By installing a bar fed CNC lathe, British Micanizing is able to produce complex electrical insulation components out of nylon, polyethylene, polypropylene and all plastics laminates grades.

Prior to installing a bar fed Colchester Tornado A90 CNC lathe, British Micanizing, a specialist in the production of electrical insulation components out of Nylon, Polyethylene, polypropylene and all grades of plastic laminates, was having to walk away from potential business involving more complex machining because its methods were not viable. Based in Great Barr, Birmingham, the company, which has been a niche player in electrical insulation components, had not suffered using its conventional machine tools and indeed, with a manufacturing history dating back to 1917 it was well-established in its business. However, as manufacturing director Alan Godwin explains: 'We were seeing more and more lost opportunities and a new contract for insulation bushes for the Ministry of Defence brought forward a decision to invest in CNC.' The directors decided they wanted a British built machine and approached Datamach of Coventry because they wanted support close by in case of any problems.

And indeed, this factor paid-off on one of the first production jobs which involved threading a very brittle insulation material.

As Alan Godwin describes: 'Bearing in mind it was our first venture into CNC.

We had just completed the training course with Datamach at our works instead of at their offices in Coventry due to the amount of work that was stacking up to go through the new machine.

We knew how difficult the material was to machine and so kept putting it back until we plucked up the courage to have a go.' He follows on to describe how they tried to thread the part using all the skills built-up from conventional turning but still the part shattered.

In the end a telephone plea for help to Datamach's technical support team resulted in a suggestion to use a G76 program to give better control of the process than the G78 that had been used.

'Although it took 10 passes to produce the thread it was perfect and demonstrates perfectly what we had been missing for years by using conventional methods.' Amongst other early tasks for the Tornado was production of large numbers of components made from very expensive high grade epoxy material and a tolerance of +0.025mm.

'By then, such was our confidence in the machine that we checked parts every hour.

But so good was the repeatability and consistency of the Tornado, that it produced the order without a hitch,' he maintains.

British Micanizing Co is a true specialist in its sector with 80 live customers at any one time out of 160 or so that are on the books.

There are a wide variety of components flowing through the Great Barr workshop including insulation screws, distance spacers, heat and electrical insulation parts for powder coating plants, transformers and insulators for the major electrical suppliers.

As Alan Godwin outlines: 'We often have customers just arriving on our doorstep with a drawing or sample part.

At times, they don't even know what the material is.

However, we can usually solve the problem as our strength is that we have probably machined a similar part before and there is so much knowledge in our company with some of our people having been with us for over 40 years!' He then relates how they still have on file old specification books and describes how customers still ask for Bakelite.

'We still have some Bakelite but you can't buy it anymore and we also have one of the best old insulation materials you can get called Mica.

However, because it is a glue-based insulator product, components can only be produced from it once.' batch sizes at British Micanizing vary between 80 and 20,000 parts.

While the Tornado has a 6,000 revs/min spindle powered by a 11kW motor, the company rarely runs the machine over 2,000 revs/min due to the nature of the materials being cut.

It uses standard carbide cutting tools with coolant in order to control the heat generation and reduce risk of damage or melting of some of the materials.

Alan Godwin describes how when they machine laminate materials they tend to chip into fine dust which the extraction system carries away.

'Nylon can be messy,' he says, 'its very stringy and wraps around the tools and if swarf builds up it can burn.

However, the flexibility of the Tornado means we have better control when machining this increasingly popular insulating material.' So productive is the A90 with its MBF 1000 bar feed that it will produce 5,000 parts in two days as against at least five days before.

'Also, we previously had to purchase precision ground rod which is at least three times more expensive than standard bar so we now save on material as well as machining time,' he said.

Changeovers are quicker than before taking up to 20 minutes which includes the bar size for the MBF 1000.

As Alan Godwin concludes: 'Investing in the Tornado has transformed our production and opened new markets for us.

When we first made the decision to buy, we thought we would need to run it all day, five days/week to get any pay back and saw the real opportunity as being the ability to take on new work.