We include the "Rotary Wizard" in our 5 axis bundles. It takes a flat 2D design and "wraps" it around a round object. It does it by recalibrating the rotary axis to set the number of steps to move the SURFACE of the cut one inch. You simple input the pipe size and it does the rest of the math.
So you draw it flattened out, You bring it into SheetCAm with the drawing width being the circumference of the pipe (shows up in the Rotary Wizard window) and you run it in rotary mode. The Rotary Wizard also does rectangular and square tube by indexing 4 times to cut each side.
So where do you get the magic flat layour of a birdsmouth or an ellipse where two pipes join at different angles?
If you have SolidWorks then you just draw it in 3D and unfold it to a flat 2D. For those of us not wealthy enough to own Solidworks, take a look at
Digital Pipe Cutter Software. Will let you design the joints, see them in 3d and then (here is the important part) lets you export in DXF into Sheetcam, It brings across a bunch of grid lines and stuff that you can ignore in SheetCAM and it has in inside and outside toolpath. The Software is not terribly expensive for what you get, (around $500.00) You can get a demo that will only draw the cut paths if the angles are 53 degrees but everything else works. Coolest thing it being able to see the joint(s) in 3d and spin them around and stuff.
If you just HAVE to have a template you can print the design out and wrap it around the pipe and cut by hand but then who needs a CNC plasma cutter to do that?
We will have some stuff later this summer to make automated pipe cutting and angled tubing cuts even easier and less expensive.
TOMcaudle
www.CandCNC.com