I am wondering if it is a swivel knife for a reason...
There are two kinds that I am aware of. "Theta" and Follower. (I made up the theta name based on the math it uses)
The Follower type is like the kind you would buy at an art store and is used for cutting things like Frisket/Mask by hand. A fancy Xacto if you will. The blade point follows behind the the axis or handle. With this type, I think you would get a lot of backlash.
the other type "Theta" is the kind I use at work. This type, the firmware calculates the Theta movement (Stepper driven angle derived from the tangential motion of the Cartesian X,Y movement) To do this on a 3D printer that isn't already set up to figure that out, you would need to rewrite a chunk of the firmware. Essentially, it is adding another axis to the mix
Here is what I have at work. I have looked into rebuilding the controller, as this one is exceptionally dated. But I don't think my coding skills are up to the task of multi coordinate positioning. Probably would be better to just add a powerful enough laser.... it would be simpler.
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http://www.neurascenic.com/show/RostockMax/Swivel.JPG[/img]
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http://www.neurascenic.com/show/Rostock ... _Table.JPG[/img]
I am a fool entrapped within my own wisdom.