Presetting plus

Courtesy of Zoller  Connectivity converts presetters into shopwide productivity boosters.

Productive machining is all about keeping spindles turning and making chips. Time spent touching off tools, adjusting tool length and offsets in the spindle and doing test cuts is time—and money—wasted.

That’s the value proposition presented by manufacturers of tool presetters, and it’s one that, surprisingly, is a bit of a hard sell in some shops.

“If you think about the costs of not presetting, it’s surprising there are still a lot of shops out there that don’t do it,” said Michael Stepke, regional manager for presetter manufacturer Zoller Inc., Ann Arbor, Mich. “It’s not just keeping the spindle turning. There are also costs associated with test cuts and scrap.” 

According to Stepke, many shop managers are looking for a quick return on investment and don’t necessarily see it in presetter technology. “A lot of small to medium-size shops want to know: ‘How fast can I get tools to the machine and start saving money?’ But there is a learning curve associated with being able to efficiently set the tools and use the presetting machine correctly,” he said.

To combat such short-term thinking, presetter manufacturers generally provide a ROI spreadsheet to potential customers, who fill in the specifics of their operation, such as the number of machines and shop rate, to get an idea of the payback period on a presetter investment.

Consider, for example, a shop running four CNC machines two shifts a day, with a shop rate of $80 per hour. If each machine requires one hour of tool setup per shift, the shop is losing $640 per day, or $160,000 per year, to spindle downtime. Using an offline tool presetter would eliminate that setup time, and reduce test cuts, scrap and rework as well.

Focus on Software

In addition to cost savings, presetters offer shops a way to link tool measurements—typically gathered through noncontact methods—to other equipment. 

Although some manufacturers still sell contact-type machines—essentially height gages for measuring tool length—the current state of presetting technology is based on noncontact measurement and analysis of not only tool length but runout and condition of cutting edges. Machines essentially provide specialized vision inspection, complete with CCD cameras and LED ring lighting.

Ease of use is an important consideration when purchasing such a complex piece of equipment, so much attention is given to the software being developed to operate the new breed of presetters. “Most of our improvements have been in the area of software,” said Hilary Schnirring, product specialist—tool measuring systems, BIG Kaiser Precision Tooling, Hoffman Estates, Ill. “Our freestanding machines can be automated with CNCs. This is especially helpful for setting complex tools, such as hobs or profile cutters.” BIG Kaiser represents Speroni presetters in North America.

Zoller’s smile presetters require only that the operator brings the tool into the machine’s field of view. The unit then automatically “snaps to” the tool’s cutting edge, auto-focuses and measures the tool. Based on inspection results, the machine displays whether a tool is out of tolerance using red or green indicators. It can also print a bar code label that is attached directly to the tool, which can then be placed on a tool cart or moved to the CNC machine for placement in the toolchanger.

Making Connections

But new software is not only aimed at making increasingly complex presetters easier to use. Connecting the presetter to CNC machines and, increasingly, to other manufacturing software is growing in importance. 

According to Schnirring, BIG Kaiser’s Speroni presetters can be directly connected to CNC machines for uploading of tool offset data, integrated with a shop’s CAD/CAM system to give users access to tool data during programming, used with a bar code or radio frequency identification system to automate tool data exchange, or integrated with tool management software, automated tool storage systems or dispensing machines.

Stepke also reinforced the importance of software connectivity to maximize the utility of presetting technology. Zoller’s global staff includes more than two dozen engineers working exclusively on software development, and most of the work is aimed at tighter integration with other shop computer systems.

“The presetter is not a stand-alone machine anymore,” Stepke said. “For every machining process a shop does, we can develop an interface or software to help them get better. Used properly, a presetter is a tool for continuous improvement.”

Much of the development work is aimed at integrating data from the presetter with CAD/CAM software. For example, Zoller has an interface with Tebis CAD/CAM software that lets users scan the tool, generate a 3-D model, import it to Tebis and simulate the machining process, according to David Morley, Zoller’s product manager for tool management software. The company has interfaces with Mastercam and VeriCut and is working on similar arrangements for GibbsCAM and SolidWorks CAD/CAM, he added.

Courtesy of BIG Kaiser

Typical of modern presetters is the Speroni MAGIS, which provides noncontact measurement and analysis of tooling. Machines are essentially specialized vision inspection systems, complete with CCD cameras and LED ring lighting.

BIG Kaiser has software integration with Mastercam, GibbsCAM and Delcam systems and can interface with any CAM software, according to Schnirring. “Basically, you can export tool data from the presetter to the CAM software to help programmers decide what tools to use to make a specific part,” she said. “Integration even lets programmers go down to the tool component level to make sure all the parts needed to build a specific tool are in stock and find out if they’re in use.” 

BIG Kaiser’s Speroni presetters also interface via MTConnect, the developing standard to facilitate the organized retrieval of process information from NC machine tools.

Toolroom Presetters

Tool management is the other main area where integration of tool data from CNC presetters is being used. “In many shops, tool preparation is moving away from the machine operator,” Stepke explained. “Probably the ideal place for a presetter is in the toolroom. It’s a more controlled environment, and presetting there gives shops better control over tool inventories.”

According to Stepke, improved inventory control alone can sometimes justify the cost of a presetter. Integration of presetter data with tool management software can cut tool cost 20 percent just by reducing inventories, he noted. Such a tool management system can also automatically order tools when inventories reach preset levels or alert toolroom personnel that inventories are low.

On the other hand, some shops place presetters on the shop floor, in some cases adjacent to CNC machines. “They’re precision measuring machines, but their construction allows them to be placed on the shop floor,” Schnirring said. She cited a manufacturer of titanium aerospace components that purchased a presetter to preset tools for a large, multiple-pallet machining cell. 

Bringing in Balance

Presetting tools for size is important, but tool balance is something that shops looking to maximize machine productivity should not ignore, according to Brendt Holden, president, Haimer USA LLC, Villa Park, Ill.

“We make toolholders, balancing machines and shrink-fit toolsetting machines, so we spend a lot of time in toolrooms,” Holden said. “Often, what you’ll see is a shrink-fit machine or an assembly bench, a presetter and a balancing machine. They all kind of work together, and that’s why we offer a machine that combines balancing and presetting.” 

Courtesy of Zoller

Operator display from Zoller machine shows the tool assembly, cutting edge, and other parameters in a graphical format. 

Holden said tool balancing is often thought to be necessary only for high-speed machining, but that many shops can benefit from fine balancing toolholder assemblies at all rpms. “Our biggest growth market for balancing machines sold is in larger production shops with machines running no faster than 8,000 to 10,000 rpm,” he said. “That’s surprising to a lot of people, because everyone thinks balancing is really only needed for high-speed machining. It can actually increase productivity in most applications regardless of the spindle speed, and of course there is an absolute need for balance just to protect spindles that are running at higher speeds.” 

But, he added, using balanced tools for lower-speed operations can improve performance in other ways. “For example, in one boring operation, the user was able to triple spindle speed from 300 to 900 rpm with three times the feed rate while maintaining hole dimensional and surface finish requirements,” Holden said. “Balancing can also improve tool life and workpiece surface finishes in, for example, facemilling operations that might run at 3,000 rpm.”

Courtesy of Haimer USA

Haimer’s latest balancing machine is a CNC unit that automatically measures and compensates for unbalance in one or two planes by drilling, milling or grinding the appropriate spot on the toolholder.

Haimer machines provide dynamic tool balancing using sensors to measure centrifugal forces being applied against the spindle as it rotates to determine how out of balance a tool is. The company’s latest machine is a CNC balancing unit that automatically measures and compensates for unbalance in one or two planes by drilling, milling or grinding the appropriate spot on the toolholder. Holden said the system eliminates errors such as those caused by incorrect marking of the toolholder or incorrect drilling depths.

Shrink-fit toolholders make up a significant portion of Haimer’s toolholder sales. Holden believes their use will increase in the future, and Haimer offers an integrated shrink-fit preset machine, along with a balancing preset unit. “Right now, the worldwide toolholder market is about 40 percent shrink-fit, but there are three application areas where the use of shrink-fit holders is much higher than that,” Holden said. “One is aerospace, where shrink-fit has become almost the standard for milling applications. Another is die-mold machining, because shrink-fit holders tend to be slim and also have inherent balance. The third is medical parts production, which often involves high-speed machining of small parts and also a lot of 5-axis work.”

BIG Kaiser also offers an integrated shrink-fit toolsetting and measurement system. The company’s Speroni EZShrink includes setting sleeves, automatic and fully integrated tool height adjustment, multiple-frequency heating coils, an integrated cooling unit and CCD vision. 

Improved software is enabling presetters to interface with other manufacturing software in ways that can save money throughout the shop. “The basic principle of presetting has not changed, but the whole idea of how the presetter is tied into different types of manufacturing software is evolving,” Stepke summed up. “With the appropriate software interfaces, users can really streamline their tool setup and management processes.” CTE

About the Author: Jim Destefani, a senior editor of CTE and MICROmanufacturing magazines, has written extensively about various manufacturing technologies. Contact him at (734) 528-9717 or by e-mail at jimd@jwr.com.

Using automatic size compensation for boring tools 

Knowing the size and condition of a tool before machining is important, but what if shops could not only know the diameter of a boring tool but also get automatic, wireless diameter adjustment size of boring tools to within 1µm?

That is exactly what users get from the ActiveEdge boring system with automatic diameter compensation. Developed by Rigibore Inc., Mukwonago, Wis., the system requires no modifications to the machine spindle, only an interface connected to the machine tool control and software that links the components via radio frequency (RF).

The tool can be adjusted by interfacing directly to the machine tool control or from data received from a presetter, probing or an inspection station. Up to four tools can be simultaneously adjusted from individual machines and while they are in the tool changer, minimizing cycle time lost to adjustment.

Tools can be automatically reset after an insert index or change. The presetter knows the established preset diameter and compares that to the size measured after the insert index or change. The tool is then automatically adjusted through data received from the presetter and that data is sent to the tool via an interface connected to the presetter.

ActiveEdge tools feature a yoke next to the shank, which houses a replaceable power pack, wireless hardware and electronics control capable of controlling up to eight cartridges in any one bar. The adjustment means and measuring device are housed in a replaceable cartridge, which connects to the control electronics when assembled in the bar.

According to Product Manager Greg Cocks, the system is ideal for “lights-out” manufacturing operations. “You’re eliminating the need for an operator to be present to make adjustments to the boring bar, and there’s no possibility for error,” he said. “So it’s really providing automated in-process measurement and control for boring.”

—J. Destefani

Contributors

BIG Kaiser Precision Tooling Inc. 
(847) 228-7660
www.bigkaiser.com

Haimer USA LLC
(630) 833-1500
www.haimer-usa.com

Rigibore Inc.
(262) 363-3922
www.rigiboreinc.com

Zoller Inc.
(734) 332-4851
www.zoller-usa.com