Product Details Supplier Info More products

The Citizen A32 CNC sliding-head turn mill has increased productivity at Labfacility of Bognor Regis, a large manufacturer of temperature sensors.

Tony Russell, general manager of the Connector Division, said: ‘The Citizen A32 installation in November 2008 provided us with a much needed increase in turn-mill capacity (from 16mm bar) to 32mm.

‘Also, due to its inherent rigidity coupled with its rapid control processing speed, 45m/min traverse rate and overlapping tool slide capability, the machine has cut existing cycle times by at least 30 per cent,’ he added.

Labfacility is recognising a growth rate of around 10 per cent and exports have grown by 20 per cent over recent years for its range of sensors and connectors that includes standard and miniature, plugs and sockets, some able to withstand temperatures up to 560C.

It also produces thermocouples, infrared sensors, thermometers, temperature measurement devices and process control and transmitting devices, and also has a calibration facility for temperature probes between -10C to 1,200C.

Originally set up to provide a precision turned parts service for its own OEM component production with a capacity up to 42mm diameter bar size, the service was expanded into subcontract supply.

This now contributes sales of 25 per cent to the business turnover.

‘The need for temperature and process control has never been greater because the monitoring of any change is so important today over a multitude of sectors and applications from food and drink, refrigerated vehicles, aerospace, automotive, petrochemical and electronics to medical and plastics industry,’ said Russell.

For the company, in-house production is critical due to the specialist involvement required and need to control production of so many different and unusual types of materials – that can also be difficult to source and tend to be very expensive.

‘This means our selection of production equipment and in-house skill levels are vital to our existence,’ said Russell.

‘Our capability has also been drawn to the attention of other companies that are seeking a reliable and experienced turned parts supplier and led to this side of the business growing quite quickly,’ he added.

In his view, this puts his Citizen machines well into the context.

A K-16 sliding head installed in 2006 allowed the company to combine operations into a single cycle – something that could never be achieved with two-axis lathes.

The K-16 also freed up design restraints for more complex components and enabled previous subcontracted parts to be brought back inside.

‘We made an immediate 25 per cent saving with that machine, and the Citizen A-32 gives us an even greater contribution to our productivity,’ said Russell.

The installation of the Citizen A32 has recorded 18-hour day production runs through the single-shift operation.

According to Russell’s records, it is also achieving a utilisation level that is exceeding 55 per cent and still growing, a great achievement for small batch work.

The K-16 is running at 75 per cent, which tends to be on longer running jobs with fewer changeovers.

Helping improve the result of greater frequency for changeover and tool change is its use of the Sandvik QC quick-change tool system on the Citizen A32, which allows the setter to change all six turning tools in less than 10 minutes.

To Labfacility this is important as thermocouple materials are so demanding to machine especially when nickel chrome, nickel aluminium and cupro-nickel alloys are involved.

These are in addition to a wide array of stainless materials such as 431 magnetic iron and the normal copper, brass and steels.

Due to the expectation of swarf problems from these materials, Russell’s machine specification for the A32 included Citizen’s 2,000psi Coolblaster II and from experiences gained, this programmable high-pressure coolant system is to be retro fitted to the K-16 as well.

‘Coolblaster gives so much added security to the turning process, helping to avoid “birds nesting” of swarf that would be so troublesome when running unmanned with these difficult materials,’ said Russell.

He also cites its advantage when drilling deep holes; the system has the pressure to evacuate swarf chips without pecking cycles and the ability to keep coolant at the cutting edge of the tools.

Coolblaster also ensures the collet on the subspindle is regularly flushed and is free from contamination ensuring a true pick-up of parts for finish machining once they are exchanged from the main spindle.

Parts produced include compression fittings, glands and plain and threaded pot seals between 0.5mm and 6mm diameter, probe tips, terminal head fittings, connector pins, bayonet caps and adaptors, caps and adaptors and locknuts, which currently total some 300,000 parts a year.

Batches tend to be between 1,000 and 5,000 parts.

However, a connector pin can be required in batches up to 10,000 in difficult materials, and these are mainly run on the K-16 at a frequency of every three weeks or so.

To simplify changeovers, Labfacility is able to group together some of the 13 different product types produced for its own use into standard material sizes of 8mm, 13mm and 16mm.

One important saving on material has proven to be very welcome by the production team through the turn-mill capability of Citizen machines and particularly the extra torque given by the A32.

This has produced savings of up to 40 per cent against the price of each metre length of some of the more difficult materials by milling hexagons on the machine rather than having all the problems associated with bought-in hexagon material.

‘Setting and machining can be faster, tooling lasts longer and a milled hexagon really looks a precision part, and this round material is easier to obtain and stock,’ said Russell.

Citizen Machinery

Citizen is the world leader in CNC sliding head ‘one-hit’ turn-milling technology. It has a range of machines having a maximum bar capacity between 4 mm on the compact micro-machining capable Citizen R04 to 32 mm on the top of the range Citizen M32-VII which has the added capability of two Y-axis cross-feeds.   

The M32 can carry up to 80 tools, of which 20 can be driven, and can cut with three tools simultaneously giving low cycle times and high levels of productivity.  Also, fully automated unmanned cycles can be utilised through an integrated gantry option and conveyor system that helps ensure damage free parts during uninterrupted batch production.  A high pressure 2,000 psi CoolBlaster coolant system is a further option to optimise swarf control, tool life and machining difficult materials.

Following the acquisition in Japan in 2008 of 65 per cent shares in Miyano, the fixed head turning centre specialist, the two companies are maintaining their separate high profile brand names utilising a single sales operation.  However, turn-milling solutions from bar up to 64 mm diameter can now be provided.  In addition, with the Miyano range of turning and turn-milling machines for chucking operations, cell-type applications can now be accommodated with a wide range of automation options.   

View full profile