Within just two months of changing its business from being a component orientated cell production operation to a ‘Group Technology and Skill Centre’ (GTSC) based on machine type, precision gear specialist FT Gearing Systems has been able to increase the collective output from its Citizen CNC sliding head turn mill centres by 20 per cent.
The immediate success of the ‘Citizen GTSC’ in FT Gearing’s newly acquired Unit 14 in Aldershot is a prime example of how a company can take stock and reconsider how the operational side of a business actually functions. After progressive growth from a two man operation set up by founder Des Fitzgerald in 1978, the company is now run by his two sons – managing director Graham and technical director Nigel – who have taken the business to a £7 million turnover, high technology specialist supplier of gears, miniature gearboxes and assemblies to the aerospace industry.
Said Graham Fitzgerald: “We felt we were efficient before as we were focused on how the parts were produced and set up a number of manufacturing cells where, for instance, we had a lathe, machining centre, broach and grinding machine all grouped together. We then had a setter/operator having total responsibility for all the different pieces of equipment.”
He explains how the operator went from machine to machine, which, on first appearance, gave good job satisfaction due to the different technologies involved, but Mr Fitzgerald is emphatic: “In the cold light of day, the operator became a ‘Jack of all trades’ but, in fact, through no fault of his own, rarely completely mastered one!” Worse still, he maintains: “When a part was not on the order schedule people had to be moved around the four units spread around the factory estate, it progressively became more difficult to control.”
Although FT Gearing has also applied the same GTSC strategy to fixed head mill-turning, its 4- and 5-axis vertical machining centres, gear cutting and grinding, the company uses the Citizen Machinery UK supplied machines (the carefully chosen partner for sub 32 mm diameter production) as a prime example, not only of the overall success generated by the GTSC venture, but also the unexpected benefits that have developed.
Mr Fitzgerald said: “We had eight machines from Citizen installed in three units that were spread up to 500 m apart around the estate. Now with another Citizen sliding head machine on order, this will be added to the Unit 14 installations and our team of nine engineers are ready to support it. Most important we are now benefiting from the creation a Citizen working team that is developing its interest in the business and adding a little competitiveness amongst themselves in what they are doing.”
He quickly pointed out that when unit 14 was taken over, the team we put together really saw it as their domain. They even chose to come in during the weekend and helped to remove an internal wall, selected the colours and painted the walls and sealed the floor prior to the installations.
The team collectively decided on the layout of each machine to suit their new roles and specified where the material, tool and spare parts stores were to be located and where the Citizen Wizard programming and inspection area would go. As a result, each one takes pride in keeping the machines and the machine shop spotlessly clean. He said: “They even approached and persuaded us to set up a mini training area where they can help each other to improve their sliding head skills.”
Mr Fitzgerald went on to describe how a level of comradery is helping to develop the skill sets as they bounce ideas between each other. He said: “We already benefit from the collective skills with someone always on hand with the knowledge to help, especially when someone is away.”
FT Gearing runs an overlapping double day shift from 4 am to 9 pm with the team working the inspection area between themselves. As a result of the changes, output from Unit 14 is now up by 20 per cent, exceeding over 7,000 parts a week. Batch sizes are between 200 and 2,000 in difficult to machine materials including a wide range of stainless steels, titanium, copper-based aluminium bronze and Maraging steel.
Maraging steel is a low carbon, high strength steel with between 15 and 25 per cent nickel content used in aircraft undercarriage and wing fittings. It is very unstable to machine because it has a natural tendency to creep so FT’s engineers have written a macro for the Citizen control system which is able to predict the size setting to use.
The company is a dedicated supplier to just eight OEM and Tier 1 aerospace customers for complex small assemblies and critical ‘Class 1’ components. These parts are all used in wing surface actuation and engine controls, instrument gearing, miniature gear heads, epicyclic fuel pump gears, drive shafts and thrust reversing gears.
The selection of Citizen Machinery UK as its key sliding head machine supply partner for turned parts up to up to 32 mm diameter over fixed-head machine configurations (these are housed in a separate unit for larger work and have also recently been configured into GTSC format) is one of ‘horses-for-courses’ according to Mr Fitzgerald: “The configuration of Citizen machines provide the ideal setting flexibility for us without going to very specialised and highly expensive turning machines. They are predictable and provide a totally consistent level of size, geometry and surface finish. In addition, Citizen Machinery UK provides a ‘genuine’ service and applications support when we need it.”
FT Gearing has two top-of-the-range 14-axis Citizen M32s, two B12s and one each L20E, A20 and a B16E. One of the latest Citizen L20E-IX is on order with Y-axis and 20 tool capacity and a short bar feed which has already had its position designated by the team in Unit 14. Said Mr Fitzgerald: “Our first Citizen installations of B12 and L20 machines have always been looked after and are approaching15 years old! They may not be as quick or flexible as the latest versions, but are still holding the level of tolerances we require on selected jobs.”
Due to the demands of the customer base, quality and consistency is a priority for the two directors Graham and Nigel. According to Nigel Fitzgerald: “Any lack of consistency in quality from the Citizen machines is never an issue. We are even able to maintain on certain components tolerances as tight as 5 microns. To help the production environment air conditioning is installed in several of the units including Unit 14. Within minutes of switching on a Citizen we have found the machine quickly stabilises and will hold size. It is rare to put in offsets except to account for tool wear on some of the difficult materials.”
Indeed, the Citizen B16E was producing spur gear blanks in a single cycle ready for gear cutting. All faces had to be perfectly flat and the OD held to 5 micron plus a process tolerance on the bore of 4 micron. A Citizen L20E, machining a S143 stainless steel shaft was also holding a 5 micron size tolerance which would normally be considered to be precision ground. At the other end of the spectrum, due to the unavailability of S28 material and FT Gearing having an oversize stock of bar, a Citizen M32 was engaged to reduce1 inch material to 3/16 inch for a 2,000 batch order. The machine was simultaneously twin-turning from the toolpost and turret with a combination of 12 mm and 5 mm cuts in a single stroke. The part was then finished machined on the M32 in the same cycle to create its other features, then shipped for heat treatment before a final grind.
FT Gearing is still family owned with father Des showing his interest with a visit at least one day a week. It now has 80 employees with sales of £7 million. The five separate units total 19,000 ft2 and the quality name plates, residing on the sides of its machine tools testify to the level of machinery and technology installed which has absorbed investments of over £4 million in the last four years.