To help meet growing demands for torque control tooling, MHH invested in two Citizen sliding head lathes from NC Engineering, and is now achieving an average 65 per cent higher productivity. The installations have eliminated five previous machines, cut some cycle times from nine minutes to just 80 secs and significantly reduced work in progress! MHH Engineering's capability to produce torque control tooling has elevated its Torqueleader product range to a market leading position. The roll-on effect of its global success is that the company's order book has risen to such a level that, until recently, meeting its own stringent delivery promises was becoming a problem.

With high growth, the company had to change its production methods to keep up with demand.

MHH's production director, Joe Ellera, said: 'When we started looking for new turning machines, we closely examined the technical specifications based around our components.

We were very keen to maximise production efficiency, in terms of machining as quickly as possible to gain the highest productivity but also to reduce lead times, machine a finished component in one set up and maximise quality at the turned stage.

'We previously had a range of six semi-automatic lathes which were at the end of their useful lives.

Labour costs and maintenance were very high and their capability limited.

We needed to combine mill-turning and reduce operations, work in progress, lead times and costs.' Given the components that were planned to load onto the new lathes, MHH Engineering carried out a detailed analysis of the market and the Citizen L32, was first seen by the company at MACH 98 and found it an ideal specification.

Maintains Joe Ellera: 'Although sliding head turning was new to us at the time it provided the obvious solution.

In addition, the Citizen was a very compact machine requiring only 1,100 mm by 2,520 mm, plus the bar feed.' Besides the increase in turning productivity, the 5,000 revs/min driven tooling on the Citizen means that milling, drilling and the machining of the component front and back end can be accomplished in one setting.

The L32 is able to carry five turning and four driven tools on its vertical tool slide, three tools located adjacent to the pick-off subspindle for front machining and five stations for back machining.

'With a 5.5 kW, 8,000 revs/min main spindle and 2.2 kW, 6,000 revs/min secondary spindle and 32 mm bar diameter (by 250 mm turning length), our five-axis L32 provides us with all the functionality we need,' confirms Joe Ellera.

'In our view, for turning, drilling and milling with the C-axis spindle, there was really nothing else in the turning market place to compete with it.' He goes on: 'It is very difficult to perform a straight comparison of cycle times with the previous method of manufacture, because the Citizen can do so much more work.

However, we measure productivity and have found that we are around 65 per cent better off on each component.' The results of this initial investment in sliding head technology proved so beneficial to the company that, in October 1999, it purchased another Citizen L32 Type VII.

Chris Wood, machine shop manager, takes up the story: 'We had established what the Citizen lathe was capable of, but still had a massive problem completing orders with a backlog of parts.

So we purchased a second lathe, with an almost identical specification.

'Five machines were replaced by the two Citizen lathes, performing 'one-hit' cycles.

On some components we have cut cycle times from 9 minutes down to 1 minute 20 seconds.

One of the existing lathes has been kept for deep hole drilling a torque wrench handle.' Most of the programming is performed at the machine, and MHH Engineering has built up a small library of components with around 30 repeat parts programmed into the control.

An important feature of the control is the 'Program Check' function which allows the program to be run forwards and backwards at a slow feed rate allowing optimisation of the different functions.

'The volumes do not fluctuate like they can with subcontract work.

We can also process specials in the normal production run, with like programs easily being edited to run with existing tooling,' Joe Ellera explains.

Having operated an MRP system for the past 12 years, the company is adept at improving the flow of work through its whole operation.

The aim for the parts loaded on the Citizens is to try to produce batches within product families, to minimise set-up times.

Batch sizes have recently been increased to a minimum of 1,000, with the intention of only carrying out one set-up per shift.

'However, re-setting is so quick we can change over in two hours.' Joe Ellera maintains: 'Both machines run for a minimum of 80 hours per week and, with overtime, actually around 90 to 100 hours per week.

We mainly cut steel, but also accommodate brass and aluminium components.' LNS bar feeds were supplied as part of the machine package and these allow 17 bars to be loaded so one operator can look after two machines each shift.

Further benefits realised from the company's investment include a reduction in the inventory on the shopfloor.

'We wanted new machines to be able to complete components in one setting.

By completing all of the turning, milling and drilling in the same cycle, this is what the Citizens are providing for us.

They are doing exactly what we expected,' concludes Joe Ellera.

Located on its own six and a half acre site at Bramley, near Guildford, Surrey, MHH Engineering has followed a steady and sustainable growth of its business.

All of the company's torque control products are designed and manufactured in-house, and the company is accredited to BS EN ISO 9002 and is a UKAS accredited calibration laboratory.

Although established over 60 years ago, the company has specialised in tooling for torque control for around 40 years.

Three partners originally set up the firm and the early years were focused on subcontracting and general engineering.

Success came with the design of its first manual torque wrench, and from that point, the company evolved towards the eminent position it holds today.

Until recently, MHH Engineering was a member of the Bullough group of companies.

In December 1999, following a share capital purchase, the company became part of the German Gedore group, to which it had supplied branded products for many years.

Joe Ellera, says: 'The partnership with Gedore is ideal for us.

Our previous group owners were very diversified and now, as part of a larger family of hand tool manufacturers, the business is more focused.' The 80-strong MHH Engineering has a turnover of GBP5.5.

million and exports 70 per cent of production.

Its tools are supplied as a premium brand to a wide spectrum of industries around the world, including many house-hold names.

Maintains Joe Ellera: 'With increasing emphasis on quality, the demand for a tool that is capable of eliminating operator error - such as the torque wrench - constantly increases the market for our products.' The majority of the company's products are manual torque control wrenches and screwdrivers, which fall into two categories.

Tools that can measure the torque being applied and tools that are preset to apply a level of torque.

Many of the designs are well established, and product life cycle tends to be very long.