[KSky]

I am trying to learn sheetcam as it seems that a lot of people are using it for various cutting operations. I have a simple shape with two squares next to each other. Sheetcam draws the toolpath like the screenshot below But the resulting Gcode has the cutter moving in an arc between the two.

See...
N0170 G02 X-0.0625 Y1.0000 I0.0000 J0.0625

When I pull my two squares jpeg directly into mach3, it cuts the two squares just like I would expect.

What am I missing here? Attached is my DXF file of the two squares outlines and a screenshot of sheetcam.


Generated GCode up to this point.
N0000 (Filename: scTwoSquares.tap)
N0010 (Post processor: Mach2.post)
N0020 (Date: 09/12/2005)
N0030 G20 (Units: Inches)
N0040 G40 G90
N0050 F1
N0060 (Part: TwoSquares)
N0070 M6 T4 (1/8 End Mill)
N0080 G43 H4 F8
N0090 M04 S3600
N0100 M08 (Flood coolant on)
N0110 (Process: Outside offset 0, 1/8 End Mill, 0.25 " Deep)
N0120 G00 Z0.1575
N0130 X1.0000 Y0.9375
N0140 Z0.0197
N0150 G01 Z-0.1250
N0160 X-0.0000
N0170 G02 X-0.0625 Y1.0000 I0.0000 J0.0625
N0180 G01 Y2.0000

[cncadmin]

You have it offsetting to the outside, ether you have to give it some space in between or use no-offset.

[trevorhinze]

What you have drawn and what Scam is recognizing is two seperate squares. It is going to cut these out one at a time and as a result the toolpath used to cut around the outside of one square will actually go right thru the corner of the other square. If you want the shape to be cut out as one part rather than two you need to use pedit to turn join the 2 squares into one polyline first, then save the file as a .dxf for import into Sheetcam. I will include an attachment of your drawing which I have modified as mentioned above, give it a try. I actually had to trick it by putting a very small seperation where the two squares seem to meet. I left a very small gap in the middle so that the paths do not all meet or cross at one point. It is a very small offset and you will only be able to see it if you zoom way in. Now sheetcam likes the shape and cuts all around the outside in one nice path...Hopefully that is what you were trying for! Hope that this helps. And one other thing remember is that when you are looking at the toolpaths that sheetcam generates on the screen you will always see what seems like an arc wherever there is an outside corner no matter what its angle, but when the part is cut you will in fact end up with a square, or whatever angle corner. It is more efficient and better for the bit to have it go around the corner in an arc rather than come to sudden stop and then change direction to produce a square corner, assuming you are using a milling type cutter, if you are plasma cutting then this would not apply. Good Luck!

[KSky]

Thanks. I was more playing around learning how this all works than trying to cut two squares. Seems like sheetcam does the arc thing whenever you need to cut around the outside of a sharp angle. Kinda cool, but it doens't show up exactly that way on the toolpath display.