APPLICATION: Machining Stainless Steel with Precise Tolerances
BACKGROUND: A Jergens customer manufactures differential and straight pressure transducers, precision measurement instrumentation and sensors for industrial, civilian and military aviation and defense applications, as well as for space exploration.
The manufacturing division specializes in the machining of stainless steel to precise tolerances, with very short lead times from initial order receipt to product shipment. Much of the parent company’s prototype development is also provided internally by this division. Common machining methods requiring indicating were used for decades on an aging Matsuura MC500v vertical machining center, and long set-up times were an everyday matter. “We were spending much more time setting up than machining, and we found ourselves falling behind in our commitments to internal customers as a result,” said the division’s senior CNC programmer. It was clearly time to upgrade our machining capability, points out the programmer, “and reducing set-up times.
- A typical lot size of 30 parts required a two-step process and 4.75 hours of machining time
- Combined set-up times were 4 – 5 hours
- Total machine time to set-up and run 30 parts averaged 9.5 hours
After extensive field research and exhaustive comparisons, the manufacturer purchased a new Mori Seiki NV5000A/40 vertical machining center with a high-speed spindle and high-pressure coolants to help minimize cycle times. With the concurrent need to reduce set-up times, the division also explored various “quick changeover” systems offered by leading suppliers, but found that the tooling costs per workpiece using many of these systems were prohibitive.
The simplicity and precision of the Jergens Ball Lock Mounting System provided the most appealing, costeffective alternative. The manufacturer purchased precision fixture plates from Jergens, pre-drilled with liner bushings in place to match subplates manufactured by Jergens with receiver bushings already installed. With the Ball Lock system, this Jergens customer’s changeovers became significantly faster as fixtures were removed with a single 1/8-inch T-handle hex key, and the next job was fastened down and ready to cut in less than 10 minutes. Major improvements in the machining process were realized:
- Machining time reduced to just under 2.5 hours for 30 parts – second operation eliminated
- Improvement: Nearly 1/2 the machining time
- Changeover time reduced to 18 minutes, with no need for establishing location or squaring
- Improvement: 90% reduction in set-up time
- Total machine time decreased from an average 9.5 hours to less than 3 hours to produce 30 pieces
ABOVE: Ball Lock System in action
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