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.
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.
According to 5ME, a recently discovered benefit of cryogenic machining is that it prevents the formation of an untempered martensitic “white layer” on the machined surface. This white layer is detrimental to aircraft parts because it encourages cracks. The discovery means that cryogenic machining can eliminate the acid bath usually used to remove this layer.
Cryogenic machining is the approach to tool cooling that delivers liquid nitrogen at -321°F through the machine’s spindle or turret and through the cutting tool. The supercooling reduces the rate of tool wear to such an extent that tool life and productivity increases can be obtained simultaneously.
5ME is the newly created company that is able to apply this technology to any builder’s machine tool. Read more here.
GE recently announced the winner of its Jet Engine Bracket Challenge. The challenge involved a bracket to be shifted from CNC machining to additive manufacturing. Machining limits design options, but additive manufacturing offers complexity for free. Therefore, GE’s challenge asked contestants to redesign the bracket to perform its function with the least amount of weight and material. The winning design is seen here. According to GE, M Arie Kurniawan, an engineer from Salatiga in Central Java, Indonesia, came in first out of nearly 700 entries from 56 countries. Mr. Kurniawan’s bracket and the rest of the top ten bracket designs were additively manufactured at GE Aviation’s additive manufacturing plant in Cincinnati, Ohio. Mr. Kurniawan’s design reduced the bracket’s weight by nearly 84 percent.
To illustrate our article about the commitment to training at Progressive Turnings, a Chicago-area job shop, photographer Todd Schuett of Creative Technology produced this composite image conveying the frequency with which plant manager Luke Niels conducts ad hoc coaching sessions on the shop floor.
The altered photo compresses several encounters into one scene, but in reality, of course, each of these encounters took a separate span of time out of the workday.
Mr. Niels can give this time freely and without consequence to himself, because he is a part-owner of the company. In other shops, establishing a culture of training is more difficult. The employee who gives time to teaching others will have less productive output to show for himself at the end of the day, and that may reflect poorly on him.
Does your shop have a system that protects employees against being subtly penalized because they direct some of their time and effort toward training others?
At the recent Euromold show in Germany, DMG Mori produced the part seen in this video to demonstrate the capabilities of its new hybrid machine, which is capable of both CNC machining and additive manufacturing through laser metal deposition. This video illustrates various capabilities of the machine, including the ability to use CNC machining to achieve tight tolerances on the additive part as it is being built, as well as the freedom to use the machine’s five-axis motion to additively build the part’s features in various different directions throughout the cycle. Sent straight from Euromold, this video is captioned in German but still easy to follow.