Peter Zelinski has been a writer and editor for Modern Machine Shop for more than a decade. One of the aspects of this work that he enjoys the most is visiting machining facilities to learn about the manufacturing technology, systems and strategies they have adopted, and the successes they’ve realized as a result. Pete earned his degree in mechanical engineering from the University of Cincinnati, and he first learned about machining by running and programming machine tools in a metalworking laboratory within GE Aircraft Engines. Follow Pete on Twitter at Z_Axis_MMS.
Dual-column machining centers being produced at Okuma’s production facility in Kani, Japan.
According to machine tool distributor Gosiger, a dual-column or bridge-type machining center is 10 times more thermally stable than a comparable “C” style machine. Because of the dual-column design, says the company, heat affects the bridge structure linearly. The machine expands only in a straight line, allowing dimensional changes to be compensated electronically.
The dual-column design also places the spindle nearer to the center of mass of the machine, increasing rigidity. Read more in Gosiger’s article about dual-column machines.
Automotive knuckle photo courtesy of EOS and Rennteam Uni Stuttgart. Certain factors will enable additive manufacturing to be applied to an increasing number mass-production parts like this one.
In an interview with GE Capital, GE Global Research Center technology director Christine Furstoss was asked what factors will determine the speed of adoption of additive manufacturing into mass production applications. She described four.
Here is a paraphrase of her response. She says the enabling factors for additive manufacturing include:
1. Predictability. Manufacturers would benefit from software tools able to predict the outcomes of additive processes. GE is working with partners toward filling this gap.
2. Equipment. Mass production equipment has to not only achieve critical tolerances, but continue to hold them over time. GE is working with AM equipment suppliers by providing feedback on the machines’ performance with various materials over long periods of operation.
3. Materials. She anticipates a day when materials are not just adapted to additive manufacturing, but routinely developed specifically for additive processes.
4. Ecosystem. In addition to the makers and users of AM machines, there needs to be a more mature support system surrounding additive production. This includes companies supplying additive materials, as well as firms providing machine service and inspection services specifically related to AM.
A lot of the value in the way this part was machined can be found in the material that was left behind. The part is a 6.5-inch-thich blank for a fighter jet landing gear component. Sterling Edge Industrial Cutting of Denver, Colo. cut out this blank using an abrasive waterjet machine from Omax. If this rough machining had been performed through milling instead, then the material would be reduced to chips, and the value of the scrap material would be significantly less. Because of scrap value and other factors, adding waterjet to the process for a CNC milled part can add efficiency even if it adds an extra setup. Read more in the article, “Why Not Start with Waterjet?”
MC Machinery Systems, the Wood Dale, Illinois-based supplier of EDM machines, machining centers, press brakes, and laser and waterjet machines, has announced a partnership with Matsuura Machinery Corp. to introduce Matsuura’s Lumex Avance-25 additive manufacturing machine to the North American marketplace. The Lumex Avance-25 is a hybrid machine that not only builds parts through laser sintering, but also uses a milling spindle to perform precise CNC machining of the additively produced part within the same cycle.
MC Machinery Systems, wholly owned by Mitsubishi Corp., is well established in EDM machine sales to moldmakers. The company says this is why the partnership makes sense. Matsuura’s laser sintering hybrid machine was developed for making mold tooling, and it has been sold specifically in the die and mold industry in Japan and Asia.
“The moldmakers know us and know our people, and we’re excited to be able to offer them this innovative new technology,” says Nick Giannotte, MC Machinery VP for EDM, milling and waterjet.
Other applications present opportunities as well, the company says. MC Machinery and Matsuura see the machine also as a solution for medical implant production, and for enabling lighter-weight aircraft components. “All told, this machine will serve medical, automotive, aerospace, tool/die, and job shop industries,” a statement from the company says.
In difficult-to-machine metals, when a pocket or similar deep feature is milled in successively deeper Z-axis levels, oxidation and chemical reaction can affect the tool at the upper surface level of each cut. Early damage to the tool can, therefore, occur at this one spot. The tool might have to be changed because of the wear at this one spot, even though the rest of the tool’s flute length is sharp.
The solution: Change the axial depth of cut for each pass. This will distribute the problem area to different points along the tool, as the drawing above suggests.