This is a frame tube mitering fixture that I designed and fabricated. It allows me to accurately machine the tubes to length (using the center to center dimension), while insuring that the miters on each end of the tube in the correct orientation to each other. It utilizes a horizontal milling machine and a rotary table. The center line of the tube, the center line of the milling machine spindle and the center line of the rotary table all meet at an imaginary point in space. The miter angle is set by the rotary table. The tube length is set by a back stop on a calibrated rail. The miter phase orientation is held in place by an anvil on the back stop that mimics the mating tube.
