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Cost of Metal Removal Is Key
Part of This information was originally published by Manufacturing Engineering magazine and is reprinted here with the permission of the publisher.
The objective of both high- speed and high-efficiency machin- ing strategies is to improve MRR, according to Yair Bruhis, global product and application manager for YG-1 Tool Co., Vernon Hills, Illinois. High-efficiency machin- ing increases cutting by limiting air cutting time. “Because the two machining strategies are so effec- tive, people want to switch every- thing towards them,” said Bruhis. “But it all depends on the part and the machining parameters. Some- times, I can look at the part and state that it can’t be machined with high-efficiency strategies because of the shape and complexity of the part, or the machine’s capabilities, or the part features and program- ming, among other factors.
“I talk to a lot of people in aero- space and the trend has changed in the last 10 or 15 years,” Bruhis continued. “It’s not the cost of the tool anymore. Customers want to know the real cost of metal remov- al. There are a lot of cases where I meet with engineers or program- mers and they clearly voice that they do not care about the price of
the tool. Cycle time and tool life are the most impor- tant considerations.”
He also noted that the trend in titanium alloys and exotics machining in the last four or five years is toward high-speed machining for medium to large parts because the cost of removing titanium or Inco-
nel is much higher than that of aluminum or steel.
“In evaluating machining for large aerospace parts, for example, while I’m not a pro- grammer, in most cases I can look at the program and tell what ought to be changed,” said Bruhis. “In the last few years between traveling and working all over the world, if I can’t review the program, I have my customer send a vid- eo of the simulation and hold an online meeting to discuss possible program modifica- tions. Through Skype inter- actions, I do simulations and alter programs constantly.”
YG-1 has developed stan-
dard tools specifically for
high-speed machining of ti-
tanium, but about 30 percent
of its tools for this application
are still custom made, with
special lengths and corner
radii. “One of the trends with
high-speed machining is the
increased number of flutes
needed to take light cuts and
run very fast,” he said. “The
trend of the last five years is for five, six, seven and nine flutes,” he said. The advantage is longer tool life and better heat and chip control as well as machining performance.
“When major OEMs call me in, it’s generally to im- prove tool life, the process, or both,” Bruhis continued.
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