CNC production lathe spurs model company growth
February 28th 2009
Instead of using ‘trainer’ type lathes, model steam locomotive building company purchased a CNC slant bed production lathe, which proved to be a catalyst for company growth.
Three years ago, when 46 year-old ex-toolmaker Andy Clarke gave up his 20-year career in the construction industry to return to engineering and bought Polly Model Engineering, his friends thought he’d gone off the rails! But today, the man and wife business of making miniature steam locomotives up to one metre long and able to carry up to 8 people in carriages that can travel at up to 15 miles an hour, is certainly on the right track and is about to expand by at least a third over the next 12 months.
Key to this expansion plan has been the installation of a CNC slant bed production lathe from Colchester Sales of Heckmondwike.
Normally, model makers go for bench-top training type machines, but not Andy Clarke.
Alongside a vertical machining centre installed last year in his small workshop in Long Eaton near Nottingham, now sits a full size Colchester Tornado A90 CNC lathe.
And, as a result of the acquisition, he now has the capability to automatically batch machine under his own control all the parts for his locomotives and driving trucks except the boilers which are purchased fully certificated from specialist subcontractors.
Says Andy Clarke: “As an example of how the business is developing, my wife Jayne and I went to a two-day show in April and sold models equal to almost half my present year’s production.
Demand is rising so fast from all over the world that I had to develop batch making techniques, and the Colchester lathe is so ideal for this.
I turn everything, even though I have never been on a CNC course in my life, and the parts include wheels, axles, motion parts, buffers, valves, piston heads and cylinders, steam chests, steam connectors, brakes, smoke box and parts for cabs, tenders and tanks.” When he took delivery of the Tornado he maintains he didn’t even know where the on-button was.
“Within a week I was making bits and found the machine so easy to use.
Where I used to buy castings, I can often machine direct from bar now and so far have programmed about 250 different parts, which I can run-off as and when I need them in batches of 100 or so.” There are five easy-to-assemble steam kits in the Polly Model range aptly designated Polly 1 to Polly V.
Polly V is the latest addition and is a 5 inch gauge 2-6-0 tank locomotive some 37 inches long by 10 inches wide, weighs 54kg and is powered by 5 inch driving wheels.
Customers are as diverse as solicitors, a church organ restorer, a retired policeman and a lorry driver in Scotland who bought one for the track in his front garden! And there are currently two women who are building locomotives from kits to which Andy Clarke confirms: “From my contact with them, they are progressing very well”.
Clarke normally links customer build to production, by selling each locomotive in 12 separate kit packages.
Customers order the engine which can cost between GBP 3,000 and GBP 5,000 and pay a 20 per cent deposit.
The remaining 80 per cent is then split over 11 months in exchange for the next monthly set of parts and build instructions.
Although he admits one young lad does get special treatment and phones him every time he has some extra money and asks ‘what can I buy for this?’ This ‘pay as you go’ purchase also helps him organise the batching of parts.
“With the Colchester Tornado, not only do I know that the tolerances, surface finish and quality will be consistent over the batch, I can press the button - make the bits while I get on with something else.
“OK if the part is a casting, I just reload the machine as I pass by but I use a bar puller and machine a batch of parts from bar in one go.” He maintains: “I’m not after cycle times, it’s all about quality.
When you are selling to South Africa, France, Germany, Denmark and very soon the USA, these keen model enthusiasts will not tolerate inferior parts.
My reputation is at stake with every engine I make because enthusiasts are very keen to talk to each other.” He then describes how the Colchester machine has proven its worth.
“Castings for cylinder covers used to cost GBP 2.50 and I always had to wait for delivery.
Today I turn them completely out of bar, along with a host of other parts such as safety valves, miniature boiler fittings and bushes.
Even crank pins are produced out of bar as well as miniature drain cocks a quarter of the size of a small finger nail.” Larger parts such as smoke boxes, which are 8 inches diameter by 4 inches long are all turned from aluminium castings and he claims to machine six months stock of wheel castings in around an hour.
“That would have taken me days before on an ageing capstan and centre lathe installed in a corner of the workshop, and it would have demanded all my skills as a toolmaker to get the parts right.” In particular, the brass dome that sits on top of the boiler is now produced from a lost wax casting.
“I programmed and turned the blank for the casting in under an hour,” and he proudly demonstrates the smoothness and finish of the blend radii of the dome.
Having recently purchased a mail order model engineering supplies company, Bruce Engineering, which is now run by wife Jayne and supplies proprietary model parts such as steam stop valves, injectors and water gauges, the Polly Model workshop is almost bursting at the seams which might mean a move to new premises.
Sales have climbed by almost 75 per cent in the three years he has been trading and Andy Clarke now plans for further growth and diversification of the business.
“Before the Tornado was installed and with just me making parts I could never have improved the business.
Skilled labour is very expensive, sub-contract machining would mean I could lose control and so decided the latest turning technology would give me what I needed.
I can’t believe how right that decision was!”.