Subcontract machinist JC Precision Engineering, has more than one string to its bow, as it earns 70% of its turnover from producing a wide range of components for racing go-carts.
This business has grown progressively from the race track participation of the Munday family led by father Vincent who set up the firm 36 years ago and is now run on a day-by-day basis 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, usually buying one machine a year.
The family had long considered investing in CNC sliding head turn-mill technology for producing smaller precision parts, and following a visit to MACH 2016 decided to order a Citizen Cincom L32-VIII with removable guide bush.
This was installed last July and the company is already considering a second machine as it is concerned it will run out of capacity.
Since July, apart from more effectively switching work from other machines, the firm has won new contracts that they could never have dreamed of producing before. The directors have already noted how they have 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 secs.
However, most important to them is that lead times are being slashed compared to previous methods which involved separate fixed head turning and often further milling and drilling set ups as well as manual finishing. Indeed, further benefits are also being accrued from the ability to achieve total consistency enabling ‘through-the-night’ running and the ability to maintain tolerances as tight as 10 micron 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 Munday’s elected to specify the detachable guide bush. Said Dan Munday: “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.”
He describes how they are running a wide range of parts in materials including EN24, 316 stainless steel, plastics, aluminium and brass. These include special bolts and pins, master cylinder brake pistons, brass fuel fittings and stub axles. Indeed, a further point of disbelief in the capability of sliding head machining has also been dispelled in producing the stub axle out of 31 mm diameter EN8 when in a single cut of 7 mm, the part was taken down to 17 mm diameter and held to a 0.025 mm 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 Engineering, which employs 15 people, acquired its premises in 2000 having a floor area of 1,000 m2 and is currently planning to add another building on the site. This will enable them to meet future demands and to install a second Citizen helping to increase turnover from the current £1 million from the karting sector as well as its more general subcontract business.