When a turned part has a cross section that is unequal when referenced to its centreline, it is considered to be eccentric. Camshafts often are referred to as the most common of these workpieces, but those parts typically are manufactured on a machine solely dedicated to their production. So what is a job shop to do when an order for a part comes through the door that needs eccentric turning? The answer, surprisingly, may actually start with a milling operation.
The process of eccentric turning is similar to traditional turning only with the addition of another workpiece axis, which is parallel to the centre axis. To produce the eccentric part feature, a cutting tool removes material to the required depth as the part is turned, typically at low speed.
What type of machine setup is best suited to perform an eccentric turning operation?
It all depends on whether the CNC lathe has a milling spindle.
If a multitasking machine is used, we recommend milling the eccentric part or part feature to a near-net shape before using a finish turning pass to complete the feature.