Buffing wheels and equipment

BUFFING WHEELS AND EQUIPMENT by David d. Sax Stan Sax Corp., Detroit Three elements to a successful buffing operation are the buff wheel, the buffing compound, and the buffing machine. It is necessary to understand all of these elements and how they interact to achieve desired quality, productivity, cleanability, corrosion resistance, reject elimination, and overall cost-effectiveness.

WHAT iS BUFFING? Buffing is a mechanical technique used to bring a workpiece to final finish. It also can be used to prepare the surface of a machined, extruded, or die-cast part for plating, painting, or other surface treatment. The objective is to generate a smooth surface, free of lines and other surface defects. Buffing is not a process for removing a lot of metal. Deep lines and other more severe surface defects should be removed before buffing by polishing with a polishing wheel or abrasive belt. Buffing usually involves one, two, or three steps: cut buffing, intermediate cut, and color buffing. These operations normally are performed by what is referred to as either "area" buffing or "mush" buffing.

Cut Buffing A harder buff wheel and, generally, a more abrasive buffing compound, are used to start the buffing process. In cut buffing, the buff wheel and workpiece are usually rotated in opposite directions to remove polishing lines, forming marks, scratches, and other flaws.

Color Buffing When a mirror finish is specified, a color buff step may be required. Color buffing may be performed with a softer buff wheel and less aggressive abrasive compounds. In color buffing, the buff wheel and workpiece are usually rotated in the same direction. This enhances the cut buff surface and brings out the maximum luster of the product.

Area Buffing For localized finishing, narrow buffing wheels, positioned tangentially to the workpiece, are used. This is often is referred to as "area buffing,"

Mush Buffing To finish larger parts or parts having several surface elevations, mush buffing may be used. This involves the use of one or more wide buff wheels. In mush buffing, a part is rotated or caromed through the buffing wheel. This technique is also used to finish multiple products simultaneously. 51

BUFFING COMPOUNDS Buffing compounds are the abrasive agents that remove minor surface defects during the buffing phase of the finishing cycle. Buffing compounds are available in paste or solid form. There are thousands of products from which to choose. The prime consideration in selecting a buffing compound is the substrate being buffed and the surface to be provided. Nonferrous products made of copper, nickel, chromium, zinc, brass, aluminum, etc., frequently are buffed with compounds containing silica (generally amorphous, often "tripoli"). "Tripoli" is found in a small area of Oklahoma and is shipped all over the world. Steel products are normally buffed with compounds of fused aluminum oxide, which is available in DCF collector fines and as graded aluminum oxide in a range of grit designations. Special abrasives are available for other purposes. For example, chromium oxide is widely used to give stainless steel, chromium- and nickel-plated products high reflectivity. Iron oxides are used to color buff gold, silver, copper, and brass. Lime-based buffing compounds are used to generate mirror finishes on nickel products. Skilled buffing engineers can help manufacturers select the optimum equipment, buffing compounds, wheels, and buffing techniques. Cleaners and cleaning processes must be matched to the soil to be removed.

BUFFING WHEELS Fabrics used in buffing are designated by thread count and fabric weight. Count is measured by threads per inch; weight by the number of linear yards per pound of 40-inch-wide fabric. Heavier materials have fewer yards per pound. Lower thread count and lighter weight materials are used for softer metals, plastics, and final luster. More closely woven, heavier, and stiffer materials are used on harder metals for greater cut and surface defect removal. Stiffness is a result of heavier weight, higher thread count fabrics, more material, specialized treatments, sewing, and overall buff design. Buff wheel construction determines the action of the buff by making it harder or softer, usually by varying convolutions of the face of the wheel. This influences aggressiveness. Part configuration dictates buff design, construction, thread count, etc. Conventional buffs employ a circular disk of cloth cut from sheeting and sewn into a number of plies. For example, some materials require from 18 to 20 plies to make a lA-in.-thick section. Multiple sections are assembled on a spindle to build the required face width. The density of these types of buffs is also controlled by spacers that separate the plies of fabric or adjacent faces from one another. Industry standards for the inside diameter of airway-type buff wheels are 3, 5, 7, and 9 in. As a rule, productivity and buff wheel life increase as outside diameter increases and thread count and material content increases. Larger buffs and higher shaft rotation speeds also increase productivity and buff life. The choice of buff center size depends on how far the buff material can be worn before the surface speed reduces to a point of inefficiency, or flexibility declines to a point where contours cannot be followed. Airway buff flexibility decreases with use as wear progresses closer to the steel center. Most airway buffs are designed with as much material at the inside diameter as the outside diameter.

Flanges Buffing wheels require flanges for safe operation. Flanges must be sized for the specific inside diameter of each buffing wheel. It is important for all buffs that the flange be designed with sufficient strength to withstand the tremendous forces and pressures exerted in buffing. If buffs are not well designed and fabricated, centrifugal forces at higher speeds and the shock from operations can cause failure of clinching teeth, breakage of rings, and breakdown of buff sections. 52

Coating and Surface Treatment Systems for Metals by J. Edwards 470 pages $135.00 Selection of the most appropriate coating or other surface treatment is addressed in this comprehensive guide. Part I covers 76 industrially important coating types from acrylic polymers through zinc alloys. Part II provides an overview of the 19 most important coating and treatment methods with emphasis on the implications for a particular product in terms of its substrate or shape. Part III offers a guide to coating characteristics.

Send Orders to: M E T A L FINISHING 650 Avenue of the Americas New York, NY 10011 For faster service, call (21 2) 633-3199 or FAX your order to (21 2) 633-3140 All book orders must be prepaid. Please include $5.00 shipping and handling for delivery of each book via UPS in the U.S., $10.00 for each book shipped express to Canada; and $20.00 for each book shipped express to all other countries.

Table I. Commonly Used Buff Fabrics Warp (Lengthwise) 60 80 86 86 86

Filler (Crosswise)

Cloth Weight (Linear yd/lb of 40-in.-wide material)

60 80 80 80 80

3.15 3.15 2.50 (soft) 2.50 (firm) 2.50 (yellow treated at mill)

MUSLIN BUFFS The most commonly used fabrics for buffs are cotton muslins. As previously noted, fabrics are designated by thread count (e.g., 60/60, 80/80, 86/80). These designations refer to the threads per inch in the warp and fill, respectively. Fabric weights typically run from 2.5 to 3.5 yd/lb. (Table I).

OTHER BUFF MATERIALS Flannels Domet flannel (with nap on both sides) and Canton flannel (nap on one side and twill on the other side) in various weights are used where other fabrics fail to produce a high enough luster. Coloring of jewelry products is a typical application for such buff materials.

Sisal Sisal is a natural hemp fiber used for fast-cut buffing of steel and stainless steel. It is a coarse fiber twisted into strand groups and frequently woven into a fabric. It has a much lower thread count than cotton muslin, sometimes five by seven per inch, and offers the advantages of greater surface defect removal. Combination sisal/cloth buffs are effective designs (Fig. 1). The sisal plies frequently are cloth covered to omit the tendency of the sisal to cut the cotton threads of adjacent cloth plies. Alternating cloth and sisal improves compound retention, reduces unravelling, and moderates cut. Kraft paper alternated with sisal also has applications.

Other Natural Materials Occasionally, other materials are used to form buffs. For example, woven wool buffs are used on plastics, soft metals, and sterling silver. Sheepskin buffs are used to avoid surface drag or smear when buffing metals that contain lead. Russet (bark-tanned) sheepskin is used for cut. White alum (alum-tanned) sheepskin is used for color buffing.

Pieced Buffs Pieced buffs are less expensive because they are made of lower-cost materials. The buffs are made of colored segments, unbleached segments and occasionally bleached material.

Combination Buffs Often different materials are combined, especially sisal with cloth, and occasionally paper as well as cloths of different specifications. 54

ALL SISAL

SISAL W I T H CLOTH

SISAL W I T H PAPER

TREATED SISAL

Fig. 1. Sisal buffs.

Synthetic Fibers Unwoven nylon and other synthetics fibers, because of their water resistance, may be used wet or dry or with wax or grease lubricants. Buffs made of synthetics are ust/ally operated at slow speeds, typically 2,500 sfpm, to prevent melting and streaking surfaces.

BUFF TREATMENTS Treatments may be applied to fabrics (mill treatment) or to the buff after assembly (dip treatment). Buff fabrics are frequently hardened and stiffened to promote faster cutting, softened for additional flexibility to conform to contours, strengthened for longer buff life, or lubricated to prevent burning. Buff fabrics may also be treated to provide improved adhesion of buffing compound, to abrade for heavier cut, or to flameproof and make fire resistant. Treatments must be applied evenly and uniformly to avoid creating hard spots that cause uneven buffing. The treatment must not deteriorate with buff age. Unsuccessful treatments weaken the cloth and decrease buff life. 55

Fig. 2. Full disk

buff.

i

CONVENTIONAL, FULL-DISK BUFF DESIGNS Unsewn Buffs Conventional, full-disk buffs are made with die-cut cloth disks. Unsewn, conventional full-disk buffs may be used for luster (Fig. 2). Loose disks are turned to allow the threads of the material to lie in different directions. This results in more even wear, avoiding a square shape after being put into use. One disadvantage of this conventional design is that the fabric can fray or ravel. When held against a wheel rake, a cloud of threads may fly off. This shortens buff life, increases compound consumption, and adversely affects finish. Also available are solid bias sisal buffs, with every other layer being cloth, and rebuilt buffs made from reclaimed material.

Conventional Sewn Buffs Conventional, full-disk buffs for heavier buffing (cut) are sewn in various ways (Fig. 3). Closer sewing is specified for cutting harder metals and for removing deep imperfections. Concentric sewing causes a buff section to become harder as it wears closer to the sewing and softer after wear causes the sewing to break through. Spiral sewing results in more uniform density. Square sewing produces pockets that help the buff wheel to retain more buffing compound. Radial sewing, sometimes called suuray sewing, and radial arc sewing provide other variations. Tangent, parallel, ripple, zigzag, cantilever, and petal sewing are used for similar reasons. Special sewing, other than spiral, which is done on automatic machines, involves more labor in the buff manufacturing process, thus increasing the price per buff.

Folded or Pleated Buffs Folded buffs consist of circles of cloth folded twice to form a quarter circle, resulting in a "regular-pocket" buff (18 ply), or, for more cut, three times, to form eighths of a circle to constitute a denser "superpocket" (34 ply). The segments are laid down to form a circle, with each segment overlapping the previous segment. They are sewn around the arbor hole and partway to the periphery. The folds form pockets that hold compound and flex sufficiently for contour-following capacity. Folded buffs share three design deficiencies: lack of center ventilation, a tendency to fray, and waste of material in the unused center. 56

N

/

X'

)" /

"-

. f

CONCENTRIC SEWED

RADIAL SEWED

*ei

SQUARE SEWED

:/ \

\~'51 ;

SPIRAL SEWED

/

RADIAL ARC

R A D I A L ARC W I T H S P I R A L C E N T E R

Fig. 3. Sewn buffs. Pleated Buff Airway buff cloth may be accordion pleated to present more angles of material to the surface of the product to be finished. Pleating results in more cloth angles to reduce streaking and improve coloring characteristics. Better cutting is also achieved in some applications. Packed Buffs Buffs may be packed with spacers consisting of cloth or paper inserted between the larger diameter plies. The same spacer principle is used between buff sections. Both measures result in a softer wheel face. The packed buff construction is effective in contour buffing applications. A version of the packed buff, for threaded, tapered spindles (2-12-in. diameter), is used in the jewelry industry. The center is hardened, usually with shellac. The sides of the buff may be reinforced by leather disks.

Pieced Buffs Pieced buffs may be used in place of sewn full-disk buffs. They are made from remnants of cloth left over in the manufacture of other textile products. Such buffs require one of the types of sewing used for full disks in order to stay together in use. The chief virtue of pieced buffs is their higher value owing to the lower cost of materials. They usually are sold by the pound (see Table II). BIAS-TYPE BUFF WHEELS Bias buffs are more frequently used than conventional forms. They combine flexibility and cutting power. Bias buffs are cool running and resist burning. They are naturally ventilated. Side openings in flanges, center plates, and tabs, resulting in spacing between 57

Table II. Approximate Weight Table for Spiral Sewed Pieced Buffs REGULAR Approx. 1/4 in. Thick Diameter (in.)

HEAVY Approx. 5/16 in. Thick

EXTRA H E A V Y Approx. 3/8 in. Thick

Lbs. Per 100 Sections

Sections Per 100 Lbs.

Lbs. Per 100 Sections

SectionsPer 100 Lbs.

Lbs. Per 100 Sections

Sections Per 100 Lbs.

7.4 11.5 16.6 22.1 29.4 36.5 46.0 55.6 66.3 77.7 90.2 103.5 117.7 132.9 149.0 166.1 184.0 202.9 222.6 243.4 265.2

1351 870 602 452 340 274 217 180 151 129 lll 97 85 76 67 60 54 49 45 41 38

8.2 12.8 18.4 25.0 32.7 41.3 51.0 61.7 73.5 86.2 100.0 114.8 130.6 147.4 165.3 184.2 204.1 225.0 246.9 269.9 294.1

1220 781 543 400 306 242 196 162 136 116 100 87 77 68 60 51 49 44 40 37 34

11.1 17.3 24.9 33.0 44.1 54.8 69.0 83.4 99.5 116.6 135.3 155.3 176.6 199.4 223.5 249.0 276.0 304.4 333.9 365.1 397.8

900 578 401 303 227 182 145 119 100 86 74 64 57 50 45 40 36 33 29 27 25

4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

sections, enhance their cool-running characteristics. By using material cut on the bias, the threads form an "X" at the periphery of the buff. Threads are held at a 45 ° angle by cross-threads. This minimizes fraying and raveling (Fig. 4). Strips of bias-cut fabric are sewn into continuous rolls. After the rolls are cut to proper length, they are wrapped around a hub or core. They are then pulled to the desired inside diameter within the channel, usually by means of steel blades in an "Iris" machine. Straight-wound material wrapped around an oversized wheel results in a convoluted or "puckered" face; thus, the term "puckered" buff. The "puckered" face design of bias buffs tends to break up lines left in the surface of a product from previous operations. Increasing the size of the drums varies the amount of pucker in the face. The bias buff can be adapted to various contoured parts and degrees of cutting and coloring. An advantage of the "Iris"-made buff is the elimination of material beyond the inside diameter to the arbor hole. Thus, more of the cloth is available for use.

Ventilated Bias Buffs Although the puckered characteristic of bias buffs results in cooler running, some operating conditions require additional cooling. Steel centers with holes and ridges are designed to collect and divert more air. The air cools the buff and the workpiece surface. Clinch rings permit use of reusable metal inserts for substantial savings (Fig. 5).

PUCKERED BUFFS Puckered buffs are rated by numbers. Higher numbers indicate greater cloth content, buff density, and face convolutions (Fig. 6). Higher densities and closer convolutions increase cutting and reduce streaking. 58

Fig. 4. Bias buff (left) versus conventional buff (right). Thread configurations of bias buffs alternate warp and filler threads. Biasing provides design efficiency by exposing all thread ends to the surface being buffed, reducing fraying of the fabric.

Open-Face Cloth Buffs The open-face buff prevents loading, packing, clogging, and ridging during finishing operations. The plies are configured differently from the closed-face design. Buff material is wound singly or in groups of two, three, four, or more plies. Open-face buffs may be "straight wound" or "spiral wound" for a corkscrew or cross-cutting action that further minimizes streaking. Buff density varies with the number of plies, the amount of cloth, thread count, fabric weight, and treatment of the cloth. Buff pressure, speed, angle to the part, cloth strength, compound absorption ability, ventilation, and cloth flexibility are varied with buff design.

Fig. 5. Steel clinch ring (left) and steel clinch ring buff with open center (right). Buffs that are constructed by the clinch ring or "Iris" machine method have superior ventilation and cloth biasing, and optimal material utilization.

59

Fig. 6. Cloth bias buffs in order of increased density from closed face (left to right: O, 2, 4, 6) to open face (far righi) design. Bias Sisal Buffs "Iris" equipment used to gather cloth buffs is adapted to sisal and other materials (Figs. 7-10). Some bias sisal buffs are tapered (wider at the outside than the inside diameter). This reduces gaps between hard sections that could cause streaking. The tapered bias sisal buff is a long-life, cool-running buff for steel and stainless steel. Hard bias sisal buffs also are used in place of some belting operations, as well as in deburring and brushing.

Open-Cloth Bias Sisal Buff The open cloth bias sisal (OCBS) buff is used on contoured steel and stainless steel parts (Fig. 9). It consists of woven sisal and cloth, four plies of each (eight plies total), bound together by concentric sewing before Iris gathering. The buff is manufactured in endless strips, cut to length, rolled around split drums, and gathered into clinch rings by the "Iris" machine. A variation of the open-cloth bias sisal buff is the open double-cloth bias sisal (ODCBS) buff. This design consists of two layers of cloth sewn together with one layer of sisal to make a 12-ply buff of eight plies of cloth and four plies of sisal.

Spoke Unit, or Finger Buff Spoke unit or finger-type buffs combine great cutting power with the capacity to flex and accommodate contours and allow better workpiece coverage with fewer buffing heads. Spoke 60

Fig. 7. Conventional sisal buff.

Fig. 8. Bias sisal buff.

unit or finger-type buffs are made from materials that include soft cloth, stiff cloth, sisal, and coated abrasives. The material is manufactured into units, or fingers, sewn into endless belts, cut to length, wrapped around split drums, and gathered by an "Iris" machine into steel teeth. The spoke unit or finger sisal buff is usually made with woven sisal interlaced with 86/80 cloth. Acid or rope sisal is sometimes used. The cloth may be mill or dip treated (Fig. 10). The spoke or unit bias buff runs cooler than standard bias buffs and has a knee-action flexibility that gives superior contour-following ability. The width and number of the individual units is varied within limits. The range of buff density, or hardness, is varied by choice of materials, treatments, (buff center size) plies, and type of radial stitching. Some complex products are best finished with this type of buff.

Fig, 9. Open cloth sisal buff.

Fig. 10. Spoke unit or finger sisal buff.

61

~j

Fig. 11. Flap buff.

FLAP BUFFS The flap buff (Fig. 11) utilizes separate flap units placed at right angles to the direction of rotation of the wheel. Each flap supports the other to produce a smooth running wheel. Flap wheels were originally designed for bumper polishing and buffing operations. Flaps are made of coated abrasives, sisal, cloth and combinations thereof.

POLISHING WHEELS Polishing wheels are usually made of conventional cloth buff sections glued or cemented together. Canvas disks are cemented to the sides to protect the sewing. Glue or cement is applied to the face. Faces are struck with a pipe at angles and cross-angles to form a uniform crisscross of cracks on the polishing surface and provide sufficient resiliency to allow the wheel to make better contact with a workpiece. Buff sections used to make polishing wheels are generally spiral sewn and made of various types of cloth, sisal, canvas, or sheepskin. Solid, one-piece wool felt, and bull neck and walrus hide are occasionally used. Conventional straight buff sections that are glued together may cause streaking during polishing. An alternative involves inserting pie-shaped segments or other spacers between the buff sections to result in a "nonridge" polishing wheel that eliminates streaking. Various abrasive and adhesive combinations are used to grind, polish, and satin finish. These include liquid, graded aluminum oxide abrasives, greaseless compounds and burring bar compositions. 62

BUFFING EQUIPMENT Significant improvements have been made in buff wheels and buffing compounds to provide consistent and predictable performance. This has helped manufacturers of automated buffing machines to develop automated equipment for low- as well as high-volume requirements and to minimize labor and overhead in the finishing operation.

MACHINE DESIGN Mechanical buffing systems have a motor-driven shaft to which the buff wheel is applied. In addition, most machines will have a positioning mechanism, a finishing lathe, and workpiece-specifie fixtures.

Positioning Mechanism Automated buffing machines orient parts against the media by mechanical methods to duplicate or replace human motions. They rotate, oscillate, tilt, and index the wheel and/or the workpiece.

Finishing Lathe The finishing lathe is a device located in relation to the positioning mechanism. It allows a buff wheel to contact one of more surfaces of the workpiece at predetermined locations.

Fixturing The workpiece fixture or tooling is used to position a part during the buffing cycle. Buffing machines can incorporate single or multiple fixtures. Fixtures can also be designed to automatically reorient a workpiece during the buffing cycle. Buffing fixtures are unique to each part being processed, although some may be adapted to an assortment of similarly shaped parts. The design of fixtures is extremely important. Unless a part can be fixmred properly at a reasonable cost, the economical utilization of finishing equipment cannot be justified.

TYPES OF BUFFING MACHINES Buffing machines fall within three broad categories: manual, semiautomatic, and fully automated.

Manual Machines Manual buffing machines are used in low-volume applications and applications involving the buffing of extremely complex workpieces. Manual machines, when used in conjunction with the proper buff wheel and buffing compound, can be manipulated.

Semiautomatic Machines Semiautomatic buffing machines are used in lower volume applications where a single finishing operation is performed on a variety of parts. Initial investment and fixturing and operating costs are low. Semiautomatic finishing machines can be used with a single- or double-end lathe. One operator can be employed to load, unload, and operate equipment. Semiautomatic machines hold the workpiece and present it to the buff wheel. A timed cycle controls dwell and retraction. Only one fixture is required for each machine for each type of part finished. Because the machine supports the part, operator fatigue is minimized. Various types of rotation also can be performed, depending on the type of semiautomatic machine selected. 63

Production of semiautomatic buffing machines depends on part configuration and the degree of finishing required. By using a double-end jack with two semiautomatics, an operator can load one machine while the other is finishing a part. This can double production without increasing labor costs.

Fully Automatic Machines Fully automatic machines are used in high-volume applications and where multiple surfaces of a workpiece must be finished. The two most common types of automatic buffing machines are rotary automatic and straight-line machines.

Rotary Automatic Machines Rotary machines have round tables with finishing heads located around the periphery of the table. This type of machine is typically used to finish simple, round parts requiring high production. The number of finishing heads and production determine the size of the rotary. The table of the rotary machine can move continuously o1"index to start, stop, dwell, and then start again, with the length of the dwell controlled by a timer. The configuration and area of the product to be finished determine which is best. Production is higher on a continuous rotary machine because the table does not stop rotating. On an indexing rotary machine, because of the stop, dwell, and start cycle, production is lower. Parts that have surfaces that are difficult to reach and require more dwell time in certain areas may be finished on an indexing rotary machine to obtain the dwell time necessary. On each table there are rotating spindles on which the parts are fixtured for the finishing sequence. Rotary tables may have a greater number of fixtures than indexing tables, since the production and simple configuration make it more appropriate to be run on a continuous machine due to the ease of reaching all surfaces.

Straight Line Machines There are various types of straight-line automatic finishing machines. Normally, linear workpieces are finished on straight-line machines. Straight-line machines also can be used to f~nish round parts if extremely high production is required. There is less limitation on workpiece size as with rotary equipment. With straight-line automatic machines, finishing heads can be placed on both sides of the machine. In addition, various heads can be incorporated into the system for buffing and polishing. With rotary equipment, the outside periphery of a rotary table is used. Various types of straight line machines include: Horizontal return straight line Narrow universal straight line Over and under universal straight line Reciprocating straight line Open-center universal The size or length of these straight-line machines can be designed and built to accommodate the desired end result; floor space is the only major limitation. Each machine normally requires only one operator for load/unload. All operations of these machines are controlled from a push-button panel located near the operator for starting, stopping, and controlling various functions.

COMPUTER NUMERICAL CONTROL BUFFING MACHINES Buffing machine manufacturers can build equipment offering the same levels of control and flexibility available from computer numerical control (CNC) metal-cutting machines. 64

Separate CNC workcells can be designed to combine buffing with deburring operations within a given and limited series of process steps. It also is possible to integrate a complete sequence of manufacturing operations through a universal, plant-wide parts handling system to combine fabricating, machining, deburring, polishing, buffing, painting, plating, and packaging. Such systems have a significant impact on material handling costs, daily in-process inventory levels, direct labor costs, plant floor space requirements, safety, and overall productivity. CNC buffing systems offer a number of significant advantages. Equipment is programmed on the shop floor for reduced setup time. Buffing cycles can be reprogrammed to accommodate changing production requirements. Production data are automatically collected to support statistical process control requirements. Most important, quality is improved because part-to-part tolerances are consistent and repeatable. WORKPIECE HANDLING Significant advancements have been made in materials handling technology as it relates to buffing. A broad range of application-specific options is offered. These include pick-andplace workpiece load/unload systems, "blue steel" roller conveyor systems, lift-and-carry and shuttle-type in-line part transfer systems, trunnion-type transfer tables, power-and-free conveyor systems, robotic worktables, and automated guided vehicles for transferring parts between machines. SUPPORTING TECHNOLOGY Buffing systems are increasingly becoming turnkey, integrated installations. In addition to the basic machine, equipment builders can offer a variety of supporting systems to ensure increased performance and improved quality. Electronic options, beyond programmable controllers and computer numerical control systems, include the use of load torque controls, sensors, proximity switches, encoders, digital read-out devices, laser gauging, and LED programmable counters. Other supporting systems include quick-change and modular wheel assemblies, automatic tool compensation, automatic buffing compound application systems, dust collection systems, and automatic workpiece shuttle and load/unload systems. SUMMARY Effective buffing is accomplished through the proper selection of buffing compound, the buff wheel, and the buffing machine. In most instances, it is recommended that prototype or test parts be processed under production conditions to establish process parameters and prove production rates and quality.

65