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How about a utility for cutting fabric with a rotary blade?

Posted: Tue Dec 29, 2015 2:40 am
by Moana
I've extensively used the drag knife utility from Sheetcam. Good work Les. Unfortunately, drag blades are tough to use on strong fibers like carbon fiber. One incomplete cut and it snags the material and ruins it. Not to mention, the table must be super precisely level and the blades wear out really fast since you cut on just one little spot on the blade. I'd like to add a stepper with a pneumatic pen and an 18 mm rotary blade on the end of it. The drag knifes are passive turning, but I'd like to have a stepper precisely turn my blade and come back down onto my fabric. I made a passive turning 18 mm rotary blade (out of my old drag knife tool) and it worked fairly well. The problem is you need to cut with adjustable pressure, not a z depth. That will make the table more forgiving like expensive Gerber ply cutters and usable for things like cutting decals, etc. I see a big market for this utility. If someone will make the utility, I'll buy it! (and so will others). This is my first post on here, so I hope I am posting in the right place :D

Just some thought, I think the drag knife utility is a good start with just some conversion of the routers rotation being sent to a separate stepper, rather than to the x and y steppers. Seems simple in theory, but I'm not a programmer.

Posted: Tue Dec 29, 2015 3:05 pm
by Les Newell
You can already do this using the 'Mach3 tangential' post processor. Set up the cut paths using a milling/routing tool with no offset. The post outputs the normal X,Y,Z coordinates with an extra A coordinate for the angle. Set up your rotary axis so one full rotation is 360 units. If you are using Mach3, configure the A axis as a linear axis, not rotary. Mach's rotary compensation will be confused by SheetCam's code.