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Shop Cashes in on Large Subspindle

March 25, 2008
For its shock absorber component machining, Hagon Products benefits from the Tornado’s ample Y-axis off-centerline capability. When looking to increase its turning capacity, Hagon Products, based in Hainault, ...
For its shock absorber component machining, Hagon Products benefits from the Tornado’s ample Y-axis off-centerline capability.

When looking to increase its turning capacity, Hagon Products, based in Hainault, Essex, England, initially focused on C-axis and driven tooling, then it looked at a subspindle machine.

However, the company had a hard time finding such a machine that supported a larger-than-standard subspindle capacity, until it came across the Colchester-Harrison (www.colchester.co.uk) Tornado T8MSY turnmill center through RK International.

Hagon discovered that the Tornado could be modified to accept diameters up to 45 mm (1.77 in.) and that its Y-axis option for off-centerline travel of +/- 40 mm (1.6 in.) fit perfectly into future production plans.

There were also other advantages, Brian Green, production manager at Hagon, said.

The Tornado’s 12-station, all-driven 3.7-kW, 5,000-rpm VDI turret was compatible with all of the shop’s existing tooling, as were many of the part programs for its Fanuc control. Moreover, visibility for the machine’s work area far surpassed other machines, and a larger parts catcher, working height and tooling layout proved equally advantageous, Green added.

The Tornado has reduced machining times and allowed Hagon to combine three previous operations into a single cycle. The shop also uses the machine’s subspindle and Y-axis turret crossfeed to generate off-center features, keyways, flats and contoured milled surfaces along with performing helical milling.

Hagon produces motorcycle shock absorbers, some 45,000 per year. It purchased the Tornado to handle larger variants of its Monoshock range of shock absorber bodies.

“We needed a larger capacity 65-mm (2.56-in.) machine, and found the Tornado would be ideal,” Green said. Also, the machine easily turns the shop’s 63-Rc induction-hardened piston rods and generates perfect surface finishes, he added.

The Tornado 6-axis turning center features a main spindle drive of 22 kW and 5,000 rpm and a subspindle of 7.5 kW and 6,000 rpm. Both have full C-axis and disk brakes to maintain spindle positioning when machining off-center.

By transferring components on-the-fly from the main to the subspindle, additional turning and milling operations are possible for completing parts in one cycle. In addition, the 40-mm (1.6-in) Y-axis travel on each side of the machine centerline allows Hagon to take full advantage of the machine’s milling capability and rigidity.

Hagon quickly put the Tornado, equipped with a 1.5-m (59.0-in.) Iemca barfeeder, to work producing a multitude of complex parts and soon registered a payback by reducing operations, cycle times, handling time and minimizing work in progress.

For example, the shop previously produced a shock absorber end fitting made from aluminum for a BMW Monoshock motorcycle in three operations using a CNC lathe and vertical machining center. Today, the part is made complete in one cycle that runs less than 5 min on the Tornado.

After feeding out raw material, the shop rough turns the end fitting and, using the Y-axis turret, produces a large hole using helical interpolation with an 18-mm end mill. The component feeds out further, and the machine cuts a profile taper on the part’s main shank. The part then transfers to the subspindle where its other end is turned and a cross hole machined and internal features produced.

Prior to the Tornado, monoshock tube body lengths were first cut on bandsaws and turned individually in batches of 2,000.

Now, processing is continuous, with each thin-walled body being machined complete on the Tornado, including in-cycle deburring.