When Bigger Really is Better

At the onset of business with their now key machine tool supplier, R-Tech Tool & Machine (Wamego, KS) kicked off the relationship in a completely opposite way that most other shops would have done. Instead of a conservative start with maybe smaller, more moderately priced technology, they purchased, in the words of their president Doug Routh, “the biggest and baddest machine” the supplier offered, then worked their way down to eventually acquire several other standard-size pieces of equipment. This unconventional strategy is one that has worked extremely well for a 25-year-old shop that has grown into one of the most dependable machined-parts suppliers to a heavy equipment OEM. In fact, R-Tech is located so close to this major manufacturer of construction and mining equipment that both parties benefit in terms of logistics, delivery times and cost effectiveness.,

The big machine that spurred major growth for R-Tech was a huge Versatech V-140N double-column bridge mill from Mazak Corporation (Florence, KY) with twin-table changing and multiple machine heads for its spindle. This bridge mill then gave way to the installation of two HCN-6000 horizontal machining centers inside a fully automated Palletech 32-pallet flexible manufacturing system (FMS), individual Integrex i-200 and Integrex e-420H full 5-axis turning centers and, most recently, a small-footprint Quick Turn 200M turning center with milling capability. Routh has never regretted his decision to go big first with the shop’s machine tools, because the Versatech V-140N gives them a competitive advantage and has even helped win them new work. “We can always do smaller parts on a big machine if need be, but we don’t have the option to cut big parts on small machines,” noted Routh. “That being said, our bigger machines have also become the backup plan for our smaller work. We can set up the bridge mill, for instance, with multiple smaller parts on both of its tables, and it will run them all unattended.”

The double-column bridge mill currently makes R-Tech one of the only shops in the area with such large part machining capacity. It also cuts all of their part-welding fixtures, which are naturally bigger in size than the large parts they hold for welding. The Versatech V-140N has machined parts measuring 12 ft wide by 20 ft long by 6 ft tall and cut all five sides of them. Its two-table changing capability makes setup time inconsequential. While the machine works uninterrupted on one table full of parts, operators can either load or unload the second table that’s outside the machining area. With a spindle head that positions vertically, horizontally and at any angle in between, this bridge mill delivers unsurpassed performance and productivity in machining very large workpieces. The head performs 5-axis multi-face machining in single setups to significantly reduce large-part handling and repositioning while also boosting cutting accuracy. “Customers do not pay for set up time,” smiled Routh. “You must do everything in your power to either accomplish set up as quickly as possible or remove it from the equation all together.”

Most parts done on the Versatech V-140N involve long tool reaches and deep bores with numerous obstructions, and such features make it difficult to do the parts on conventional HMCs. “We once got by with an old manual horizontal boring mill,” recalled Routh. “But to maintain our cost competitiveness, we had to do better in terms of setup times and machine output.” When it comes to increased output, the Palletech system with the two HCN-6000 HMCs eliminated the need for six older different brand HMCs in the shop. The automated system also significantly boosted the productivity of the existing workforce so that instead of six guys running one machine each, three of them now oversee the cell while the other three are able to run other machines.

For fast and precise axis positioning, each HCN-6000 rapid traverses at 2,362 ipm per axis and accelerates/decelerates at 0.7 G, while smooth high-gain servo and high-power AC servomotors provide vibration-free, accurate axis movement. Two-pallet changing capability is standard with these machines, which are pre-engineered to seamlessly interface with the Palletech system. Within the FMS, a rail-guided robot loads and unloads the machine tools to keep them running unattended and lights out overnight. “When it comes to lights out operations, the tool life management software has proven key to getting most unattended operation from our bridge mill and the HMCs in the FMS,” said Routh. One HCN 6000 has 120-tool storage, while the other accommodate 180 tools. Few of the shop’s jobs allow for redundant tooling, so when running as many as eight to ten different part number jobs overnight, the cell can on occasionally run through all of the tooling. But when the job mix is right, the cell easily runs all night.

Whenever possible, the shop will rough out parts overnight in the Palletech system, then finish them on the 5-axis Integrex i-200 and e-420H machines. Both machines combine the abilities of a high powered turning center and full function machining center to productively turn, mill, bore and drill, while offering 5-axis simultaneous machining. Each machine sports a main turning spindle and vertically-mounted milling spindle with rotating B-axis. All of this provides the shop with Done-In-One® processing capability for their more complex work, such as internal components for industrial pneumatic hammers that involve extremely tight tolerances and a lot of metal removal. For example, a wear-sleeve component has bore diameter and cylindricity requirements that both must be held to within ±0.0004 in. With the shop’s weldments, material removal is minimal but their sheer size presents the real challenge when it comes to machining.

With milling capability in its tool turret, the Quick Turn 200M turning center gives the shop multi-tasking capability for relatively smaller parts. For example, the machine cuts a lot of the carrier components that mount to the hammer wear sleeves and, according to Routh, the somewhat smaller parts are equally as intricate and complex to machine as the sleeves themselves.

Routh started R-Tech with one NC lathe and an NC mill, but has since grown to fill three buildings. His wife, daughter and three sons are all now involved with the business: oldest son Josh handles purchasing, twin sons Jordon and Jacob are both machine shop foremen, daughter Chantel is the office manager and wife Rachelle is part owner and vice president. The shop currently employs 60 people, and Routh expects that amount to grow by 10 or 15 in the very near future. In addition to their heavy equipment work, R-Tech produces components for amusement park rides, power plants, railroad locomotives and rail cars, as well as for architectural structures. Most of the shop’s work involves hot-rolled abrasion-resistant steel and large weldments. Most parts start as raw steel plates that are burned, bent/formed, welded and machined, then painted. Some begin as bar stock, while others are castings that can weigh anywhere from 5,000 lb to 40,000 lb with tolerances as tight as ±0.0004 in on 2.500 in diameter bores that are 12 in deep.

“We try to stay in the medium-to-big part size/weldment range,” explained Routh. “For us, medium parts are those that weigh 1,000 lb or more. The really large ones are those that can weigh upwards of 43,000 lb. This kind of capacity and machining capability gives us a niche that most shops are unable to compete against. And big part machining tends to stay on this side of the pond because of logistics costs, which also works in our favor.”

R-Tech Tool & Machine, 403 Miller Drive, PO Box 293, Wamego, KS 66547, 785-456-9541, Fax: 785-456-9546, [email protected], www.rtechtool.com.