Measure of success for DTI scrap-rate scheme

A DTI-backed scheme to reduce scrap rates in small companies has saved £200,000 and attracted additional orders of £900,000 for 20 companies in West Yorkshire.

Under the On-Machine Measurement project, companies borrowed sophisticated calibration and measurement machines on a 90-day free trial from makers such as Renishaw, the Bowers Group, Faro and Taylor Hobson.

As a result of the success of the pilot, the DTI is putting up £150,000 to run similar schemes in Bristol and St Helens.

Dr Jerry Benson, director of technology transfer at the National Physical Laboratory, part of the consortium running the scheme, said many small companies in manufacturing have high scrap rates compared with best practice.

‘Many don’t know how to control the manufacturing process. They will buy a £70,000-£80,000 machining centre without realising that it needs calibrating to control the items being manufactured. Even if they know about best practice, smaller companies have enough problems as it is at the moment,’ he said.

Scrap rates caused by components being out of tolerance are 0.2% for the top 10% of companies. The average is 1.6%, but the last 10% are significantly worse.

One company in the pilot scheme, Pickersgill Kaye, used a ballbar machine to calibrate five CNC machining centres and found two out of calibration. One machine was put back into calibration using a laser alignment machine within one and a half hours, said production services manager David Wilcock.

Another, used to bore the barrel of a valve for a train emergency system, was cutting slightly oval bores. It was adjusted back to its as-new tolerance. ‘We were thinking of selling or downgrading it and buying a new machine,’ said Wilcock. ‘We were scrapping 10% of production. Now it’s 1%, and those rejects are for other reasons.’ The company has now bought a ballbar machine.

Measuring equipment manufacturers have traditionally had difficulty persuading small firms to buy their products. In this project, firms were initially approached by staff from Leeds College of Technology, another consortium member. ‘Because many apprentices were trained at the college there was a relationship of trust,’ said Benson.

Once problems had been identified through talks with the managing director or production director, the measuring machine makers were brought in to advise. ‘They have given a huge amount of time free of charge to make it work,’ said Benson.Typically the machines being offered on trial are relatively inexpensive: around £2,000 for a ballbar machine. The most expensive equipment used, a laser probe, sells for £6,000.

The Centre for Precision Measurement at Huddersfield University, also part of the scheme, offers advice to companies with more specialised problems.