it was a mechanical error then it would same two corners each time no matter the orientation. Upper right lower left.

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Sorry, English isn’t my native language — you’re absolutely right. Apparently it is a mechanical error. Probably on the X axis, I presume.

I’m not an engineer, but I’ll try reassemble it again.

Thanks @soniclab :slight_smile:

Here is some guidance on things to check, I guess some aspects also apply to your machine:

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Thanks, @misken ! You and the two other members helped me a lot.

It was a simple matter o tightening the X axis belt. It was a little loose.

The 20W Zbaifu machine is a powerful one but with little to no instructions. But it’s all good now.

Here is an image of the final result after tightening the X axis belt

The circles are better also

Thanks guys God bless you all

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