A gripping success
From early in his manufacturing career, Andreas Meier knew he wanted to start a machine shop. As the young entrepreneur made this dream a reality, he quickly realized that workholding would require significant attention.
MAJOR CHALLENGES FOR THE YOUNG COMPANY
The wide range of work tackled by a-m-z required flexible use of machines, which created a need for many different clamping devices, including two-, three- and four-jaw chucks. This created significant acquisition costs and frequently resulted in long setup and changeover times. Simultaneously, the company produced custom fixturing for everything not clamped in a chuck, resulting in additional costs. Early on, small order sizes made it difficult to achieve productive and profitable manufacturing.
The company also had difficulty with workpiece quality on some parts, as use of three-jaw chucks would lead to polygonal deformation. Yet with four-jaw chucks, the blank tolerances sometimes resulted in overcompensation. In the most extreme cases, this resulted in only two of the four chucks gripping the component. The unstable clamping conditions in those situations led to poor surface quality and uneconomic cutting conditions. At the same time, the use of compensating plates between the component and jaw resulting in lengthy changeover times that lowered productivity to unacceptable levels.
“Components were even ripped out of the chuck during machining”, explains Andreas Meier, “which caused substantial damage to some machines.”
GRIPPING THE WORKPIECES COULD NOT BE SATISFACTORILY SOLVED
Even with recurring part orders, individual runs were performed with completely different technology depending on the semi-manufactured part quality. The shop also had to maintain the flexibility to work with castings of aluminum, stainless steel, gun metal, brass, cast steel and cast iron, as well as steel flame-cut parts. This demanding environment created significant challenges for the employees operating the company’s mix of CNC lathes and 4-axis and 5-axis machining centers.
Things took a turn for the positive when Andreas Meier discovered the INOFlex® chuck when visiting the EMO in Hanover. This chuck solved the exact machining challenges that a-m-z had been facing, including variation in blank tolerances, flexible contours, gripping deformed inclines and flamed-out edges, and clamping deformation-sensitive components.
INOFlex® EXCELS IN COMPLEX CLAMPING OPERATIONS.
The first HWR product acquired by a-m-z was a 315-mm INOFlex®VK four-jaw power chuck. As soon as it went into operation, the company recognized substantial improvements. Because all jaws of the INOFlex® chuck grip with the same force regardless of the blank size or tolerances, cycle time dropped from 18 to 9 minutes for the first job processed with the new chuck. The reduced inclination to oscillations ensured improved surface quality despite higher cutting forces. Additionally, this component in particular was susceptible to deformation and the use of INOFlex® improved concentricity by a factor of 9.
CONSOLIDATING ON A SUPERIOR PRODUCT
Once the benefits of INOFlex® were evident, a-m-z ceased investing in two-jaw and three-jaw chucks. With INOFlex®, two-jaw gripping is possible without a chuck change and parts can be clamped with shorter setup times than with a three-jaw chuck. HWR’s compensating gripping chuck technology reduced the number of clamping jaws required, leading to lower equipment costs. As the benefits of the 315-mm chuck were realized, a-m-z also invested in the INOFlex® 210-mm chuck for the machining of small parts.
“If the INOFlex® chuck had been available ten years ago, I would no longer have any two, three or four-jaw chucks in the company and each lathe would be fitted out with INOFlex®”, states Andreas Meier.