Breaking new ground

Castle Precision manufactures a wide range of parts including fan discs, blades and rotors for aerospace applications in materials such as steel, titanium, udimet and nimonic. It has almost 60 years of experience and an extensive portfolio of quality approvals – including being the first subcontract company to achieve a bronze SC21 award in Scotland. Castle is an EMTA approved training centre for modern apprenticeships up to level 3 SNVQ, HNC and HND and is also an approved SNVQ assessment centre.

The production of tubular parts, which required both internal and external grinding, drove the company's investment in the Taiyo Koki NVG-8T. Chairman and managing director, Marcus Tiefenbrun, says: “The benefit of the Taiyo Koki is that the part is held vertically, enabling us to completely grind the inside and outside diameters in one operation without resetting. A horizontal grinder would make it necessary for us to reset the part between the inside and outside – a task which is difficult to do with complete accuracy. With the Taiyo Koki we can guarantee wall thicknesses and concentricity and avoid problems such as taper or ovality.”

Taiyo Koki is part of the Mori Seiki Group of companies and temperature controlled and sealed environments for manufacture, and specially developed testing routines for each machine, ensure accuracy and reliability. Mr Tiefenbrun adds: “The machines are beautifully made and extraordinarily accurate. They are used by all the leading machine tool builders in Japan and widely used in aerospace and automotive manufacture.”

The machine includes a number of features which claim to enhance production and simplify manufacturing. “The machine's ATC makes six wheels available to us, so that we can completely grind the job in one setting,” Mr Tiefenbrun explains. “The only exception is if the part needs to go for treatment or if there is an inaccessible shoulder. The system on the machine automatically finds and updates the datum, and wear control dresses 10µm off the wheel at each pass.

“Macro programs determine the number and type of cuts necessary for each operation and the machine's gap eliminator detects when the gap between the wheel and workpiece is less than about 400μm, automatically cutting the feedrate, which is a great timesaver.”

As Mr Tiefenbrun reveals, accuracy is important to Castle Precision with the company often working to micron tolerances with excellent surface finishes and material grain structures. “The Taiyo Koki enables us to make good parts, up to 1m high, faster. We can manufacture larger components with vertical grinding as there is no need to hold parts up to the wheel – a necessary requirement with horizontal grinding.”
As well as the Taiyo Koki NVG-8T, Castle Precision has over 40 Mori Seiki machines, including six Mori Seiki SL75 lathes, five SL603B lathes, two NMV5000 5-axis machining centres, a NT5400 DCG multi-tasking machine and an NT6600 DCG multi-tasking machine.

Mr Tiefenbrun concludes: “We have an excellent relationship with Mori Seiki and Dr Mori himself. We are demanding customers and collaborate closely with the company. Vertical grinding technology is relatively new to us and Mori Seiki has been instrumental in helping us meet our manufacturing objectives, not only through its products but also its technical support, service levels and expertise.”

Mori Seiki
www.moriseiki.co.uk