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Toolholding eases dental-chair production pains

April 1, 2005
A-dec is a North American dental supplier focusing primarily on ergonomics. Its latest product is the A-dec 500 dental chair that maximizes patient comfort and eliminates factors often leading to spinal and vascular problems in dentists.

The Coromant Capto modular toolholding system extends A-dec's tooling reach without sacrificing speed or accuracy.

A-dec is a North American dental supplier focusing primarily on ergonomics. Its latest product is the A-dec 500 dental chair that maximizes patient comfort and eliminates factors often leading to spinal and vascular problems in dentists.

As the chair's design evolved, A-dec engineers realized that a smaller baseplate would allow dentists to work closer to patients without having to bend at the waist, which can cause fatigue and eventually spinal damage. However, the new, smaller baseplate, made of cast iron and weighing 120 lb, was hard to machine because of tool reach and reliability difficulties. So the company incorporated Sandvik Coromant's Coromant Capto modular toolholding system, which increases tooling reach without sacrificing speed or accuracy.

"By stretching out the Capto and then putting a hydrogrip chuck at the end, we got tool length to where it was needed," says Brian Cappoen, senior programmer at A-dec. "With the setup, we hung drills out 18 in. and held tolerances of 0.001 in., while still getting through narrow passages in the fixturing to reach machining areas."

Demand for the new chair grew, and A-dec needed to increase production. The company again turned to Sandvik and joined its Productivity Improvement Program (PIP). Sandvik Coromant specialists spent a week at A-dec working with its machinists to gather data on parts causing bottlenecks, one of which was an upper-structure chair component.

Two of the 17 tools required to complete this part consumed huge amounts of time, an end mill that roughed and finished the part and a second specialized tool that machined a pocket. The whole process originally took 40 min, which A-dec programmers got down to 28, but this was still too long.

The PIP report suggested a CoroGrip precision toolholder combined with a Coromill plura end mill. The combination let Bayside increase feedrates from 30 to 60 ipm and slash cycle time to just over 11 min.

After nine months of integrating PIP-team recommendations, A-dec estimates that, on an annual basis, it has eliminated close to 4,000 machining hours from its processes. In addition, weekly production runs are up 50%, solely from tooling changes.

Sandvik Coromant
Fairlawn, N.J.
sandvik.com/us