All-electric tube bender adds shape-forming capabilities

Madera, California – The European aerospace tubular parts manufacturer SL Engineering is continuing its investment in advanced automation with the acquisition of a second all-electric CNC tube bending machine from Unison.

 

The new machine enhances SL Engineering's manufacturing capabilities, especially its ability to produce more complex tubular shapes. It also extends the size range of tubing that can be bent using all-electric servomotor-controlled movement – to tube and pipe diameters up to 80mm. 

 

"Engine and aircraft manufacturers are taking advantage of the advanced shape forming capability of state-of-the-art tube bending machines by specifying more complex shapes and highly challenging tighter-radius bends – to save weight and space and eliminate welded joints," says Shaun Stevenson of SL Engineering. "The sophisticated bending capability of Unison machines, which allow greater control over tube clamp and carriage push forces, helps us to achieve these new levels of precision. If we did the same jobs on our old hydraulic machines we would be much more reliant on highly skilled operators to both set up the machines, and make the parts with additional weld joints, and hence additional cost."

 

SL Engineering (SLE) is a Tier 1 supplier of rigid tube assemblies and precision machined parts for aerospace applications, and supplies components to major engine and airframe programs from commercial aircraft to military programs such as the Joint Strike Fighter (JSF). 

 

SLE's business today is characterized by a need for manufacturing flexibility. The average batch is around 5 to 25 parts, and orders can even be for just a single emergency aircraft-on-ground part. Demand for greater precision and shape complexity is another major facet of its work. Until recently, few tubular parts required bends with radii of less than 2D (twice the tube diameter). Today, however SLE regularly receives requests for bends of 1D, and for shapes with minimal straight sections between bends. The use of thinner walled tubing, and expensive specialist materials such as titanium and Inconel are further trends.

 

These demands are behind the company's moves to all-electric tube bending technology. SLE installed its first such bending machine in 2010 – a 30mm diameter Breeze from the UK manufacturer Unison. Much of SLE's work is on diameters of 30mm or less, and most of its current work falls into the sub-50.8mm range. The first all-electric machine has proved critical for SLE, allowing it to handle small batch setups much more efficiently and quickly – with zero or minimal scrap. As a result, the company channels most new work for smaller parts onto the 30mm all-electric machine, and transfers many older parts onto the machine by creating new bending programs as orders come in. After almost four years of operation, the 30mm machine now produces a significant proportion of SLE's business. SLE typically has anywhere from 500 to 1,000 live jobs at any one time.

 

The latest machine that SLE has acquired, a Unison Breeze 80, now gives the company all-electric CNC tube bending options for tube diameters up to 80mm. The machine also incorporates a multistack/multiradius tooling capability. This feature is a critical aspect of achieving some of the complex tubular part shapes and multiple bend sequences that are being specified on today's aerospace programs.

 

"We continue to see many challenging opportunities in the sector, but it does require significant capital investment," adds Stevenson. "The new Unison bender, along with further investments in 5-axis machining, has helped SLE take its manufacturing capability to a new level. We can meet the most complex tube assembly specifications that aerospace companies require today, and the combination of advanced machinery and our know-how gives us a platform to raise the bar even higher, and differentiate SLE from our competitors. Another service we offer to clients who are able to provide us with pre-release drawings, is evaluating manufacturability and advising on the potential for manufacturing and cost saving improvements before final drawing release."

 

Tubes are often the last parts to be defined and designed – whether they are for an engine or airframe. Using its own customized macro-driven CATIA V5 closed-loop CAD/CAM facility, and Unison's three-dimensional simulator, SLE can create new CNC bending programs for the Unison machine very rapidly –  providing support for clients that are unable to supply tube/pipe details until the very late stages of projects.

 

"All-electric tube bending technology has given this client both a rapid return on investment, and a means of tackling emerging challenges such as bending exotic materials," adds Steve Haddrell of Unison. 

 

Unison tube bending machines are sold and supported in North America by Horn Machine Tools. 

 

Source: Unison Ltd.