Real-time in-process gauging of mill-turned components

A new, hard-wired, touch probing system allows sliding-head CNC lathe users to measure turned and milled features quickly on every component after machining, while it is still in the counter spindle and before ejection. Believed to be the first real-time, in-process quality control system for 100 per cent inspection of critical dimensions on sliding-head lathes, Rugby-based subcontractor, Davromatic Precision, which uses a number of Star sliding-head lathes and helped m&h UK develop the inspection technique, reports a 20 per cent productivity increase, 10 per cent reduction in scrap and two hours’ extra unmanned running per day. The gauging arrangement, which employs a fixed probe mounted on the headstock, is also suitable for use on fixed-head, bar-fed, twin-spindle turning machines, provided that the counter spindle is able to move in the X-axis as well as in Z to effect the measuring cycle. Particularly when hard material is being cut, insert wear can rapidly lead to parts drifting out of tolerance, requiring manual intervention to update tool offsets. The ability to inspect such components continually, avoiding subsequent handling, and to update offsets automatically, reduces manufacturing costs, increases output, improves accuracy and reduces scrap to virtually zero. With the m&h equipment fitted, the machine will shut down immediately a preset limit is exceeded, so a safety factor when changing inserts, for example, is not needed. Expenditure on tooling is consequently reduced, as cutters can be used until they fail.