Competitive edge

Increasing the capacity and capability of the machine shop with two new Hardinge Bridgeport machining centres will ensure leading vintage and historic car replica and restoration specialist Tom Dark Engineering maintains its pole position in this highly competitive field.

The two machines were supplied by the Engineering Technology Group (ETG) and have fitted seamlessly into Tom Dark's manufacturing operations with seven specialist engineers operating 12 hours a day.

Tom Dark Engineering is one of the UK's leading exponents of vintage race and touring car engineering, being able to manufacture and supply a single component for a rare historic vehicle to a complete marque replica, capable of full race competition.

“Some of the replica's we create are of high value, legendary cars from the likes of Maserati, Bugatti and MG,” founder and managing director Tom Dark explains. “Our reputation has been built on being able to recreate anything from an obsolete suspension component to a complete competition or road ready car and to do that we have to have the manufacturing support infrastructure. As such we have invested in the appropriate machine tools to enable us to be as self-sufficient as possible.”

Tom Dark's machine shop and assembly plant is located in a converted, custom designed barn near Kiddington, Oxfordshire in the heartland of the UK's motorsport industry. Very often the company is tasked with manufacturing components without any drawings – a process that involves creating a toolroom copy, extensive pattern work for castings and use of 3D and solid modelling.

Raw materials are also wide and varied: bronze, aluminium and cast iron are commonplace but EN24 and EN36 alloys are used for high tolerance stress components.

“We have a mixed workshop capability but were very careful when we specified the two Hardinge machines to ensure they gave us the optimum capacity when we need it coupled with the precision, capability and reliability essential in the business,” Mr Dark explains.

Most recently, Tom Dark has acquired a new Bridgeport XR 760 high performance VMC and a large capacity Bridgeport GX 1600 VMC, both of which provide the scope to machine large components such as a complete cylinder block casting to the plethora of small components that make up a car or sub-assembly.

The XR 760 is equipped with a Heidenhain iTNC530 control and operates at a maximum spindle speed of 12,000rpm. It features a 30 tool magazine capacity and as with all Bridgeport machines, is equipped as standard with a Weiss spindle, Big-Plus dual contact toolholding capability and offers the user optimum rigidity and thermal stability. The machine supplied to Tom Dark was pre-wired for probing and a fourth axis pre-wire for when Nikken fourth axis capability is required.

The GX 1600 VMC is currently the largest capacity Hardinge VMC and was specified mindful that the company needs the facility to machine complete engine castings, which are sometimes 1.4m in length. Also equipped with a Heidenhain iTNC530 control, it has a 30 tool BT40 carousel, 10,000rpm spindle and the fourth axis interface.

Aware of the need to machine cylinder blocks and similar large components Tom Dark also specified a 260mm Z-axis riser block on this machine to optimise the height within the machining cell.

“An in-house cylinder block machining capability is important to us because we also machine the pistons and the cam shafts as well, giving us complete process control,” Mr Dark reveals. “In the past though we have machined blocks from billets not castings – a Bugatti Type 50B engine comes to mind – and that whole project probably entailed some 6,000 hours of machining and building.

“The Bridgeport machines are undoubtedly the cornerstone of our manufacturing operations,” he concludes. “Previously we have operated a range of Bridgeports – VMC 800, 600XP, 1000XP – so we're longstanding users and they have held us in good stead.”
Tom Dark Engineering
www.tdengineering.co.uk

ETG
www.engtechgroup.com