Part probing isn’t performed on turn-mills as often as it is on conventional machine tools. There are clear advantages for in-process probing on multitasking machines, though. A good example is machining of large diesel engine camshaft sections on a turn-mill machine. After machining, the sections are assembled together to form a completed camshaft.
Each segment has holes positioned around a bolt circle to accept assembly bolts. The bolt circle (thus the center line of each bolt hole) must align with the actual center line of the camshaft segment for proper alignment during assembly. WFL Millturn Technologies (Novi, Michigan) has developed a canned probing cycle for its turn-mills that automatically probes finds the center line of the segment as well as the true centers of the bolt holes, all of which have been pre-drilled undersize. If a bolt hole’s center-line position is not where it needs to be relative to the part center line, then offsets are made to position the tool to the correct location before drilling to final size. The video demonstrates this probing routine.