One aspect of the evolution of metrology in manufacturing can be shown with a clock and a pedometer. It wasn’t too long ago that part inspection typically meant taking a finished part to a distant room where the measurement equipment resided, which took a lot of time.
Over the years, metrology equipment makers have worked to reduce that distance in space and time between measurement and production. Knowing that anytime a CNC machine spindle isn’t turning means money lost, manufacturers have labored to allow necessary measurements to be made as close to the machine as possible. They’ve seen measurement equipment move from distant labs to nearer shop-floor-quality islands, then next to—and, finally, on or in—the machine making the part.
The Specto 3087 RC gage is for harsh-environment applications. Image courtesy of Heidenhain.
Integrating inspection with the parts-making process by integrating the respective equipment is a great time-saver, but it comes with a challenge: With chips flying and coolant spraying, the work envelope of a mill or lathe is not an ideal environment for the precision measuring equipment that was first developed for use in a controlled-environment laboratory.
Enter the Heidenhain Specto 3087 RC length gage, which increases productivity and efficiency, particularly in applications where, for reasons of time or accuracy, it isn’t possible to clamp the workpiece on a separate device to inspect it.
Instead, the gage integrates a highly accurate measuring process directly into the production process. The gage reportedly is optimally designed for measurement applications in the harsh production-type environment common to metalcutting. It has a high level of ingress protection (IP67) that allows parts to be measured directly at the grinding, cutting or forming location instead of transferring them to quality islands or laboratories. Eliminating the need for a part to travel that distance saves time and money.
The Specto 3087 RC gage has a special housing for in-process measurements. In the plunger-rest position, it houses the plunger and a rubber bellows surrounding the plunger, as well as a splash guard cap to close the exit opening for the plunger in the housing. For a measurement, which is normally made when the coolant is switched off, only the plunger and its bellows extend from the housing.
The optical scanning provides position values with a maximum error of ±1μm over a 30mm (1.18") measuring range. Thanks to its stroke of 30mm and its high accuracy over its entire measuring range, it can measure diverse components from the same fixture. In addition, the optical scanning with the ball guide permits consistent repeatability when scanning oblique surfaces. Cycle time for measurements is less than 1.5 seconds.
For more information about Heidenhain Corp., Schaumburg, Ill., visit www.heidenhain.us or call (847) 490-1191.
Related Glossary Terms
- computer numerical control ( CNC)
computer numerical control ( CNC)
Microprocessor-based controller dedicated to a machine tool that permits the creation or modification of parts. Programmed numerical control activates the machine’s servos and spindle drives and controls the various machining operations. See DNC, direct numerical control; NC, numerical control.
Fluid that reduces temperature buildup at the tool/workpiece interface during machining. Normally takes the form of a liquid such as soluble or chemical mixtures (semisynthetic, synthetic) but can be pressurized air or other gas. Because of water’s ability to absorb great quantities of heat, it is widely used as a coolant and vehicle for various cutting compounds, with the water-to-compound ratio varying with the machining task. See cutting fluid; semisynthetic cutting fluid; soluble-oil cutting fluid; synthetic cutting fluid.
Device, often made in-house, that holds a specific workpiece. See jig; modular fixturing.
Machining operation in which material is removed from the workpiece by a powered abrasive wheel, stone, belt, paste, sheet, compound, slurry, etc. Takes various forms: surface grinding (creates flat and/or squared surfaces); cylindrical grinding (for external cylindrical and tapered shapes, fillets, undercuts, etc.); centerless grinding; chamfering; thread and form grinding; tool and cutter grinding; offhand grinding; lapping and polishing (grinding with extremely fine grits to create ultrasmooth surfaces); honing; and disc grinding.
Turning machine capable of sawing, milling, grinding, gear-cutting, drilling, reaming, boring, threading, facing, chamfering, grooving, knurling, spinning, parting, necking, taper-cutting, and cam- and eccentric-cutting, as well as step- and straight-turning. Comes in a variety of forms, ranging from manual to semiautomatic to fully automatic, with major types being engine lathes, turning and contouring lathes, turret lathes and numerical-control lathes. The engine lathe consists of a headstock and spindle, tailstock, bed, carriage (complete with apron) and cross slides. Features include gear- (speed) and feed-selector levers, toolpost, compound rest, lead screw and reversing lead screw, threading dial and rapid-traverse lever. Special lathe types include through-the-spindle, camshaft and crankshaft, brake drum and rotor, spinning and gun-barrel machines. Toolroom and bench lathes are used for precision work; the former for tool-and-die work and similar tasks, the latter for small workpieces (instruments, watches), normally without a power feed. Models are typically designated according to their “swing,” or the largest-diameter workpiece that can be rotated; bed length, or the distance between centers; and horsepower generated. See turning machine.
- metalcutting ( material cutting)
metalcutting ( material cutting)
Any machining process used to part metal or other material or give a workpiece a new configuration. Conventionally applies to machining operations in which a cutting tool mechanically removes material in the form of chips; applies to any process in which metal or material is removed to create new shapes. See metalforming.
Science of measurement; the principles on which precision machining, quality control and inspection are based. See precision machining, measurement.
- milling machine ( mill)
milling machine ( mill)
Runs endmills and arbor-mounted milling cutters. Features include a head with a spindle that drives the cutters; a column, knee and table that provide motion in the three Cartesian axes; and a base that supports the components and houses the cutting-fluid pump and reservoir. The work is mounted on the table and fed into the rotating cutter or endmill to accomplish the milling steps; vertical milling machines also feed endmills into the work by means of a spindle-mounted quill. Models range from small manual machines to big bed-type and duplex mills. All take one of three basic forms: vertical, horizontal or convertible horizontal/vertical. Vertical machines may be knee-type (the table is mounted on a knee that can be elevated) or bed-type (the table is securely supported and only moves horizontally). In general, horizontal machines are bigger and more powerful, while vertical machines are lighter but more versatile and easier to set up and operate.
Workpiece is held in a chuck, mounted on a face plate or secured between centers and rotated while a cutting tool, normally a single-point tool, is fed into it along its periphery or across its end or face. Takes the form of straight turning (cutting along the periphery of the workpiece); taper turning (creating a taper); step turning (turning different-size diameters on the same work); chamfering (beveling an edge or shoulder); facing (cutting on an end); turning threads (usually external but can be internal); roughing (high-volume metal removal); and finishing (final light cuts). Performed on lathes, turning centers, chucking machines, automatic screw machines and similar machines.
- work envelope
Cube, sphere, cylinder or other physical space within which the cutting tool is capable of reaching.