Lathes have many uses, some of which are less conventional than others, like gear skiving. A case in point can be seen at one of Europe’s largest specialist manufacturers and suppliers of gear racks, pinions, leadscrews and nuts, Halifax Rack & Screw (HRS), which has recently started producing round gears at its Brighouse factory in West Yorkshire.

For machining round gears accurately and quickly, the firm has invested in a gear skiving machine: an Okuma Multus U3000-2SW from NCMT. Already installed and operational, this bar-fed, multi-tasking lathe is about to be fitted with automation equipment to further speed the handling of components, free up more operator time and make the process even more efficient.
Sales engineer at HRS, Simon Matthews, who has been heavily involved in the project, says: “For the medium-to-large batch production of gears, skiving has become the technology of choice. For example, in the case of the first three gears we are producing for our US customer, Vermeer, the 25 minute cycle times for the two larger gears would be three to four times longer by hobbing or using other gear cutting machines. We opted for the Multus from Okuma, as it was the first multi-function machine manufacturer to develop a generic platform for skiving precision gears to DIN5 quality.”
A crucial element in gear skiving on a multi-tasking lathe is being able to synchronise accurately the B-axis rotary movement of the upper tool spindle carrying the skiving tool, with the C-axis rotation of the main spindle – functionality for which the Multus is noted.
For further information www.ncmt.co.uk

Even in its standard version, the C200 lathe built in Germany by Index-Werke is a productive bar auto with three turrets and two spindles that are horizontally opposed. Now, the manufacturer has introduced a tandem version with two main spindles mounted side by side and two counter spindles for even more cost-effective production. Sole sales and service agent in the UK, Ireland and the Middle East is Kingsbury.

The new Index C200 tandem, which has an identical machine housing to that of the original lathe, doubles production output in the same footprint without increasing labour or energy costs. Each of the three VDI-30 tool turrets, which can be used simultaneously, have remained the same in terms of their arrangement, power, speed and feed rate.
New, however, is the turret design, which enables five double tool holders to be mounted. Each side is equipped with identical tools in pairs, fixed or live, which are used in parallel at the main and counter spindles for simultaneous front-end and rear-end machining.
Bar stock up to 52 mm diameter is fed by the specially developed Index MBL52 tandem magazine, allowing two bars to be advanced into the lathe at the same time. An integrated handling device was also developed, whereby two grippers ensure that the pair of machined components are removed from the counter spindles and placed on a conveyor belt to exit the machine quickly and without damage.
Index’s patented SingleSlide guide system remains in use for the tandem version of the C200. Kinematically driven steel plates replace compound slides for supporting the three turrets, significantly reducing the distance between the turret centreline and the point at which it is driven.
For further information www.kingsburyuk.com