Peak NC’s clients range from small, highly specialised precision engineering firms to household names in international aerospace production.  Projects we have worked on include:

  • Airbus A300 - A380
  • Boeing 737 & 747
  • Eurofighter Typhoon
  • Joint Strike Fighter
  • Astute Class submarine

The following case studies offer some typical examples of our work.

A380 Cover plates

Redesigned as part of a major weight saving program, the client needed to ensure a second supply source for the component in the event of machine breakdown.  To speed up production the surface finish needed to be of a very high standard to reduce polishing.

 

Despite technically being five-axis components, we programmed the series for production on a three-axis machine on which the client had available capacity.  The curved surfaces of the component were scanned to finish, exceeding the required surface tolerance criteria.

Titanium engine casing

The conical component is made from a solid titanium forging, and measures just under one metre across its base.  Weight is a critical factor of the components design, so the conical skin is exceptionally thin - in the order of 0.5mm in places.  All positional, section and surface finish tolerances are understandably very tight.

 

The geometry for the component is also complex – it is built up of a regular pattern of nearly 400 triangular ‘cells’ laid over the skin of the component, interrupted by various apertures and bosses.

 

Because the client was changing from chemical-etched to milled manufacturing, our advice was needed on design improvements for production.  Other design changes were also planned, due to the component’s R&D status.  A machine tool had been specifically purchased by the client for manufacture of this single component, therefore cycle times were also critical to achieve the required production schedules.

 

To help reduce the cost of redesigns, the programming of the ‘regular’ shaped cells was automated with a series of programming macros, which adapted to each new design with minimum intervention.

 

We also developed an innovative plunge roughing technique using a range of cutter sizes.  This eliminated more traditional roughing methods, saving considerable machining time.

 

The client is now able to reliably machine the component to the very high standard required and is comfortably meeting their production targets.

Lightweight tail section

The project consisted of two distinct groups of components; small parts measuring between 25mm and 400mm in length, and larger spars and frames, some measuring over 3m.  The client already had a five axis machining centre available on which to produce the smaller components but needed help specifying new machines for the larger parts.  With angled features nearing 50°, axis limits as well as spindle capacity and bed size were an important consideration.

 

One feature common to all the components was very thin and tightly toleranced wall sections, often less than 1mm thick.  On the larger components this carried a serious risk of distortion, while vibration was a concern on the free standing walls of the smaller components.

 

Cycle times and material usage were also critical to ensure the profitability of the project.

 

We helped the client select new five axis machine tools capable of producing the larger components, and wrote post processor configurations both for these new machines and the client’s existing machining centres.  We also contributed to the design of an interchangeable vacuum fixture purpose-made for the large parts.

 

A high speed machining technique of light, fast cuts achieved the tolerances required on all components, successfully avoiding distortion and vibration.  The resulting surface finish was of a very high standard, which combined with an innovative strapping technique greatly reduced the need for polishing.

 

The smaller components were nested, with up to 60 parts per billet, maximising material usage.  Cycle times were also considerably shorter than those forecast by the client.