Very weird import problems.

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Pats
Posts: 3
Joined: Sun May 21, 2017 12:01 am

Very weird import problems.

Post by Pats »

Hello, this is my first post here, I'm trying to figure out why exactly is Sheetcam adding nodes to my SVG import.

I'm attaching the SVG file I'm using, it's a simple "test" text, already in curves, and as we can all see it looks like it should look.

http://gyazo.com/7832c9240fffddb0fc2cc38421918baa

This is how it looks opened in Illustrator.

https://gyazo.com/8f41f1609a032dada639f8a300890563

This is how it looks in Inkscape.

https://gyazo.com/a5267929352bc18fd09c8141e7b2153e

And this is how it looks in Sheetcam. I have no idea why, I have tried saving in different SVG versions, everything produces the same result - it looks fine everywhere else but in Sheet cam. I am slowly running out of things and ideas to check, so I ask for your help here, maybe someone has seen this before? The file is attached for everyone to see/test.

I originally saw that issue with DXF import (which ironically looked much better than SVG import in terms of how S curves were produced) but I still don't know why Sheetcam actually adds nodes. Because the same SVG opened in both Illustrator and Inkscape has literally the same nodes in the same position, and opened in Sheetcam has more nodes in different positions. I have searched the internet and the only reference to this is with people importing DXF's from Corel and Corel doing some wonky stuff with the saving.



Thank you for all input and suggestions.
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Les Newell
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Joined: Thu May 11, 2006 8:12 pm

Post by Les Newell »

What size is that text? SheetCam tries to minimize nodes and with the default settings it can be a bit aggressive for small text.

Go to Options->application options->drawing import. Halve the arc fitting tolerance and make sure the minumum segments for arc fitting is at least 5. Now reload your drawing. You may need to experiment further to get the best compromise between the number of nodes and accuracy. Note that you will probably end up with quite a few more nodes than in the original drawing. That is because g-code only understands circular arcs. Any curves that aren't circular have to be broken up into segments.
Pats
Posts: 3
Joined: Sun May 21, 2017 12:01 am

Post by Pats »

Hello,

The text was small, and the drawing import changes you proposed fixed the issue entirely. Thank you for that! It's awesome to have it working finally. Will it not cause any issues with large texts? As in, right now I have 0,04mm fitting tolerance and 5 segments for arc fitting, and accuracy is awesome. Will it cause any trouble with bigger things, though?

Thank you!
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Les Newell
Site Admin
Posts: 3661
Joined: Thu May 11, 2006 8:12 pm

Post by Les Newell »

If you have large drawings with lots of curves you might find your g-code files get pretty big and it may take a while to calculate the tool paths. Some machines run quite rough with lots of short nodes. You will have to try it and see how your machine handles it.
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