A modern, turn-milling bar automatic is on average more than 10 times as productive as a previous-generation model from the same German manufacturer, says a leading lock producer.

A modern, turn-milling bar automatic from Traub is on average more than 10 times as productive as a previous-generation model from the same German manufacturer, says a leading British lock producer. It is well placed to judge, having replaced five lathes purchased in the mid-1990s - single- and twin-turret models, with and without driven tooling - with a new Traub TNK 36. Installed in July 2004 by UK agent, Geo Kingsbury, the German-built machine produces in a single shift the same number of lock cylinders that the five older machines turned out over two shifts and sometimes well into a third.

In addition, many of the components previously needed second operations, such as slot milling.

Anyone keen to compete more effectively, particularly with overseas manufacturers, will benefit from the significant cost savings that machines like the TNK 36 provide.

The high degree of automation takes away much of the advantage of low-wage economies, as the labour cost element of manufacture is reduced drastically.

This has been the lock manufacturer's experience.

Whereas six people were previously employed to operate the former production cell during each of two shifts, only two operators are now needed over a single shift, representing a 12-fold saving in wages.

So productive is the TNK 36 that lock cylinder production alone is not sufficient to occupy the machine, even for a single shift, despite 1.5 million locks being produced annually.

So other lock and padlock components have been added to the lathe's remit and there are plans to put on mortise and multi-lock components.

Currently, six variants of cylinder of 19, 24 and 36mm diameter in different lengths and styles are produced, plus additional components, in batches of 500- to 2,500-off.

In the former cylinder production process, the now-replaced Traub lathes turned and milled the components as far as the capability of each machine allowed.

Further operations were needed to complete the parts, involving manual handling onto milling, drilling and tapping machines.

Cycle time on one of the old lathes was two-and-a-half minutes on average, followed by one minute of secondary operations, plus handling time.

By contrast, cylinders are produced in one hit on the Traub TNK 36.

Each component requires 40s of machining, although one part comes off the machine every 20s - over 10 times faster than from the previous cell - by virtue of simultaneous cutting using the main and sub spindles.

Such comprehensive machining is enabled by a large number of tools, namely two in-line gang toolposts with five stations each (four of which are driven), one for front endworking and the other for reverse endworking; and a 12-station turret on which all stations are live.

Brass bar is fed through the main spindle from a Hydrabar full-length magazine.

Turning of the OD, facing, drilling and counterboring are all performed simultaneously, followed by drilling five pinholes, milling of a dovetail slot and part-off.

At the same time, the previous component, after having been picked up by the sub-spindle, undergoes machining of a back boss and has two holes drilled and tapped, followed by a chamfer turning operation to deburr.

A process capability of Cpk 1.66 was recorded during machine pass-off, while Cpk 1.33 is routinely achieved.

A spokesman for the manufacturer commented that the new Traub lathe is unbelievably flexible and can machine practically anything.

It means that the design department now has very few restrictions when working on new lock models.