The 8” chuck, Fanuc-controlled SMX 2100S featuring two, left and right, opposing 22kw/5,000rpm spindles, a 12,000rpm B-axis milling head, a 40-tool position ATC, integrated thermal compensation and a 12/24-position lower turret is a high-performance machine capable of producing complex, high-precision parts in one hit.
The machine was selected, by Mills CNC, to appear at Seco’s Inspiration through Innovation event to demonstrate the inherent flexibility of an advanced DN Solutions’ mill-turn machine, and the significant productivity and process efficiency gains it provides to aerospace component manufacturers.
Once the machine was decided upon, engineers from Mills CNC and Seco Tools, along with input and assistance from Hainbuch (work-holding) and Open Mind (CAD/CAM software), worked in close collaboration to design and develop a secure and reliable process to machine a complex, high-precision aerospace part at the event.
The part selected for the live machining demonstration is an aerospace impeller which features an axial hub with numerous overlapping and twisted blades and splitters attached to it. The impeller being machined on the SMX 2100S at the event is made from an EN 8 carbon steel billet and part dimensions are, approximately, 165mm (long) and 220mm (diameter).
In addition to its non-developable blades which can only be produced, effectively and efficiently, through simultaneous 5-axis machining, other processing difficulties include:
- Because the space between adjacent blades is small, with channels becoming narrower as the radius decreases, issues concerning tool reach and potential collisions and interference between tools and blades exist.
- As the blades and splitters are thin and are relatively delicate thermal deformation, occurring during machining operations, can affect part quality, cycle times and tool life.
The machining of the impeller involves a number of different machining operations.
To machine the front end of the part on the SMX 2100S’ left spindle, a 3-Jaw chuck is used with specific operations including 3-axis turning, skiving, boring and finish turning.
To process the back end of the impeller, completed on the machine’s right spindle using a mandrel, operations include simultaneous 5-axis machining, turning and drilling.
Tool selection is clearly important and numerous tools (i.e., tapered tools, barrel tools, blanking tools etc.), are required to achieve the desired roughing, semi-finishing and finishing results.
At the live machining demonstration, Mills CNC pre-sales engineers will be available to explain the machining process i.e., how and why it was created, its constituent elements and the challenges involved, in more detail.
