Patent ID: 8083444

Claim:
A method of determining a center axis of a pipe for machining an interior curved surface of the pipe with a machine head having a spindle and a cutting tool, the method comprising: mounting a pipe to be stationary on a stationary work support; mounting a touch probe to a machine head; positioning the machine head adjacent an open end of the pipe while holding the pipe stationary on the stationary work support; determining the center axis of the pipe using the touch probe mounted on the machine head by shifting the touch probe in linear directions along two or more separate axes while holding the pipe stationary on the stationary work support to touch opposite portions of a curved surface at a plurality of points and calculating the location of the center axis of the curved surface based on the probe shifting in the two or more separate axes; centering a spindle axis of the spindle on the center axis of the curved surface while holding the pipe stationary on the stationary work support; removing the touch probe from the machine head and mounting a cutting tool to the machine head; and positioning the cutting tool to engage the curved surface and in-feeding the cutting tool relative to the stationary pipe to machine thread on the curved surface while holding the pipe stationary on the stationary work support during the positioning and the machining.