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Drawing import tab guidelines

Posted: Fri Jul 06, 2018 2:20 pm
by motoguy
I've been having issues with Sheetcam creating loops/overlaps on imported drawings. I create drawings in Corel 2017, join curves, reduce nodes, make sure paths are closed, etc. The drawings look fine in Corel. Still, sometimes Sheetcam will create overlaps on corners, etc. I can play with some of the settings in the "Drawing Import" tab, and it will help with some of these issues. That is expected, as that is part of the issue Sheetcam has to deal with is dxf export from a variety of sources.

My direct question is, what are some good "drawing import tab" guidelines (in my case, for plasma cutting)? I've typically left it with the default settings (measured in single-digit thousandths). In the manual it's suggested that "Max detail reduction error" can be as high as 0.020" for Plasma. What would be real-world suggestions for the other settings? With (good) air plasma tolerances being in the 0.015" range, should I use that number in all my values?

Re: Drawing import tab guidelines

Posted: Mon Jul 09, 2018 1:18 pm
by Les Newell
I'd suggest using something like 0.010 for the detail reduction with up to twice that for the arc fitting tolerance. I'd keep the link tolerance pretty small, say 0.001" - 0.002"
SheetCam should not be able to create overlaps. Generally if you have overlapping outlines they will be in your drawing. Could you post a job file and drawing that demonstrate the loops issue.

Re: Drawing import tab guidelines

Posted: Sat Aug 04, 2018 8:21 pm
by motoguy
Here's an example. The "loop" is created in the lower right hand quadrant, immediately to the right of pierce point S20. I've attached a copy of the SVG file as well. Looking at the SVG file in Corel, there is no issue at that point. There are a couple of nodes close together (about .020"), but no overlap, no loops, lines are connected, etc. Sheetcam appears to be creating the loop in this instance. I've attached a screen shot of the area in Corel, so youc an see the nodes in question.
Capture.JPG
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Re: Drawing import tab guidelines

Posted: Sat Aug 04, 2018 8:22 pm
by motoguy
Capture3.JPG
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Capture2.JPG
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Re: Drawing import tab guidelines

Posted: Sun Aug 05, 2018 1:22 am
by WyoGreen
MotoGuy,
I opened your .svg file with my version of CorelDraw, and that loop was in the .svg file you posted. Have you tried opening the .svg file with CorelDraw after you've exported it from CorelDraw ?

Steve

Re: Drawing import tab guidelines

Posted: Sun Aug 05, 2018 2:14 am
by WyoGreen
Motoguy,
I went thru your .svg file and cleaned up a few spots I found with problems. I won't swear that I got them all, but see if this file works better for you.
Moon Fairy2.svg
(9.43 KiB) Downloaded 185 times
Steve

Re: Drawing import tab guidelines

Posted: Sun Aug 05, 2018 8:56 pm
by motoguy
WyoGreen wrote: Sun Aug 05, 2018 1:22 am MotoGuy,
I opened your .svg file with my version of CorelDraw, and that loop was in the .svg file you posted. Have you tried opening the .svg file with CorelDraw after you've exported it from CorelDraw ?

Steve
Yes, I re-opened both the .cdr and the .svg file, and it's clean in both of them.

Re: Drawing import tab guidelines

Posted: Tue Aug 28, 2018 7:45 pm
by motoguy
I ran into the issue again today, and was able to see what WyoGreen saw. File looks great as a native .cdr file, but will export with small errors when I save it as an .svg. Using Corel2017. Odd.

Re: Drawing import tab guidelines

Posted: Thu Nov 08, 2018 5:04 am
by motoguy
From what I've been able to tell, it has to do with how close nodes are in the drawing. When I have a Corel drawing with a couple of very close nodes, I get this issue. I've been trying to remove "very close" nodes in my drawings in Corel, and it seems to have fixed the issue.