First aid for cutting processes

What makes the Bumotec s181 stand out so much that Berlin- based turned parts contractor Heinrich chose it when they began cutting critical components, with the level of quality being essential to the safety of emergency service personnel? Bassem Sudki, Project Engineer at Starrag Vuadens SA, Vuadens (Switzerland) has been delivering a very specific kind of first aid.

Mr. Sudki, in general, what is special about the Bumotec s181 – which parts is it best suited for machining?

Sudki: The Bumotec s181 can be used for machining complex components made from bar stock with a diameter of up to 32 mm. The machine features a mineral casting bed, the latest CNC technology and linear motor drives to guarantee uncompromising thermal stability and performance. The s181 is especially well suited to the production of watch components, surgical instruments, medical implants and complex micro-mechanics.

Interview with Bassem Sudki, Project Engineer at Starrag Vuadens SA, Vuadens (Switzerland)

“The s181 is especially well suited to the production of watch components, surgical instruments, medical implants and complex micro-mechanics.”

What were the key considerations when the machine was used to produce the first component, given that this item was the centrepiece that connects an oxygen tank to a respirator mask?

Sudki: The initial material is a forging blank made from a special aluminium alloy that contains silicon. Due to its shape, size and the type of machining, this forging blank cannot be fed conventionally to the main spindle. For this reason, we recommended that the customer used a palletising system with ten pallets that would allow a total of 300 parts to be stored. After loading, the machine automatically feeds the unmachined parts to the main station. The palletising system transports a pallet into the machining area. The unmachined part is moved from the pallet into the clamping system of the main spindle by a specialised gripping tool in the milling spindle. This gripping tool is operated in the same way as a standard milling tool: It is actuated pneumatically and loaded as a milling tool in the tool magazine.

No doubt the clamping system plays an important role in relation to the shape of the respiratory protection component.

Sudki: Yes. We have developed and introduced a specific pneumatic clamping system for this component and this machine. The system simultaneously fulfils several functions: It clamps the component during machining whilst also providing enough space for the cutting tools. The pneumatic gripper also enables automatic yet precise feeding of the unmachined parts, as well as safe access to the re-clamping system. The process of transferring the components from machining station 1 to machining station 2 also runs automatically.

What happens when other components need to be machined on this machine? What does the operator need to modify on the clamping system?

Sudki: In this case, the operator uses some specially shaped clamping plates, which offer great flexibility. Thanks to this design concept, there is no need to modify the clamping system completely when the unmachined part or the machining process changes. The customer need only change the clamping plates.  

How does component handling function?

Sudki: After machining, the finished part is automatically deposited into a movable drawer. The drawer is transported out of the machine to a collection container via a conveyor belt.

When working with aluminium, the machining process creates a lot of swarf that combines with the cool- ant to form a sticky mass: How does Starrag deliver a reliable, efficient and environmentally sensitive cutting process?

Sudki: Two cutting tools working simultaneously lead to high material removal rate. Therefore we recommended that the customer used a compact complete solution directly at the machine featuring integrated filtering, cooling, pumping, pressure generation and swarf conveying processes that would also deal with treatment of the coolant. In conjunction with the directly coupled swarf conveyor, this system facilitates an autonomous, closed process.