Shaving More Seconds Off Quick Changeover

One of the critical measurements of machine shop productivity is equipment uptime, where improvements in a few minutes or even seconds can make a big competitive difference. Shorter tool change cycle times in job shops can add up to hundreds of thousands of dollars annually. “One of the major factors behind our decision to incorporate a quick change system is our goal of improving setup time from minutes to seconds,” says Jimmy Lytle, the president of Daystar Machining Technologies, Inc. (Fletcher, NC).

Daystar offers stamping, punching, forming, welding and other fabrication services, along with state-of-the-art CNC turning and milling centers focused on precision machining with quick turnarounds for short run, prototype and specialty-part production. Making quick tool changes and improving tooling life is a high priority for the 35 employees in this family-owned 27,000 sq ft job shop, where the flexibility and stability of the quick change system is used to reduce capital investments in tooling.

Perhaps the most noteworthy recent development at Daystar was the introduction of the versatile BENZ Solidfix modular quick change collet system from BENZ Inc. (Charlotte, NC) that enables machine operators to perform setups and changeovers in speeds of 15 seconds or less. The shop recently installed the system on two new lathes, live tooling Y-axis machines. “We use quick change adapters on all the live tooling for those lathes,” explains Lytle. “We can set the adapters out on the work bench and get everything ready for a setup. Then we are in and out of the machine very quickly.”

A demonstration of the BENZ Solidfix modular quick change system.

These adapters are a central advantage of this new quick change system because they feature a compact design with a large planar contact surface for high transmission of torque and high rigidity when milling at high speeds. Their play-free centering of taper maintains high concentricity of less than 5 µm on 30 mm, with high repeatability of central, cross-force-free transmission of forces.

The adapters are attached to individual tools and are quickly and easily inserted into a head via a bayonet-type mount that is then secured by simply turning a single nut using an Allen wrench. Various popular soft tools, such as live turrets, angle heads and static tools, can be interchanged with different size adapters. The system will fit older machining equipment as well as newer models.

This modular quick change system saves the shop several minutes of time for each setup when compared to using conventional tooling that required operators to take out their driven tools, remove and clean the collet – a relatively cumbersome operation requiring the use of two hands and multiple tools – then install the new tooling and take offset measurements. All of that could easily take two or three minutes.

But using the BENZ Solidfix system, operators no longer have to remove the main tooling unit itself. Now they simply use one hand to change the adapter that holds the pre-measured tool. They can change a setup in less than 15 seconds without using any special tools. This also means that the shop doesn’t have to buy as many expensive live tools because all they have to do is buy the quick change adapters.

By utilizing this quick change system, Daystar can reduce the number of live tools or angle heads because the spindles can be changed from ER collet to mill arbor adapter, Weldon or Whistle Notch adapter, shrink fit, and various special tooling. “We are now able to switch from a collet chuck to a shell mill adapter to a solid end-mill holder without having to change to a different live tool holder for every application,” notes Lytle. “Using this quick change system, we have one somewhat expensive tool holder, but everything else is fairly inexpensive. This gives us a great deal of versatility without a major capital investment.”

This modular system takes original quick change technology and simplifies it. Instead of requiring operators to spin on and tighten tooling in the holder using a wrench, BENZ Solidfix requires only a simple turn of an Allen wrench. Also, in a traditional quick change system the operator has to remove the tool, install a new tool, and then they have to touch-off their tool to ensure the offset is correct. But now they can preset tools on a granite surface plate and, when the tool starts wearing or another type of tool is required, they simply insert and secure the new tool.

“Essentially, they’re putting the whole tool aggregate back in with repeatability that is so accurate they can program in what they just measured off their height gauge. This means they don’t have to go through the scenario of touching off the tool and then programming the offset,” states Mike Starnes, a sales application engineer for BENZ. “So this is really a plug-and-play system where the operators just switch out the soft tooling and they’re all set.”

Most importantly, this new quick change system is safe. When some operators try to cut corners and expedite a traditional setup, they can be exposed to injury. “Normally, the cutting tool they are removing is very sharp,” says Starnes. “Even if the spent tool is too dull to accurately machine a part, it is still very sharp to the human skin. If the operator gets cut while handling spent tools, the wound could be deep enough to require stitches. Even highly experienced operators must be very careful when handling cutting tools. When mishaps occur, they have to leave and go to the nursing station to clean up the wound. In more serious cases, they may have to travel to an offsite doctor or even the hospital.”

And, of course, when these sorts of injuries occur more production time may be lost. Because the ease of mounting and securing the adapter and tooling with this new system is easier, operators perform a much simpler task that minimizes exposure to potential injuries – and loss of equipment uptime.

Daystar Machining Technologies, Inc., 356 Cane Creek Road, Fletcher, NC 28732, 828-684-1316, Fax: 828-684-7223, [email protected], www.daystarmachining.com.

BENZ Incorporated, 8325 Arrowridge Boulevard, Charlotte, NC 28273, 704-529-5300, Fax: 704-529-5009, [email protected], www.benz-inc.com.