A Bumotec s181 machining centre from Birmingham-based Starrag (www.starrag.com) is enabling a producer of ‘traditional’ turned parts to not only finish-machine a multi-operation component with interconnecting holes to a burr-free state (with high levels of roundness and surface finish), but is also allowing it to attract new business where effective and efficient single set-up multi-operation workpieces are required.

The Fanuc-controlled s181 turn-mill centre was installed to make a distributor for a respiratory protective device (the component that connects an oxygen bottle to a respirator mask, as used by the fire service).

Produced from a special aluminium alloy with silicon (AlSi05) forged blank, the workpiece presents a number of machining demands before it is anodised — in particular, the production of a hole (H7) that is drilled
to a tolerance of 14µm and must not have burrs on the interconnecting channels.

The Bumotec inserts the blank automatically and then processes all six sides of the workpiece.

One critical aspect of producing the distributor is the fact that the initial blank is forged to a high tolerance, so a specially designed clamping system — one that will hold the part rigidly, but without damage or deflection — has been developed and adapted to the machine.

The Bumotec s181 has an HSK-40 (30,000rev/min) spindle, but it can produce very small components (up to 32mm) to 1.5µm, and it is this quality that the new user says that “will position the company internationally for the production of high-precision components”.