Latest investments cut labour costs by 700%

Labour cost down 700% and lead time reduced 3-fold to produce 100 valve blocks - the results of investing in latest twin-pallet HMCs and bar-fed turning centres with Y-axis tool actuation.

Eighteen months ago, Lancashire-based Clitheroe Light Engineering could only see work for 14 days ahead, but by June 2004 the order book had stretched to 11 months, a level of business that the subcontractor has not seen for six years.

The turnaround is partly due to stronger trading conditions now that manufacturing is coming out of recession, and partly to continued investment in modern machine tools capable of long periods of automated operation.

Since August last year, the family-owned company's first two horizontal-spindle machining centres (HMCs) have been installed - both Daewoo twin-pallet models supplied through Mills Manufacturing Technology.

In addition, a bar-fed, Y-axis turning centre with driven tooling from the same Korean manufacturer has been acquired.

Single set-up with minimal manning was the rationale behind the latest investments, which have seen the number of Daewoo machines on site increase to 11.

Said Chris Wilkinson, a director and one of five family members working at Clitheroe Light, "With increased competition from all over the world and the need constantly to reduce prices, it is difficult to justify having an operator standing in front of a vertical machining centre (VMC) repeatedly refixturing a component; and that's if you can find good people to do the job in the first place.

"Similarly, turning parts on a lathe and having them queuing for drilling and milling operations on a 4-axis machining centre does not make sense any more, as margins are so tight.

Our first step away from this was the installation earlier this year of a Daewoo Puma 2500SY 6-axis, twin-spindle lathe with +/- 50 mm of Y-axis movement, which is currently devoted to turn-milling six varieties of steel valve piston in one clamping - parts that were previously produced in two operations." He went on to point out that automated, one-hit production does not just reduce the labour cost content of component production, but also improves cash flow.

For example, batches of 100-off manifolds are regularly produced for a large US hydraulic valve manufacturer.

In the past, 30 or so parts would be machined on one face on a VMC and then the other faces would be sequentially machined in three more set-ups.

In this way, the subcontractor was able to keep the customer fed with valve assemblies, each of which might contain a dozen different components in addition to the manifold, many of which needed a similar piecemeal approach to production on other turning and machining centres.

"It played havoc with our cash flow, as we had to bear the cost of work-in-progress and it was some considerable time before 30 complete parts were ready for delivery and invoicing," continued Mr Wilkinson.

"Now the valve manifolds come off either of the Daewoo HMCs complete after two set-ups, one on each pallet.

Four or eight at a time, according to which HMC is being used, so the manifolds are ready to invoice immediately." The original process was also vastly more expensive in terms of labour.

It used to take two operators up to six weeks, or 78 man-days, 24 hours a day, to complete 100 valve manifolds on two VMCs.

Moreover the machines had to be attended for a large part of the time; some operations took only a few minutes before the part had to be refixtured.

The new process on a Daewoo ACE HM500 takes one man just 11 days with significantly less need for machine attendance, resulting in a seven-fold reduction in labour and lead time down by a factor of three.

The new HMCs and the Y-axis turning centre have proved to be a useful sales tool for Clitheroe Light, as its principal customer has been so impressed with the new direction that the subcontractor is taking that it has increased the level of business to include components that were previously produced in the US.

Cost-down was part of the deal, but production savings derived from automated techniques allowed room for manoeuvre.

Mr Wilkinson also says that the new approach has improved morale internally, as repetitive, boring jobs are being eliminated and people feel that things are moving in the right direction.

Mills' after-sales service is singled out for praise.

The latest ACE HC400 was installed and connected up within 48 hours and the HMC was running flat out within two weeks with the help of initial programs and fixturing advice from Mills.

Training has been impressive too.

The engineer that comes to the Clitheroe site is just as competent at teaching 6-axis lathe programming and operation as he is at instruction on the HMCs.

This flexibility allows Mr Wilkinson to choose which staff to train in which discipline as needs dictate, rather than having to book separate weeks for turning and prismatic training.

Clitheroe Light decided to extend the versatility of the HC400 after installation by retrofitting a magazine to treble capacity from 40 to 120 BT40 tools.

In addition, the machine was equipped with Renishaw MP10 probing and tool monitoring was added within the Fanuc CNC.

Now the subcontractor has better control over production cycles that involve sensitive machining operations.

For example, vulnerable bores can be checked for the presence of a broken drill before a reamer goes in.

If a blockage is detected, that component is disregarded for the remainder of the cycle, which is completed using sister tooling.

The situation is remedied after completion of the pallet.

Renishaw probing and Fanuc tool monitoring have also been fitted to the other HMC, which has a 60-position BT50 tool magazine.

Concluded Mr Wilkinson, "The competitive price of Daewoo machine tools, which are around one third less than equivalent turning and machining centres from other suppliers, has allowed us to expand into top-end, automated metalcutting technology earlier than would otherwise have been possible.

This has increased our business, improved profitability and almost eliminated scrap and concessions; we are chasing a 0.1 per cent scrap rate on the latest Daewoo machines.

"Their installation has accelerated what until now has been steady growth for our company since it was formed in 1971.

We have trebled our factory space to 10,500 sq ft in the last eight years and are now in a position to buy our first property in the Clitheroe area.

"Another benefit of 24/7 automation is that we are able to consider large volume work, from the automotive industry for example, whereas previously we would have shunned this work because margins are too slim if you are using labour-intensive production methods.".

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