Machining large

Published
February 12,2019 - 12:45pm

Related Glossary Terms

  • boring

    boring

    Enlarging a hole that already has been drilled or cored. Generally, it is an operation of truing the previously drilled hole with a single-point, lathe-type tool. Boring is essentially internal turning, in that usually a single-point cutting tool forms the internal shape. Some tools are available with two cutting edges to balance cutting forces.

  • boring machine

    boring machine

    Similar to a turning machine except that the cutting tool (single-point or multiple-cutting-edge), rather than the workpiece, rotates to perform internal cuts. However, boring can be accomplished by holding the tool stationary and turning the workpiece. Takes a variety of vertical, slanted and horizontal forms, and has one or more spindles. Typically a large, powerful machine, it can readily hold tolerances to 0.0001". See jig boring; lathe; turning machine.

  • lathe

    lathe

    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.

  • 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.

Photo of Henri Liné Promill vertical boring machine by Alan Richter

One of the best parts of my job is visiting factories where metal parts are machined. In connection with the feature article I wrote for our April issue about machining large parts, I traveled to Romulus, Michigan, and visited Lincoln Park Boring Co., where I met with Vice President Gary C. Yesue and President Rick Yesue.

LPB’s 60,000-sq.-ft. shop is quite impressive, as well as being temperature controlled to ±1.5° F from the crane rail down. When it comes to machining enormous parts, LPB turns to its Henri Liné heavy-duty gantry Promill vertical boring machine with five-sided capability and 10' under the spindle (pictured). The travels for the X, Y and Z axes are 480", 204" and 120", respectively.

The company has some newer machine tools, such as a Fives Giddings & Lewis RT 130 horizontal boring mill with 5.1"-dia. spindle that it purchased last year, but I found some of the older machines to be equally if not more eye-catching. For example, one machine that grabbed my attention was a Monarch lathe (31" diameter × 60" travel) that was built in 1942 and still functions. I just appreciate how people designed products in the past, including old musical instruments, antique bicycles and muscle cars from the 1960s.

For the article, I also spoke with Norman Besand, shop superintendent for American Machine & Gear Inc., Portland, Oregon; Blake Conner, general manager for CBM Precision Parts, Bessemer City, North Carolina; and Michael Cope, product technical specialist for machine tool builder Hurco Cos. Inc., Indianapolis.

Author

Editor-at-large

Alan holds a bachelor’s degree in journalism from Southern Illinois University Carbondale. Including his 20 years at CTE, Alan has more than 30 years of trade journalism experience.