|”Brutus” is a 4,400-ton Verson tandem transfer press at Rockford Toolcraft. |
Activities in the aerospace, oil and gas, power generation, mining, and heavy equipment industries continue to drive demand for big machines to produce large, beefy, complex parts. Drive rolls made from stock material that weighs 30,000 lb, castings that measure 20 ft. by 40 ft. by 7 ft., stampings 60-in.- wide out of 0.500-in.-thick coil stock, and ball-valve housings with diameters between 11.81 ft. and 13.12 ft. are business as usual for shops that serve those megasized-parts industries.
D&M Precision in Oxnard, Calif., specializes in machining dies for the forging industry and parts for the communications, aircraft and aerospace industries. One of the parts the shop cuts for an aerospace customer is a drive roll made from a 30,000-lb piece of S4140. The shop machines it on a Viper VTL-20/24 from Mighty USA Inc. (www.mightyusa.com), taking a 0.22-in. depth of cut at a surface feedrate of 1.75 in.
According to Dan Lowe, owner and operator of D&M Precision, many of the metals machined at his shop are in the Rockwell hardness range of 38 HRC to 40 HRC, and require machine tools that are accurate and rugged. Most of the machines in Lowe’s shop are from Mighty USA and include three DM-100 bridge mills, a Viper VMC-2100 and the VTL-20/24.
|A drive roll at D&M Precision starts as a 30,000-lb piece of S4140. |
For the big stuff, the DM-100 full-range, bridge-type, vertical CNC machining centers feature rugged boxway constructions. They provide an ample working surface of 5.42 ft. by 6.69 ft. and easily handle workpieces weighing to 22,000 lb.
D&M Precision’s VMC-2100 vertical CNC sports large precision ballscrews with preloaded, ground, double nuts that are in the exact center of each axis. A fully ribbed column, bed and saddle support loads of 6,600 lb without table deflection. The machine’s work surface measures 6.89 ft. by 3.45 ft.
More than ever, processors within the mining, mineral and aggregates industries are cashing in on economies of scale by equipping their plants with huge grinding tables, roll crushers, kilns and material-handling systems in an effort to make big money off big demands.
Unfortunately, the gargantuan size of the respective parts – 26-ft.- diameter gears, for example – of these machines does not necessarily widen the margin of error when manufacturing them. If anything, flaws in castings or machining mistakes are magnified, so attention to detail and accuracy are just as important as they are with smaller parts.
Hodge Foundry in Greenville, Pa., a specialty-engineering foundry, manufactures high-quality complex gray and ductile iron castings that range in size from 3,000 lb to 200,000 lb. These castings can be for bearing bases, caps, gears, mill heads and trunions for cement and oregrinding equipment. Hodge Foundry is also one of two domestic foundries that make large hubs and bed frames for wind turbines. When it’s time to machine castings with dimensions of 20 ft. by 40 ft. by 7 ft., Hodge Foundry often turns to BVI Precision Materials in Allentown, Pa.
|BVI Precision Materials specializes in large part manufacturing for the power generation, mining, and cement industries. |
ASME certified in both pressure vessel and piping, BVI Precision Materials provides engineered, complete turnkey solutions for the infrastructure, power generation, mining, and cement industry sectors. These solutions encompass precision CNC machining and fabricating of gears, condensers, heat exchangers, kilns, mills, screens, crushers, dredges, conveyors, classifiers, cyclones, ducting and transition risers.
To machine its humongous parts, the shop incorporates such machines as a Maag model SH 600/735 gear cutter, a MAG Giddings & Lewis horizontal boring mill, and a Sellers vertical boring mill. The Maag gear cutter handles loads to 55 ton and gear diameters to 24 ft.
The Giddings & Lewis horizontal boring mill’s spindle travels 5.17 ft., its column 30 ft., and its vertical travel goes to 12 ft. On the Sellers vertical boring mill, the maximum table diameter measures 22 ft., maximum swing 28.5 ft., height under rail 12.5 ft., and ram travel 8.08 ft. The machine turns a maximum load of 93 ton at 4.6 rpm.
Rockford Toolcraft Inc. (www.rockfordtoolcraft.com) is another shop that doesn’t shy away from the big stuff. The firm designs and produces stamping dies and runs production metal stampings and assemblies. For these jobs, Rockford Toolcraft recently installed a 4,400-ton Verson tandem transfer press named “Brutus” that stamps heavygage parts made from coil stock as thick as 0.500-in. and 60-in. wide.
The Brutus press line is totally automated from coil entry to finished part. It has a bed area of 6 ft. by 27 ft.
A 60-person tool room with 10 skilled die designers supports the system, which is currently making heavy truck chassis cross members, but will be open for additional contract work.
The drive for large parts is not much different in other areas of the world.
Driven by a need for increased big-part machining capacity, Penztyazhpromarmatura, a Russian-based company, expects to take delivery of two large vertical turning lathes from Dorries Scharmann Technologie GmbH (DST). Each machine weighs around 220 ton and, when fully assembled, will measure 42.65 ft. by 47.57 ft. by 36.09 ft. and do the work of three or four conventional machining centers.
Penztyazhpromarmatura mainly produces valves for media such as gas, water, oil and chemicals in applications that include pipelines, power stations, chemical facilities and offshore installations. The company’s different parts – ball, flap, non-return, and gate valves – require turning, boring and milling operations in materials of cast metals, high and low alloy steels, and titanium. These parts are big. For example, housings for ball valves have diameters between 11.81 ft. and 13.12 ft.
The two DST machines, a Contumat VC 4000/350 MC V and a Contumat VC 3600/300 MC V, will allow Penztyazhpromarmatura to completely machine valves in single setups. As far as features are concerned, the two machines are identical, but vary in terms of machining diameters. One handles diameters to 13.12 ft., the other to 11.81 ft.