Machsupport Forum
G-Code, CAD, and CAM => LazyCam (Beta) => Topic started by: DRP on September 17, 2007, 05:52:23 PM
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Hi all
Just wondered if anyone has had this problem.
I draw a square box in a cad program and convert the corners to arc's radius's, so in other words its a box with round corners.
I save the file off as a dxf file no problem, but when I import to Lazy Cam it renders the box with only 1 or 2 of the round corners. The other corners are replaced with diagonal straight lines.
Does anyone have any idea's on this please? I have the sample dxf files if anyone needs to look.
Many Thanks
Dave P
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Please post the DXF and I will see what the importer code is doing.
thanks
Brian
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I'm having the same problem. I imported what appears to be a clean plain .svg file from inkscape and it converts curves to lines. When I do a spiral it's made up of lines! Frustrating!
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Please post a file or mail it to me and I will have a look at it
Thanks
Brian
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Hi Brian, ok here it is had to rename it .doc to upload. thanks. Rob
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I've messed with all the inport seting and I can't get any arc into LC :(
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the same file wil import correctly into corel
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Can import correctly into SimplyCam
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Brian, with all due respect...I have gone back nearly a years worth of posting only to realize that this problem has existed for at least that time based on threads you've answered. As someone new to cnc, the stuff I'm trying to import is baby talk to most all here. I've tried as many ways to get a simple file into lazycam as some of the people posting. I recently purchased Mach 3 and would gladly fork over the lazycam fee, if only I could get a simple circle to import in just 1 file format. As it looks now I need to find a lazycam replacement??
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Hello:
If you would like to use an other Cam program please checkout SheetCam or Bobcad...
The problem with Lcam is that we are having trouble with the Bulged polyline and Splines (Ths is not Lcam code but code that we have licensed from an other software company). They have fixed a few of the loading problems and I have found a small math error that will make an Arc's vanish. I have added code in the Rev that I have been working on to fix this problem..
Now for your file:
I have looked at your file again and it will not load.... So I tested the file with Feature Cam and it could not load the file! It says "Corrupted file". If a 15,000 can not open your DXF I don't think I will ever get it to work... So if you would like to post a new one that is openable I would be happy to look at it. IF you would like you can also mail me off list to get me the file.
Thanks and Looking for a DXF that I can open
Brian
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Hi
I've experimented in Corel Draw 12, outputting in all its many file formats and importing into LazyCAM. I find that ellipses are rendered as octagons in some cases. This seems to be because they are output as four Bezier curves, and LazyCAM treats each of these as three straight lines. Outputting from Corel as a WMF gives the most accurate rendition - better than its own native formats. The oldest DXF formats (AutoCad 2.5, from memory) work well, but the newest are hopeless. If you see jagged lines where you expected curves, I think it's because LazyCAM isn't interpreting Beziers correctly.
Is GCode the only graphical language that doesn't support Bezier curves? It seems to me it could make for much better import of DXF and other files. The Bezier probably wasn't invented when GCode started out, but these days it is the way almost all fonts and graphics packages work.
Imagine if you could code:
Gnn X x3 Y y3 Ax By Cxx Dyy (Move along a Bezier curve to x3,y3 with control points x,y and xx,yy)
This would replace anything up to hundreds of lines of G1s.
I have written a 2D Bezier macro for Mach3, but native support would be much more elegant, so that LazyCAM could post it directly. We have all sorts of canned cycles, so why not Beziers? They are extremely easy to scale, rotate, stretch or skew and fast to draw. Much better than circular arcs which are so very restricted.
From the perspective of a CAM programme, I can see that there are some complexities, such as offsetting by tool radius. For Mach3 there might be issues of calculating acceleration and deceleration, but it could convert the curve to a sequence of G1s internally for this purpose.
Other parametric cubic splines exist with, in some cases, valuable properties, but none are as universally found in graphic files as Beziers.
As a newcomer to this business I don't know if this has ever been suggested before and, perhaps, very good reasons exist why it couldn't be done or wouldn't be worthwhile. If so, I'd love to know.
Regards
Chris Lusby Taylor