End Mill and Collet Combo Cuts High-Speed Machining Costs 62%

When SB Dezigns owner and CEO Billy Crabtree (left) decided to begin searching for tooling solutions to lower the cycle times on an automotive part in high-demand, he turned to W.C. Chapman sales representative Bill Anderson (right). Crabtree ultimately lowered costs for the operation by 62% and cut cycle times. Image courtesy of SB Dezigns.

Moving from a 25-part order to producing over 600 parts of one type every year is a leap, but one that Billy Crabtree, owner and CEO of SB Dezigns, was happy to make. His full-service precision production machine shop — which is also a tier-two automotive supplier — first produced a shifter for a customer in the racing industry several years ago, but the part has since become one of the customer’s hottest sellers. By 2019, demand had climbed to the point where Crabtree knew he needed to reduce cycle times to stay competitive and free up resources for other machining projects.

“It is very important that we keep evolving with the latest and best technology, and that includes cutting tools,” Crabtree says. “We were having excellent results with Emuge MultiTAPs, so we were all ears when Emuge and our local distributor W.C. Chapman suggested we try an Emuge-Franken end mill solution for the manufacture of the shifter parts.”

Stubbed Simplicity

Chapman representative Bill Anderson recommended the standard-length Top-Cut VAR End Mill with corner radius. Emuge manufactures these tools, which are a solid micro-grain carbide with a ALCR coating, at its North American headquarters in West Boylston, Mass. The company says its tool dampens vibration, increases feed rates and can be used with nearly all materials and milling strategies.

“With the Emuge-Franken end mills and holder combination, we are able to save over 30 hours of machining time and more than $5,000 for every 500 shifter parts we manufacture,” Crabtree says.

In spite of all this, Crabtree was initially hesitant to use the Top-Cut VAR — his shop used stub end mills on its high-speed machines, and the Top-Cut VAR was only offered as a full-length product at the time. Using only 3/8 to 1/2 of the standard-length flute struck him as a waste, but he agreed to a trial run with the end mill. The resulting productivity stunned him, and he swiftly asked if it was possible to obtain a stub version of the end mill. Emuge custom-manufactured several for him, and a company representative provided feed and speed advice.

Programming proved simple for the tools, with the shop’s Mastercam software able to import the Top-Cut VAR’s tool data from the web. Crabtree was able to adapt the data for his shop’s custom stub and before long, improved cycle times were making an impact.

Emuge caught Crabtree’s attention when it said the Top-Cut VAR End-Mill cuts as well as a five- or six-flute end-mill. Despite only being offered as a full-length end-mill at the time and not the stub variety SB Dezign used, Crabtree agreed to try it. The first run with the end-mill convinced him to order more in a custom stub variety. Image courtesy of Emuge-Franken.

Moving to the FPC Milling Chuck

Anderson also recommended its FPC milling chuck to SB Dezign, which had used ER collets up to that point. Emuge says its milling chuck offers increased rigidity, vibration damping, concentricity and pull-out protection via a pin-lock collet system. The company also says these benefits enable faster machining speeds and extend tool life.

Although Crabtree believed he was getting acceptable tool life with his ER collets, he agreed to try the FPC milling chuck. Now, he says “I’ll never go back to anything else.” He has transitioned his high-speed machining tooling to the Emuge chucks, only using the old collets for traditional drilling applications.

Savings and Cycle Times

The tooling changes proved successful for SB Dezign. “With the Emuge end mills and collet combination, we are able to save over 30 hours of machining time and more than $5,000 for every 500 shifter parts we manufacture,” Crabtree says. The end mills also last longer, providing 62% cost savings during manufacturing of the shifter parts.

SB Dezign has also begun using the Emuge combination for other jobs, such as those involving stainless steel and those for an electronics industry partner.