Post Brexit, it is anticipated that a growing number of UK manufacturers will be cultivating an increasing amount of business from outside Europe.

One sub-contractor that already exportsa third of its output — nearly half of this to China, plus some to the USA and Canada — is Stroud-based Truturn Precision Engineering.

General manager Bob Wilkins says: “We turn-mill up to 80,000 flow-meter parts per month from a hard, exotic material for delivery to China. Customers there are very particular about the appearance of their components, as well as the dimensional accuracy, and they are constantly asking us to hold prices — or even reduce them.

“To help us meet these demands, we decided to end our policy of manually finishing every component. We now deburr, de-scratch and clean all the flow-meter parts in a vibratory bowl.”

As the turned parts are relatively small, the vibratory equipment chosen was a 21-litre bench-top TLV-75 bowl from Bletchley-based PDJ Vibro Ltd (www.pdjvibro.co.uk). This was purchased after successful trials at the supplier’s technical centre; the company also provided abrasive and polishing media, as well as two types of liquid metal-finishing compound.

The latter are added to the water in the bowl to degrease, inhibit oxidation and brighten ferrous and non-ferrous materials respectively.

Detailing the many advantages that the new finishing equipment brings, Simon Lane — Truturn’s quality, health, safety and environment manager — said: “Previously, one operator ran a cell of six sliding-head lathes and a second person deburred the output by hand.

“As manually finishing the components has been eliminated, the labour cost associated with running the cell has been halved. There has also been a saving in the metrology department, where the workload is lower following a move from 100% inspection to random sample inspection.”

Mr Lane also says that a reduction in rejected components has resulted in further cost savings. Rework and scrap, previously 2% of production costs, have been cut by 30% due to the higher consistency of vibratory finishing.

On the basis of this alone, the capital cost of the bowl was amortised within three months of installation, which was immediately after the MACH 2016 show in May, where the order was placed. Moreover, the machine was operational at the Stroud factory within half an hour of its arrival on site.

Component range

A significant proportion of the other components produced by Truturn is also finished in the vibratory bowl. Parts that are turn-milled on sliding-head lathes from stainless steel bar at a rate of 1,000 per month are processed, while the largest rotational part so far to be finished automatically was 100mm in diameter x 150mm long. Prismatic components produced on the subcontractor’s many machining centres are also deburred in the bowl.

Ryan Woodward, Truturn’s sliding-head-turning section leader said: “The PDJ Vibro machine is ideal for light- to medium-duty deburring and is often used to finish components completely, without manual intervention. However, if parts come off machines with heavy burrs, we knock these off quickly by hand — using a wire wheel — and then put the parts in the vibratory bowl.

“In such cases, the previous finishing time is reduced by typically 75%. Days and days of hand finishing time are being saved, rather than hours and minutes.”

The ISO 9001:2008-accredited sub-contractor, which is an NAMRC-approved F4N (fit for nuclear) company, is in the process of gaining ISO 14001 (environmental management) and BS OHSAS 18001 (occupational health and safety management) accreditations. It is also well on the way to a gold Investors in People award.

The company produces components and assemblies for the defence, oil and gas, marine, process and nuclear industries from a vast range of materials. These include Super Duplex, Duplex, Hastelloy, Inconel, stainless steels, mild steels, aluminium, brass, composites and plastics.

All can be processed in the vibratory bowl — and many already have been. Process times range from 1hr for a batch of tough metal components to 10min for plastic parts.

Media variety

There is considerable variety in the abrasive media used. For most deburring and surface treatment, two types of ceramic abrasive of different sizes are used; while plastic cones are used for lighter finishing.

In conclusion, Mr Wilkins said: “We are a medium-size company. We have 35 staff and achieved a turnover of £2.5 million in the last financial year. We have to look carefully at each item of capital expenditure; and even though the vibratory bowl represented a relatively small outlay, we were new to the technology and spent a lot of time researching the market, eventually shortlisting five potential suppliers.

“We chose PDJ Vibro partly because they were very helpful when advising us on the type of equipment and media we needed for our applications, and also because the company’s demonstrations were impressive and re-affirmed what we were looking for.

“We also appreciated their offer to take back the bench-top machine within six months — with no financial penalty — and upgrade it to a larger machine capable of accommodating larger production quantities and bigger components.”