Leader quick-change Lexon collet chuck keeps ATC operating smoothly

Citation

(2004), "Leader quick-change Lexon collet chuck keeps ATC operating smoothly", Aircraft Engineering and Aerospace Technology, Vol. 76 No. 4. https://doi.org/10.1108/aeat.2004.12776dab.014

Leader quick-change Lexon collet chuck keeps ATC operating smoothly

Leader quick-change Lexon collet chuck keeps ATC operating smoothly

Keywords: Leader Chuck Systems, Turning, Collet chucks

The speed of changeover and accuracy and reliability of the Hainbuch Lexon collet chuck from Leader Chuck Systems (www.leaderchuck.com) were the prime reasons why ATC specified the chuck when it invested in a Nakamura-Tome WT150 seven-axis turning centre as part of its continual investment programme (Plate 2).

Capable of fast changeovers, Lexon has a runout accuracy of only 5 μm and is designed as an economical replacement for multi-bore and other styles of collet chucks in bar-fed turning applications. It boasts 30 per cent more gripping power than multi-bore systems, so allows faster machining speeds and feeds and therefore generates reduced cycle times. In addition, its extra rigidity promotes increased tool life and improved surface finishes compared with other bar-fed lathe chucks.

Plate 2 Leader's Hainbuch Lexon collet chuck provides ATC with fast changeovers and accurate workholding on its Nakamura-Tome turning centre

As a specialist producer of components in medical grade stainless, titanium and cobalt chrome, for example, primarily to the medical and aerospace sectors, ATC's 5,750 m² site at Redhill, Surrey, houses an impressive portfolio of high-tech production equipment.

“We always like to keep up-to-date with the latest machining technology”, explains sales director William Sanders. “That way we stay ahead of the competition in terms of our ability to consistently produce cost-effective and high-quality parts.”

In addition to sliding head lathes incorporating thread whirling and milling as well as gun drilling, the company's turning section also features fixed head lathes, and it was to maintain the highest performance standards in this section – “and particularly our ability to produce complex turn-mill components in a single setting from multi-spindle, twin turret machines,” comments William Sanders – that the Nakamura-Tome was installed.

Capable of handling bar of 51 mm, the Nakamura-Tome WT150 supplied by Mills Manufacturing Technology boasts main and sub-spindle speeds both of 5,000 revs/min (15 kW on main spindle; 11 kW on sub-spindle), and two by 12-station tool turrets. It is a seven-axis machine, with c axes on both spindles and y axis on the top turret. Maximum turning diameter is 190 mm and maximum turning length is 400 mm.

A 65 mm Lexon chuck was specified for the machine, says Williams Sanders, primarily because of the fast changeovers possible with the system – in some cases just 6s compared with the traditional 15 min!

“In addition to acknowledging that the reliability and accuracy of Hainbuch collet chucks are essential to our business, the fact that we have other Hainbuch systems in use on our fixed-head lathes also means that we want to standardise on our chucking as much as possible,” he adds.

In addition to their accuracy and quick-change features Hainbuch collet chucks, which will accommodate workpieces up to 500 mm diameter, also differ from standard chucks in being able to securely hold short component lengths due to the positive pull-back and clamping action – the clamping head being pulled into a perfectly mating taper.