Plasma Torch Height Controller

In a senior capstone project sponsored by Victor Technologies, I was a part of a group of four that designed two iterations of prototype actuators for precision z-axis control of a plasma torch. We designed a light, compact and durable system that could be mounted on a six-axis robotic arm to enable cutting of three-dimensional parts. This tool improved cut quality by accurately controlling the working distance between the end of the plasma torch and the workpiece. Feedback was provided by the relationship between voltage drop between the torch and the part and working distance. Our controller was a robust commercial controller adapted to work with our system. Our sponsor, Victor Technologies, is currently moving forward in bringing our product to market. Upon successful completion of this project, our group was awarded the Dartmouth Society of Engineers Prize for outstanding performance on a capstone project.

My primary roles were leading CAD design and fabrication, analyzing cut test results, and sourcing parts. All parts were machined using CNC mills and lathes. The system was designed for fast and easy assembly and disassembly.

In the video above, you can see our actuator used to cut an irregular surface while mounted on a gantry-style CNC table. Typical irregularities experienced in robotic plasma cutting are smaller and higher frequency than displayed above. Our actuator was designed specifically for robotic arms, but for this demonstration, this video shows the actuators ability to maintain proper working distance while cutting irregular parts.

The above video demonstrates the actuator in use on a six-axis robot. The robot is preprogrammed to cut square pieces and the actuator automatically maintains the proper working distance throughout the cut. This ensures a high quality cut.