Sensing Distance from Work Piece

Quality of product depends on the ability to detect the distance of the cutting tool from the Work Piece. The nature of this sensing problem changes depending on the cutting tool.

Plasma Torch

Here is a great article on controlling Torch to Work Distance. The quick story is that voltage between the torch and the work piece increases as the torch gets further away from the material. There is a discussion of building a z-controller here-- some of the content may be helpful. From that is a potential collaborator.