When I think of current toolroom operations, I’m reminded of acartoon image showing an extremely modern factory. There are guidedvehicles buzzing around; robots with vision are loading machines; andsensors of every sort are watching, checking, gaging, and testing. Everything is slick, polished, refined–except off in one darkcorner, where a caveman is swinging a large club. He’s settingcutting tools. It’s not quite that bad, but in the course of our travels, weoften encounter tool-control systems that contrast the sophistication ofthe plant almost that much.
It’s surprising to find shops spending top dollar on thelatest CNC equipment, only to waste it with such outdated tool-controlpractices. The toolroom–one of the last parts of the shop to becritically examined–presents real opportunities to improve efficiencyand control for plants of every size. In this article, I’llexamine how to update your toolsetting, tool control and tool handling;we’ll explore the concept of toolroom automation. What is toolroom automation? It’s much like any other type ofautomation. By applying “systems” to specific tasks, we makemany operations automatic. In the toolroom, there are many ways toapply such systems. You can keep track of tools using a computer.
Using a”smart” toolsetting gage, you can automatically move the gageto the tool point. You can automate tool handling, inventory, anddelivery in much the same way other parts of a shop are automated. Granted, toolroom automation requires more flexibility than ahigh-volume manufacturing system, but the technology to implement thishas existed for some time. It’s much the same as that technologyrequired for effective machining cells, FMS, and factories of thefuture. In a nutshell, toolroom automation is how to bring tool-controlprocedures into step with the rest of modern manufacturing. Whyautomate the toolroom function? Nobody invests in automation for thesake of automation.
There must be concrete advantages–either shortterm or long term. In the toolroom, there are several important waysautomation pays dividends. Better toolroom operations improve tool-setting accuracy and helpensure use of specified tool geometries.
With automated toolsetting,greater consistency is achieved, but labor is also reduced. Finally, bytying the tool-control function into other manufacturing-controlsystems, you’re assured the best control of all tool-relatedvariables. Let’s look at each issue. Benefits Improved accuracy is one of the best reasons to gain more controlof toolsetting. Because toolsetting accuracy directly affects theamount of scrap produced, consistently accurate toolsetting is a must. Furthermore, with untended machining, there is no operator to checktools before they are used, or check parts during the cycle. That’swhy consistency of toolsetting accuracy is critical.
As more automationis introduced into production, errors are far more costly. Through automation, the exact information about each tool can bemade available to the toolroom operator. A computer can generate thetool layout, indicating every dimension and shape. Then, two different toolsetting approaches can be used to ensureaccurate tool positioning.
First, the operator can set the tool exactlyas indicated by the layout, critically positioning the tool at thespecified zero points and checking its geometry in the process. An alternate approach can be quicker, but requires a moreintegrated, DNC-type network. By measuring the tool’s deviation from the specified zero point, then entering this data into thecomputer, the system can feed tool offsets directly to a CNC machine.It actually eliminates the toolsetting function, replacing it with tooloffsetting via the machine control. As a result, this approach limits tool accuracy to the accuracy ofthe machine’s offset system (control, encoders, slides, and ballscrews), but it completely eliminates the need for manual toolpresetting.
It’s ideal for turning applications where the tool isstationary, but less effective for rotating-tool setups. If there’s anything predictable about workpiece tolerances,it’s that they always get tighter. A good tool-control systemshould be able to accommodate future tolerance requirements as well astoday’s. Labor savings are the second important area where advanced toolroompractices pay off. Toolsetting remains one of the most labor-intensiveoperations in a modern metalworking system.
Accordingly, it stands togain the most from advances in automation. Toolroom automation canimprove worker output and reduce training requirements. First of all, the labor involved in toolsetting and control isexpanding with the increasing popularity of short runs. Here, toolsmust be set up or verified more often. Even if only a few parts arerun, the tooling must be retrieved from inventory, gaged, delivered tothe machine, and returned to inventory. As a result, it’s possible that more time is spent handlingand setting tools than running parts.
The flexibility and time savinggained through an investment in CNC equipment could be completelynegated by obsolete manual tool-control practices. The time savings offered by an automated toolroom can really addup, too. For example, if you have one full-time tooling operatorworking at capacity, an automated tool-management system can eliminatethe need for a second person as you get busier.
And, because thetoolroom operator can be prompted by the tool-control computer, lessspecialized training is required. Less experienced operators can follow the instructions on thescreen, and those with more experience can use the computer’sprompting as a reminder. In both cases, tool-setting personnel are moreproductive with computer-assisted toolsetting systems because allnecessary information is at their fingertips. Information management Management and manufacturing information control can both befavorably affected by automated tool-control practices. From amanufacturing standpoint, the tool computer helps guarantee the mostup-to-the-minute tool specifications without the need to revise layoutdrawings.
It can help monitor tool usage, compare tool life, and managetool inventories. Through a central computer, you can track tool usage and forecastwhen you will need to have certain tools delivered. When inventoriesdrop below a specified quantity, an order flag can be raised. Thishelps minimize tool inventories, yet assures timely replacement of spenttools. When comparing tool life, statistical analysis can eliminate thevariation associated with irregular tool wear.
The analysis showsunderlying tendencies that more accurately reflect typical tool-wearcharacteristics. As a result, you can evaluate the cost effectivenessof different cutting-tool options and make better selection decisions. From the product-design side of things, computer-aided toolsettingalso can improve responsiveness of manufacturing to part-design changes.Through an integrated CAD/CAM system, every design change can beimmediately reflected in tool changes. Whether new tools or differenttool settings are required, an automated tool-control system can respondequally fast. For shops of any size The concept of toolroom automation works on nearly any scale,whether you’ve got three NC machines or 300.
And benefits beginimmediately. In big shops, centralized tool control reduces inventory, labor,and cost of engineering changes. If computers are already used, acomputerized tool-control system can tie directly into them, painlessly.
Further, the toolsetting volume of a large shop can mean fast payback. For shops with as few as three NC machines, the same holds true.More small shops are using computerized programming systems that maketoolroom automation a natural.
Many computer-aided programming systems generate tool layout anddimension drawings electronically. Transferring this information to thetoolroom computer eliminates drawings and endless drawing revisions.One person can handle far more of the overall manufacturing-managementoperation. Such systems also can accommodate shop expansion. A modular systemlike Royal’s Variset gaging system lets you add capabilities asneeds develop.
System components Basically, there are four areas where automation can help thetoolroom: Toolsetting, tool storage, tool handling, and toolinformation. The requirements of each are simple. The toolsetting gage must be accurate, efficient, and impervious tohazards of the shop environment. An effective gage is the mostessential element of an efficient toolroom. The gaging system must have resolution greater than the closesttolerance measured.
Specifically, better than 0.0002″ for typicalmachining operations. (The better the tool-setting accuracy, the betterthe accuracy throughout the shop.) When comparing noncontact with contact gaging systems, noncontactsystems generally will result in better accuracy over the life of thegage.
They reduce the likelihood of problems caused by wear andcontaminants. Toolsetting gages that rely on mechanical contact canrequire more frequent mastering and adjustment. Whatever feedback system is used (glass scales, optical encoders,magnetic encodors, etc), it should be sealed against chips, oil, andcontamination.
Ideally, the entire gage should be protected from theenvironment. Some gages allow automatic positioning to the recommended tool zeropoint via servomotors. The computer-stored dimensions are relayed tothe gage, and it automatically moves to those coordinates. Thesesystems are efficient because the operator doesn’t have to manuallyposition the gage. Over the years, they will pay for themselves manytimes over in time savings. Storage, transfer, and control Effective tool storage is another important part of an automatedtoolroom.
Tool-storage systems must meet the same requirements as anystorage system: The tools must be protected, organized so you can findthem, and accessible to appropriate personnel. A variety oftool-storage systems meet these requirements with capabilities rangingfrom simple drawers and cabinets to fully computerized and automatedstorage and retrieval systems. Tool transfer is fairly easily automated with existing technology.
Tools must be transferred between the gage, storage system, machinetool, and the repair and sharpening area. The most basic tool-transfer system uses tool-handling modules thathold and organize several related tools. These same modules can simplify storage. With tools in place,modules can be transferred from storage to machine, either by hand, pushcart, conveyor, or automatic guided vehicle.
The more automation usedin tool transfer, the better control you’ll have over tools, andthe lower labor requirements will be. Tool-control systems are extremely important. Increased degrees ofautomation require more and more sophisticated control systems.Information and control needs will vary dramatically, based on your ownshop situation and requirements. For example, various printers andplotters can produce valuable management reports or tool-layoutdrawings, but they add to the overall cost of the system. Whatevercriteria are used to evaluate the toolroom control package, allow forsystem growth. Control communication capabilities are also important to allow thetoolroom control system to interact with other control systems andcomputers.
By linking to a host computer, CNCs, material-handling PCs,and plant-floor feedback devices, an automated toolroom has thepotential to become an integrated part of an entire manufacturingsystem. The concept of toolroom automation is fairly new, but the skillsand equipment required to implement it are available. The costs areinsignificant in light of the returns. Even a partially automatedtoolroom can pay for itself through improved control, reduced scrap, andmore effective use of existing personnel and tool inventories.
Forinformation on automated toolsetting equipment and systems, circle E66.