On track for expansion

The business has grown over 36 years from the racetrack involvement of the Munday family, led by father Vincent. It is now run on a day-today business by his two sons Dan and Chris.

Production at the Market Overton factory in Rutland is steeped in CNC machining centres and fixed head lathes for turning, for which around £1 million has been invested over the last five years. However, around the family table, discussions began about the company investing in CNC sliding head turn-mill technology for producing smaller precision parts.

Sales director Dan Munday comments: “We used MACH 2016 as the final decider and ordered the Citizen Cincom L32-VIII with removable guide bush which was installed in July. Almost immediately we wondered why we had debated so long. Such has been the success of the machine already, that we are now planning for a second because we are becoming concerned we could run out of capacity.”

Since July, apart from more effectively switching work from other machines, the firm has won new contracts that it could never have dreamed of producing before. The directors have already noted how the company has increased not only profitability, but also throughput, with cycles now being clocked two-thirds faster than before. For example, one part taking 50 plus seconds on a fixed head machine is now produced in just 17 seconds.

However, most important to JC Precision is that lead-times are being slashed against previous methods, which involved separate fixed head turning and often further milling and drilling set ups as well as manual finishing. Further benefits are also being found from the ability to achieve total consistency enabling through-the-night running and the ability to maintain tolerances as tight as 10µm when needed.

As a result, previous production methods involving four or five set-ups have been reduced to one including in-cycle deburring. Batches as small as 20 have proven to be economical, especially when planned with other work with the machine already either set with or without the guide bush in place or having no need for a bar change. This economic capability for small quantities has also encouraged design input for certain key customers as well as development and providing a prototype service.

In ordering the Cincom L32-VIII the Mundays elected to specify the detachable guide bush. “We have considerable demands for special sizes of short length parts such as spacers and even washers where we can save on bar end material and it takes less than 30 minutes to change over to a guide bush when needed,” Mr Munday says.

One of the concerns holding back the venture into CNC sliding head technology was the different approach to the application when compared with more traditional CNC turning.

“We had excellent support from Citizen which quickly convinced us how our worries were totally unfounded. What makes things easier is the Cincom control software plus Citizen’s AlKart CNC Wizard programming aid which certainly helped us to get up to speed very quickly.”

Mr Munday describes how the company is running a wide range of parts in materials including EN24, 316 stainless steel, plastics, aluminium and brass on the machine tool. These include special bolts and pins, master cylinder brake pistons, brass fuel fittings and stub axles. Indeed, a further point of doubt in the capability of sliding head machining has also been dispelled in producing a stub axle from 31mm diameter EN8 when in a single cut of 7mm. The part was taken down to 17mm diameter and held to a 0.025mm tolerance. The part was then threaded each end from the main and sub-spindle and within the cycle, a hexagon was milled adjacent to a flange.

JC Precision, which employs 15 people, is currently planning to add another building at its site. This will enable it to meet future demands and to install a second Citizen machine helping to increase turnover from the current £1 million from the karting sector as well as its more general subcontract business.

As father, Vince Munday asserts: “The whole business has always maintained its steady growth with its input into design, development and prototype activities. Although this takes up valuable production time, it is paying massive dividends in customer loyalty and a longer-term order book.”

The Cincom L32-VIII has five axes with a 40-tool capacity of which 15 can be driven. It has a 7.5kW main and 3.7kW sub-spindle each having a maximum speed of 8,000rpm. Driven tools are powered by a 1kW, 6,000rpm motor. Of major importance, and proving to be a key factor in the firm’s applications, is the ease of removal or replacement of the guide bush assembly from the main spindle to accommodate the machining of greater numbers of shorter parts from a bar.

JC PRECISION ENGINEERING www.jcengineering.co.uk

CITIZEN www.citizenmachinery.co.uk