The chase is over: Turning Performance

END USER: Micro-Tronics Inc., (602) 437-8995, www.micro-tronics.com.
CHALLENGE: Prevent sealed bearings from overheating in a live tooling head.
SOLUTION: A live tooling head with coolant-fed bearings.
SOLUTION PROVIDER: Planet Products Corp., (513) 984-5544, www.planet-products.com.

As live tooling becomes more popular in CNC turning centers, tooling with sealed bearings can pose a challenge for shops that produce parts in high volumes or with long cycle times. Most conventional live tooling designs have sealed bearings in the tool head, which may overheat during continuous use or under heavy loads. This may reduce performance of a precision machine, reduce tool life and result in frequent and costly maintenance issues.

Micro-Tronics Inc., a Tempe, Ariz., machine shop that produces metal valves, bearing races and related products for the aerospace and automotive industries, was facing the challenge of using conventional live tooling with sealed bearings. The shop produces 250 to 1,000 parts with cycle times of more than 30 minutes.

“If a shop produces high-cycle-time or high-volume parts, then thermal growth usually occurs in the tool head,” said Mike Thompson, lathe supervisor at Micro-Tronics. “The sealed bearings warm up after 6 to 8 hours.”

Thompson noted the occurrence of thermal growth requires offset deviations. “If you are holding really tight tolerances, you have to start moving your offsets around to hold dimensional size,” he said.

To avoid such problems, Micro-Tronics acquired a new type of live tooling head for its Puma 300M lathe. The tooling from Planet Products Corp., Cincinnati, has a coolant-fed bearing assembly.