Two of the essential characteristics of any successful machine shop are speed and accuracy, but depending on the application, they can be relative terms. At EWW Enterprise Inc., New Lenox, Illinois, speed and accuracy take on a multi-faceted meaning. According to Rich Schnautz, manufacturing manager, “A large portion of our work involves the machining of high-tolerance electrical components in multiple sizes and, generally, short runs. Because we are a critical link in our customers’ supply chain, it is essential that we be able to machine and deliver parts on short notice.”
Applications include parts for large industrial circuit breakers in a range of sizes, as well as bus bars, spacers and miscellaneous parts. Materials machined include 110 copper, aluminum and Delrin plastic.
Because of the large variety of parts called for and the varying dimensions involved, the term “speed” refers not just to optimized machining time but to changeover as well. “When it comes to rotational parts, fast changeover has to be accomplished without sacrificing accuracy,” said Schnautz. “And that can seem to be a contradiction in terms.”
Schnautz and EWW owner Ed Weiher found the solution to both problems by utilizing a SPANNTOP precision workholding system from Hainbuch America Corp., Germantown, Wis. The Hainbuch system replaces the conventional chuck, with the unit capable of fixturing collets in multiple sizes with a quick-change interface. Schnautz explained that the high precision offers several advantages. “In addition to enabling us to deliver high-tolerance components, the repeatability is so dependable that once the work offset is determined, resetting is unnecessary. Collets can be switched out quickly and easily even by less experienced operators.”
Added Weiher, “The SPANNTOP system allows us to use col-lets ranging from 4 to 65 mm. It is also equipped with Hainbuch’s Mando Adapt feature that enables us to quickly switch from OD to ID operations and is especially useful in machining pulleys and similar components. In fact, in many cases, it has enabled us to advance from multiple setups to only two operations.”
Recently, the reputation that EWW Enterprise has built for high-precision electrical parts resulted in an order from Fermilab, the national particle physics and accelerator laboratory based in Batavia, Illinois, for a key part for its particle accelerator. Machined from 110 copper, the part consisted of a concave “dish” about 2″ (51 mm) OD and 0.050″ (1.27 mm) center depth. Tolerance was 0.0005″ (0.013 mm), and the finish was critical.
“We made the parts on two machines, both of which are equipped with Hainbuch units,” explained Schnautz. “First, the part was turned on our Okuma Genos L3000-M lathe. We then used the Hainbuch Manok Plus stationary chuck to hold it in our Okuma MU4000V to mill the concave profile. The application represented a significant challenge for us, both in terms of programming and machining, and it’s extremely rewarding for us to know that our work is used in cutting-edge research technology.”
According to Tom Buraczewski, Hainbuch America regional sales manager, the rapid growth in the adoption of precision workholding systems, such as at EWW Enterprise, is primarily due to three factors: precision, fast changeover, and flexibility.
“At a time when part configurations are becoming increasingly more complex and the materials from which they are made are more exotic and expensive, inaccuracy is not something that can be tolerated,” he said. “The cost of time and materials is too great, and the setup procedure has to be on target every time. On machines equipped with conventional workholding devices, workpiece setup can take an extensive amount of time and, in some cases, require expensive fixturing. Precision workholding ensures that the correct tolerances are achieved on every part.”
The second advantage involves a fast change capability that applies not only to similar parts but, thanks to a wide range of collet sizes, to parts of different sizes and dimensions. “Shops with advanced manufacturing capabilities, such as EWW Enterprise, are frequently called on to deliver limited numbers of parts on short notice,” said Buraczewski. “The mechanical quick-change feature, coupled with a library of multiple collet sizes, makes this not only possible but relatively easy to accomplish. When it comes to non-standard sizes, our customers can special order collets tailored to their desired dimensions and fully equipped for our fast changeover feature.”
The third major advantage of Hainbuch’s precision workholding systems has to do with flexibility, he said. “Shops serving multiple clients involved in various industries, such as EWW Enterprise, understand the importance of versatility. At Hainbuch, the scope of our product line and the number and types of accessories that we provide deliver the capability to more easily accept challenges with widely differing characteristics.”
For example, the Mando Adapt feature speeds up both ID and OD machining without the use of steady rests or other cumbersome equipment. Hainbuch’s manual stationary Manok Plus chucks likewise allow for ID or three-jaw clamping and stabilize the workpiece through axial draw force applied against the end-stop. “As five-axis machining is fast becoming the industry standard, the Manok Plus offers both a precision production solution as well as an economical alternative to multiple fixtures,” Buraczewski said. “For example, EWW takes advantage of the ability to use the same components (collets) on both turning and stationary (milling) operations. This means the same clamping locations and datums are identical for both platforms (turning and milling),” said Buraczewski.
A further advantage, not immediately related to equipment operation, involves the ability of a precision workholding system to extend the life of an older machine through more accurate operation and to improve the quality of a less-expensive, entry-level machine through enhanced accuracy and dependability.
Said Weiher, “Although we provide an extensive line of metal-working services to a variety of customers, we take exceptional pride in the work we completed for Fermilab, which is emblematic of our commitment to using the best and latest technology available to meet our customers’ needs.”
For more information from Hainbuch America Corp., go to www.hainbuchamerica.com or phone 414-358-9550.