Finding stability with 'super diagram'

Dr. Tony Schmitz at UNC Charlotte produced a modified stability lobe diagram, including restrictions on surface location error (SLE), to describe the effect of milling dynamics on the finished workpiece. The SLE was specified to be no more than 30μm, and the chip load was set at 0.15mm per tooth., the black regions indicating the conditions where chatter would occur. Gray regions indicate where the machining would be stable but the SLE specification would not be met. There are some regions where a larger axial DOC results in a better SLE than in regions with a smaller axial DOC. Relaxing the specification by allowing the SLE to be as large as 70μm results in the super diagram in which a substantially larger feasible machining zone is available. Similarly, reducing the chip load opens up more feasible machining zones until, with a chip load of 0.075mm per tooth and a permissible SLE of 70μm, all stable cuts satisfy the SLE condition.