In-cycle spline milling of the drive shaft using a Horn cutter

Tooling manufacturer Horn, which is represented in the UK by Ringwood-based Horn Cutting Tools, is saving costs for a customer by not only turning a drive shaft on a multi-tasking CNC lathe but also milling a spline in the same set-up, an operation that was previously sub-contracted out.

The shaft, which is 200mm in diameter, almost 5,000mm long and weighs around 600kg, is used in the construction of large engines. Horn suggested that the spline teeth be machined using its 635 milling system. The special profile of the tool’s six teeth matches the nominal profile of the tooth flanks on the workpiece.

The overhang of the tool is relatively long due to the cutting conditions but the solid carbide, vibration-damped shank minimises vibration. All Horn tools for circular milling have an internal coolant supply. The precise interface between shank and insert allows micron-accuracy concentricity and run-out of the insert during changeover. Roughing and finishing are done with the same tool. Production is now faster and the quality of the splines is significantly improved.