Video: Turn-Mill Probes for Accurate Camshaft Machining
Feature-to-feature accuracy for diesel camshaft segments is possible thanks to in-process probing.
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.
Virtually every machine tool builder lists, as part of a machine's specification, accuracy and repeatability figures. What's generally not given is the method used to arrive at the figures. Though these methods are defined in linear positioning standards, not all builders use the same standards.
Here are some of the tools and techniques for making sure machine tools stay at peak performance levels.
Lockheed Martin’s precision machining of composite skin sections for the F-35 provides part of the reason why this plane saves money for U.S. taxpayers. That machining makes the plane compelling in ways that have led other countries to take up some of the cost. Here is a look at a high-value, highly engineered machining process for the Joint Strike Fighter aircraft.