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FMS brings success to progressive job shop.

Jomico Metal Fabricators, a St Louis precision sheet-metal fabrication job shop, has found that an investment in flexible manufacturing has kept it one step ahead of its competition.

"In 1990, while our competitors were just beginning to implement punching machines," explains Thomas M Saputo, VP and general manager, "we had already installed CAD/CAM and three-axis laser cutting. Flexible manufacturing and robotics were the next logical steps."

In the same year, Jomico purchased one of the first five-axis robotic gantry systems with a high-speed spindle for trimming and profiling missile, aircraft, and commercial parts. Jomico's introduction to FMS was through Finn-Power International Inc, Schaumburg, IL. The Finn-Power system consisted of the TP-4020 hydraulic turret punch press with an integrated right-angle shear, load-unload, parts sorter, and parts stacker. The turret punch press is capable of punching 60" x 78" on a full 5 ft x 8 ft sheet without repositioning. Through 22 tool stations, and up to 11 auto-index stations, the TP 4020 offers flexibility with over 120 tools with Multi-Tool.

Designed with the F2 series hydraulic punching system, the TP-4020 delivers full tonnage throughout the stroke with hit rates of over 600/min. Electronic adjustment of the punch stroke depth for each tool is made via CNC control, and electric shimming means there is no need to shim punches after sharpening.

NC program controls punching-ram retraction height, and adjustment of stroke lengths results in optimum efficiency. Finn-Power's hydraulic system senses" a stuck punch and automatically re-hits the punch up to three times to free it from the sheet, eliminating downtime.

In addition to control of the punch stroke depth and length, the F2 hydraulics system provides for feed and speed control. With nine programmable punching speeds, the system can switch from a 600 hpm contouring move to a reduced, steady ram advance for forming louvers, shear tabs, and any other precise operation.

Another benefit of the Finn-Power FMS is the turret/right-angle shear combination that allows the sheet to be loaded, punched, sheared, and sorted automatically.

The integrated right-angle shear is operated by automatic subprograms and has two blades set at 90 deg that can shear a maximum 31.5" x 31.5" with one stroke. For longer pieces, a half-stroke is used in the X-axis direction for longitudinal cuts. The RS-804 has a maximum sheet thickness capacity of 8 gage with a stroke time of 60 spm. The sheared pieces from the right-angle shear can easily be sorted and stacked through the use of material-handling units.

"The ability to punch and shear on the same machine is a real advantage," says Mr Saputo. "Because you punch on the same machine and still hold the parts with the same clamps, Finn-Power offers an advantage in accuracy and maintaining closer tolerances."

Jomico reports an increase in productivity of 150% on one job alone using the flexible manufacturing system. And, in general, the system is running parts at half the cycle time that it would take on conventional technology.

For more information from Finn-Power, Schaumburg, IL, circle 318.

Spindle helps speed production

To keep up with increased production schedules for airplane seat tracks, Boeing Wichita Inc, Wichita, KS, needed additional equipment.

The firm purchased a Gicamill 19 vertical machining center, produced by Henri Line in Canada, equipped with an 18,000-rpm, high-speed, Model MFWS-1718, precision spindle from Fischer North America Inc, Weare, NH.

Boeing Wichita purchases about 50 different T-6 aluminum extrusions up to 400" long with an average cross section of 4" x 4"; the extrusions are machined into seat track configurations with more than 5000 individual part numbers.

In operation, the horizontal and vertical flanges of the seat track extrusions are routed to remove about 50% of the material to save weight. Lightening cuts at 100 ipm with the Fischer spindle remove metal quickly at tolerance levels averaging about 0.030". The Line machine also makes relief cuts perpendicular to the seat track length for the 1-beams which are positioned every 20" in the airframe. The Line seat track router, with 2400-rpm to 18,000-rpm spindle speeds, provides faster feedrates, smoother cuts, less vibration, and enhanced product quality. Feedrates have been increased about 15% over the old seat track router, allowing production averaging 7000 linear feet of seat track per week.

For more information from Fischer North America Inc, Weare, NH, circle 173.

Ballnose end mills cut machining time

KBA Motter, a manufacturer of large newspaper printing presses, switched to Carboloy's Minimaster milling system and cut machining time nearly 90%.

The problem facing the York, PA, company was machining a Class 40 cast-iron anti-lock bearing housing for one of its presses. The large, round housing needed 20 grooves totaling 50" (1270 mm) of milling. The job had been done on a 20-hp horizontal mill capable of 3300 rpm maximum. The trouble was that the job took more than half a day. The company was dealing with a cut 0.030" (0.762 mm) deep by 0.220" (5.6 mm) wide.

Before switching to the Minimaster system, Jeff Flaharty, general foreman of machine-shop services, used a 0.187" (9.35 mm) four-flute solid-carbide ballnose end mill. The machine ran at 1200 rpm, feeding at 4 ipm. Surface speed was 59 sfpm and the feed was 0.0008" (0.02 mm). At that rate it took four and a half hours to machine the bearing housing.

Tests by KBA Motter of the Minimaster system on the bearing housing produced dramatic results. By using a cutter with a diameter of 0.394" (10 mm) and a grade S60M insert, and cranking the horizontal mill's speed to its maximum, surface speed increased to 340 sfpm. Feedrate went to 40 ipm--a tenfold increase. The result was that the Minimaster plowed through the cast iron in 36 min.

The Minimaster milling system combines a reusable steel shank with a disposable carbide insert. Four different shanks--keyway, 90-deg, 87-deg, and 85-deg--of alternative designs cover a variety of tool-path operations. Insert styles include square shoulder mill, ballnose mill, chamfer mill, spot drills, and slotting inserts ranging from 0.394" to 0.630" (10 mm to 16 mm) in four steps. All Minimaster inserts are two flute, center cutting.

The replaceable carbide inserts are available in various diameters, geometries, and grades making the tool suitable for slotting, drilling, and copy milling. The uncoated grade S60M (P40 ISO classification) is intended for normal machining, and T60M with a PVD (physical vapor deposition) coating is recommended where wear resistance is a key factor.

Users can change the Minimaster from a slotter to a spot drill, or ballnose end mill and back again on the machine. The result is a savings in time and tooling because all that has to be done is to change the cutting edge. The carbide inserts can be used on a broad range of ferrous and nonferrous workpiece materials.

For more information from Carboloy Inc, Detroit, MI, circle 190.

In-place grinding improves quality

Until now, spindle taper problems usually meant pulling the spindle and sending it out for grinding. Southeastern Machining and Field Service Inc, Lancaster, OH, has developed an in-place spindle taper grinding service that offers an alternative to the extended downtime of replacing the spindle and bearing.

Provided the machine's bearings are in satisfactory condition, in-place grinding can be done on-site, requiring less than one day per spindle. This process can be used for the three major spindle taper problems that occur:

The first problem is machine malfunction or operator error. This can cause a toolholder to spin inside the spindle taper, leading to a buildup of galled material that reduces or eliminates contact of the tool with the taper surface. Though attempts to grind away the material buildup can increase taper contact, the increase is usually not sufficient for achieving satisfactory part quality levels. In addition, such grinding can irreparably damage an otherwise repairable spindle, rendering the machine almost inoperable.

A second spindle taper problem is bellmouthing. It takes place naturally as the spindle taper wears during continued production use. Bellmouthing occurs at the large diameter of the taper, leaving contact only at the small diameter portion, which may account for 50% or less of the total spindle taper area. This reduced contact leads to increased tool movement and greater tool runout.

Finally, weak tool retention can cause tool chatter even though the spindle taper is acceptable. Unchecked, the condition leads to premature taper wear. If tool retention is inadequate, the retention unit must either be adjusted or replaced to prevent taper problems.

In-place grinding has several advantages over spindle unit disassembly in correcting these problems. Because in-place grinding takes about one day per spindle, while the old approach can take up to four weeks, machine downtime is reduced to a minimum.

Second, the process doesn't require removal and disposal of spindle bearings which are in good condition.

Third, because spindle bearings are not disturbed during in-place grinding, there is no risk of calibration error between machines and bearings.

The fourth advantage is that once in-place grinding is complete and tool retention capability verified, the machine is ready to be set up for production. Machine alignments are not affected by in-place grinding and tolerances are held within new spindle specifications.

Finally, the process reduces both the time and cost associated with completely disassembling the unit.

For more information from Southeastern Machining and Field Service Inc, Lancaster, OH, circle 171.

Boring system speeds production

HAR Aerospace, Schiller Park, IL, recently replaced a time-consuming and costly jig boring operation in the production of its gear-carrier assemblies. By using a Command/URMA Micro-Max Boring System, HAR was able to machine the bores at the recommended speed without vibration.

The boring operations on the gear carrier assemblies consisted of two castings: one stainless, the other aluminum. The two parts had 14 bores with + or - 0.0005" tolerances, 12 with + or - 0.0003" tolerances, and 9 with + or - 0.0001" tolerances. Most of the bores had to be positioned within 0.0003".

The Command/URMA Micro-Max features an easily adjustable balance mechanism in the boring head. At HAR Aerospace, the operator adjusted the boring head quickly, for the bore size and material, to hold tolerance on all 135 parts in the part run. Standard inserts were used and worked well on both the stainless steel and aluminum castings, eliminating double setup time. In addition, the material was more efficiently sheared off, extending tool life. Scrap was eliminated, delivery time was reduced by keeping the job in-house, and production costs were cut by eliminating the jig grinding operation.

The Command/URMA Micro-Max System has additional features including cutting edge that can be rotated 360 deg, making it easy to turn tip away from the bore surface so that it doesn't leave a retraction groove after machining; coolant feeds through sealed passages that vent in proper position for cooling and lubricating cutting edge; tool shanks in CT, BT, HPMC, and NMTB designs. Tapers from 30 to 50 are available depending on flange style.

For more information from Command Corp, Minneapolis, MN, circle 172.

Spiral-fluted tap

makes blind holes Using a heavy-duty, spiral-fluted tap to machine blind holes in turbines, compressors, and reciprocating pumps, the Engine Process Compressor Division of Dresser-Rand, Painted Post, NY, has cut production costs and met stringent quality control demands.

Dresser-Rand, which serves the petroleum processing industry, switched to the Enorm-ST tap from Emuge Corp, Northborough, MA, after experiencing problems tapping blind holes with consistent sizes in its engine components. Inconsistent sizes caused rejection of the components, which had to be remachined, costing the company time and labor.

Machining operations at Dresser-Rand have since been simplified, reducing production costs and increasing productivity. "Before using the Enorm-ST, we bought taps based on a cost-per-tap basis," says Wayne Stickler, MRO buyer. "Now we buy them based on a cost-per-hole basis. This approach proves cost-effective in the long run because we get more holes per tap than with other models."

The Enorm-ST is manufactured from a proprietary formulation of premium cobalt high-speed steel. Heat treated to provide flexibility in the shank and rigidity in the tapping portion, the tap's short thread length reduces threading problems, while its spiral-fluted geometry provides optimum chip evacuation. It is available in sizes ranging from 0-80 UNF to 2" (M2 to M30).

Enorm-ST accommodates a variety of materials and a broad range of hardnesses including stainless steel, acid-resistant steel, alloyed steel castings, gray iron, and aluminum.

For information, circle 193.
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Title Annotation:Manufacturing Solutions; flexible manufacturing systems
Publication:Tooling & Production
Date:Jun 1, 1992
Words:2074
Previous Article:High-power lasers: bringing new applications to light.
Next Article:Probing for high-precision machining.
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