Live-Tooling

Swiss-type lathes are designed for machining small, slender parts. With live tooling and through-coolant capability, they can handle gun drilling for short deep holes. I have been running gun drilling operations on Swiss lathes for about four years, primarily for medical and precision instrument components. The approach is different from a dedicated gun drilling machine, but with the right setup it produces acceptable results for the right applications. Capabilities and Limitations A Swiss lathe is suitable for gun drilling diameters under 6 mm through lengths up to about 10:1 L/D ratio. Beyond that ratio, the coolant pressure and chip evacuation limitations become too severe. The main limitation is coolant pressure — most Swiss lathes have 200-500 psi coolant systems, while dedicated gun drilling machines run at 1000-3000 psi. ...

When a CNC Lathe Makes Sense for Gun Drilling A dedicated gun drilling machine is the right tool for production deep hole work. But I have run plenty of successful gun drilling jobs on standard CNC lathes when the volume did not justify a dedicated machine. The key is knowing the limits. In my experience, a lathe with live tooling and through-coolant capability can handle L/D ratios up to about 10:1 reliably. Beyond that ratio, the alignment challenges and coolant pressure limitations make a dedicated machine necessary. ...