End Mills Achieve Greater Depth of Cut in Aluminum
With so much happening in a busy show year between NPE2018 and Amerimold 2018, MoldMaking Technology is revisiting some of the technology that was on display. In case you missed it: At IMTS 2018: RobbJack has its FMHV two- and three-flute end mills, which are designed for high-horsepower, high-velocity aluminum aerospace machining.
RobbJack’s FMHV two- and three-flute end mills are designed for high-horsepower, high-velocity aluminum aerospace machining. The company says its Mirror edge geometry progressively reduces vibration at greater Z-depths of cut. Anti-pullout shank technology prevents tools from pulling out of the holder. Well-suited for high-speed machining of deep pockets and thin walls, the tools are available with through-coolant holes and a DLC coating that extends tool life in roughing applications. Overall length and reach length are designed to maximize gripping force in tight-tolerance toolholders. The company reports that a 1" diameter, three-flute FMHV with through-coolant holes and DLC coating can achieve a peak metal-removal rate of 713 ipm3 (72 lbs of 7075 aluminum per min.).
One of the most common methods of tapping in use today on CNC machines is 'rigid tapping' or 'synchronous feed tapping.' A rigid tapping cycle synchronizes the machine spindle rotation and feed to match a specific thread pitch. Since the feed into the hole is synchronized, in theory a solid holder without any tension-compression can be used.
Creating threaded holes in titanium alloys calls for proper techniques based on an understanding of both the properties of these materials and the peculiarities of the tapping process.
Running rotary milling cutters at the proper speeds and feeds is critical to obtaining long tool life and superior results, and a good place to start is with the manufacturer's recommendations. These formulas and tips provide useful guidelines.