Gcode for CNC 2D engraving

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CD-
Posts: 9
Joined: Wed Jun 26, 2019 12:22 am

Gcode for CNC 2D engraving

Postby CD- » Sun Aug 18, 2019 10:15 pm

I'm a beginner & need help. I have a sketch that I want FreeCAD to create 2D gcode so as to do CNC engraving. I seam to only find 3D engraving. At present I'm exporting to dxf format & using Pycam to create the Gcode. This has it's own problems in that the way Pycam imports/interprets the Autodesk DXF 2D format is not all that correct. E.G. Concave corners of the sketch come out as straight lines etc. So I'm looking at FreeCAD to create the Gcode. Any suggestions please as I cant seam to find an appropriate forum post. Thanks
chrisb
Posts: 17585
Joined: Tue Mar 17, 2015 9:14 am

Re: Gcode for CNC 2D engraving

Postby chrisb » Mon Aug 19, 2019 1:05 am

Seeing your other post I guess you have a ShapeString which you want to engrave. Have a look at the Path workbench, it can directly engrave ShapeStrings.
CD-
Posts: 9
Joined: Wed Jun 26, 2019 12:22 am

Re: Gcode for CNC 2D engraving

Postby CD- » Mon Aug 19, 2019 7:29 pm

In this situation I'm doing plaques for a men's shed & it includes shapestrings & sketch boarders, plus some special sketches. This is my starting point as the shed is doing it currently, Oh so crudely, on the cnc router machine. Eventually I'm want to do 3D carving but 2D is sufficient for the time being. As per the image. I find I have to keep curved & straight lines separate so that the 2D dxf file exported doesn't convert the cornes as straight lines once imported into pycam. All in all I'd like to generate it all out of FreeCAD. That is if it's up to it. Ive also tried dxf2gcode converter but it puts a round into the corners of a square corner, maybe because I know this less than pycam.
Attachments
Plaque sample.jpg
Plaque sample.jpg (91 KiB) Viewed 205 times
CD-
Posts: 9
Joined: Wed Jun 26, 2019 12:22 am

Re: Gcode for CNC 2D engraving

Postby CD- » Mon Aug 19, 2019 8:01 pm

I should also say I'm using up to a 4 mm milling bit & cutting 2.5 mm deep. In another project I'm using 30 & 60 degree carbide straight single flute engraving tools & cutting 0.2 mm to 0.6 mm deep. these last tools I'm not even sure how to load the tool into the tools list.
RatonLaveur
Posts: 303
Joined: Wed Mar 27, 2019 10:45 am

Re: Gcode for CNC 2D engraving

Postby RatonLaveur » Mon Aug 19, 2019 8:20 pm

Yup. Go to PathWB. Pick the Shapestring, roll down the Path Menu and use the "FromShape" tool. This will produce raw Gcode from your strings.

For profiling the plaque, I'd recommend padding it to some thickness. Then using the profile face tool in PathWB.

Hope this helps.
CD-
Posts: 9
Joined: Wed Jun 26, 2019 12:22 am

Re: Gcode for CNC 2D engraving

Postby CD- » Tue Aug 20, 2019 8:40 pm

thanks heaps. I'll give it a go.