Straight Lines instead of G2 or G3

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suntzu626
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Model of CNC Machine: Accu-Cut Model 510

Straight Lines instead of G2 or G3

Post by suntzu626 »

I'm trying to generate G Code for a series of ellipses cut out of some material on my Accu-Cut Model 510 router with Mach3 and no matter what post processor I use, even if it has the G2 and G3 commands, the G Code is still generated as thousands of tiny straight lines rather than two clean arcs. Don't know if it is due to how I drew the ellipses or generated the tool path. I've tried a bunch of different PP files and none seem to give me the arc moves. Please help.
Attachments
order7237.zip
Cut2D project file and end G Code from Fanuc16 ATC Arcs (inch) PP
(177.66 KiB) Downloaded 173 times

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Adrian
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Re: Straight Lines instead of G2 or G3

Post by Adrian »

The shapes you've created are made from bezier curves not arcs so no arc commands will be generated. If you go into node editing (press N) you can look at the spans and nodes to see how they're made up.

The attached file shows two circles, one made from beziers and one from arcs.
Attachments
arc test.crv
(104.5 KiB) Downloaded 208 times

suntzu626
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Re: Straight Lines instead of G2 or G3

Post by suntzu626 »

Ok so how would I draw these shapes in a way that would give me arcs?

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Adrian
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Re: Straight Lines instead of G2 or G3

Post by Adrian »

I doubt you will be able to but if you want to try you can go into node edit and hover over each span and press A (or right click) to convert the bezier span to an arc.

I don't see how you're going to get a shape like that with an arc though I'm no expert with them.

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rscrawford
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Re: Straight Lines instead of G2 or G3

Post by rscrawford »

You can convert your curves to arcs by using the 'fit curves to vectors' tool. This allows you to fit arcs or bezier curves to any vectors you select, and you can choose the tolerances

edit, I just saw that this was posted under Cut2D. Not sure this tool is in Cut2D.
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suntzu626
Posts: 4
Joined: Thu Nov 15, 2012 10:02 pm
Model of CNC Machine: Accu-Cut Model 510

Re: Straight Lines instead of G2 or G3

Post by suntzu626 »

I tried drawing the ellipse in a different program with arcs and not bezier curves then importing the .dxf file into Cut2D and the G Code comes out the exact same way: all G1, not G2 or G3.
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order7237NEW.zip
(2.77 MiB) Downloaded 152 times

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Adrian
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Re: Straight Lines instead of G2 or G3

Post by Adrian »

Go into node edit and look at those new shapes. There are hundreds of nodes not arcs.

The attached file is the closest I could get to your shape using arcs.
Attachments
single arc oval.crv
(51.5 KiB) Downloaded 185 times

suntzu626
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Re: Straight Lines instead of G2 or G3

Post by suntzu626 »

That shape works, thank you so much for the help :)

aironeous
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Re: Straight Lines instead of G2 or G3

Post by aironeous »

This is quite annoying to not have this functionality in cut2d. I'm trying to do the butterfly puzzle and simply profiling half the shapes becomes a 1 megabyte gcode file for the HAAS mill at my school. At least I know the problem now.

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Adrian
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Re: Straight Lines instead of G2 or G3

Post by Adrian »

The functionality is all there in Cut2D it just has to be done manually rather than using a one click tool.

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