Vargus Vardex thread turning tooling

Citation

(2006), "Vargus Vardex thread turning tooling", Aircraft Engineering and Aerospace Technology, Vol. 78 No. 4. https://doi.org/10.1108/aeat.2006.12778dab.005

Vargus Vardex thread turning tooling

Vargus Vardex thread turning tooling

Keywords: Aircraft components, Aerospace industry

In the highly-competitive world of sub- contract supply of precision machined components used in the aerospace and medical sectors, for example, Peter Day Precision Engineering constantly applies a policy of continual improvement throughout every aspect of the business – not least on the shopfloor where every avenue is investigated to machine more effectively and efficiently without sacrifice to workpiece quality (Plate 1).

Plate 1 Vargus Tooling's Vardex MiniL thread turning tool (Vargus/1/aeat/4/06)

The company's success at thwarting the threat of overseas competition, in particular, is based on a philosophy that hinges as much on the way in which every machine tool is used and every component produced as it does on the need for constant investment in the latest high-tech equipment as well as employee skills – including a progressive apprenticeship programme.

A current aerospace contract for large batches of 316 austenitic steel locking nuts also perfectly illustrates the significance of Managing Director Dave Causley's “we're always looking to improve” statement, since the combination of a Vargus Tooling Vardex MiniL thread turning tool and Vardex VHX inserts has cut thread generation cycle times from 8min to an amazing 3.5min, extended tool life and, because the job is completed in a single set-up, has also eliminated secondary machining.

“Supplying the parts in repeat batches of 1,000-1,500, we started by splitting the machining sequence to accommodate the requirement for a through-bore M12 thread, which was being generated by an internal screwcutting carbide tool,” reflects Dave Causley. “But we knew there was a better way, a way that would reduce cycle times and extend tool life, and therefore save money,” he says.

“We have a very good relationship with Trucut Tools, Vargus Tooling's local distributor – Trucut satisfies over 95 per cent of our tooling needs on a consignment basis – and because Trucut provides all-round engineering solutions rather than just tooling, we regularly get together and brainstorm applications.”

In the case of producing the thread within the locking nut, the result was the introduction of the MiniL threading tool with grade VHX TiN coated HSS inserts.” With reduced surface speed on the Citizen M32 sliding head auto (10 m min^-1 instead of 25 m min^-1 as required with carbide), the sequence of machining on the 13-axis machine with main and sub-spindle is now to turn OD, knurl, mill flats and cut out, centre drill and bore, chamfer lead for thread and turn down the face. The part is then picked up on the sub-spindle, rough and finish turned, and a groove is generated before reboring and thread turning.

“The Vargus Vardex tool has transformed a job that was once a headache,” exclaims Dave Causley. “In addition to at least halving cycle times and eliminating secondary/finish machining, because the tool is very stable – there's no chatter or noise – tool life is also so much better.”

“With such reliable tool life, we can confidently let the machine run unattended, including lights out, and an added bonus of the tool's insert bed design is that one cutting edge is always protected so compacted swarf is avoided, which wasn't the case previously.”

Designed for threading and grooving in bores as small as 3.2 mm diameter and up to 13 mm diameter, the Vardex Mini Pro range of indexable inserts comprises the Micro and Mini 3 (IC4), Mini L and Mini 3 (1 C 6) styles for pitches from 0.9 to 2 mm. The VHX insert style is complemented by VMX and VKP (TiN coated general use carbide), VBX (TiCN coated carbide for 1 C 4) ideal for steel, and VTX (TiAIN coated carbide for 1 C 4) for machining stainless steel.

Also available is the MilliPro range of solid carbide thread mills, for the creation of internal threads as small as M1.6 × 0.35. With three flutes each having three teeth, MilliPro is designed for the consistent production of thread depths up to three times diameter.

The success of this application has subsequently led to the use of the tool on other applications and other machines (Boley turning centres), with similar savings being generated.

It is clear that Peter Day Precision's continual improvement policy is certainly serving the company well. The 30-employee Christchuch (Dorset) operation currently occupies a total of 10,000 ft² across five buildings and boasts a predominantly UK customer base, most of which are first tier companies in the aerospace, medical, education and food processing sectors, and these are supplied on a kanban basis.

Dave Causley's right-first-time quality philosophy is underpinned by an impressive plant list – the CMC portfolio alone numbers 17 machines – and the operation is capable of accommodating shaft work up to 42 mm diameter and prismatic workpieces up to circa 800 mm × 500 mm × 500 mm.

This is complemented by accreditation to BS EN IOS 9001:000 and an impressive assembly operation that embraces PCB assembly, wired units and cable forms, for example, for single-source supply initiatives, especially for food industry customers. It is a policy that is helping the company continually go forward – for example, investment in a new site is planned – and it is enabling orders to be won back from overseas competitors.

Details available from: Vargus Tooling UK Ltd Tel: +44 (0) 1952 583 222; Fax: +44 (0)1952 583 383; web site: www.varqustooling.co.uk