You can cut a shape that has a different profile specified for the left and right side fo the cutter.
The only requirement is that each profile have the same number of segments making up the left and right profile. This is necessary because the segment count controls when the hot wire hits specific locations in the cut and you want this coordinated so the cut will complete properly.
The trick is in getting the DXF files for both the right and left side of the cut to have the same number of segments.
I first determine which profile will be my base drawing, I then trace of the base drawing using the procedure outlined below to control the segment count and control the cutting path. Your traced drawing will be your cutting path with the cut starting where you started the tracing and ending where you end the tracing. I then follow the procedure below to get the second profile to contain the same number of segments, you should then be able to do the cut you desire.
The process I use to control the number of points in DXF drawing that I want to use with the foam cutter is as follows:
I load the DXF file into CadWorks (or the CAD program of you choice) and basically I trace the base drawing on a new layer with a polyline tool controling where I add nodes with the polyline tool. I draw just as if I was drawing the desired cutting path.
1. Loaded the file you want to use as the base drawing into CadWorks and trace over the drawing on a new layer with enough polyline segment to accurely represent the curves and lines.
2. Confirm the number of segments that are on the traced layer so you have this value when you work with the second profile.
3. Delete the base drawing leaving just the tracing and save the modified DXF.
4. Load your second profile into CadWorks
5. Create a new layer on the drawing.
6. Turn on ortho\snap\endpoint (this make tracing the original very easy)
7. Make sure the new layer is current and active and then with the poly line tool, trace the base drawing. Start the polyline where you want the cut to start and work your way around the original drawing following the desired cutting path. Draw just as if you were drawing the cutting path.
8. Remember you are trying to coordinte the second proflie with the first, so start the polyline at the same point and make sure the same number of segments are between key points like a 90 degree turn. You want the cutting wire to hit the cooresponding points of each profile at the same time. This is controlled by the segment count between these key points.
9. When the tracing is complete, delete the original drawing and any extra layers, leaving just the traced layer and polyline.
10. Save the second traced DXF
Now I have a new DXF files that has the controlled number of segments that match.
Here is a youtube video that demonstrates the tracing process. All you need to is manage the segments as well.
http://www.youtube.com/watch?v=7QPP15PRYzE
Another thing to consider is that unless you get the cutting towers as close to the cutting towers as possible, there could be a blending effect between the two shapes. It would be most visible on the square end of the cut. I actually designed my machine so I can adjust the distance between the towers to allow for this concern.
Hope this helps
Dave
www.foamwork.net