Active in airborne atmospheric research since the 1960s, the Department of Atmospheric Science (DAS) at The University of Wyoming has a strategic mission to build expertise and recognition for the use of world-class observations and numerical simulations to address grand challenges in climate, high-impact weather, and air quality. At the cornerstone of the observational facilities, with field campaigns across the U.S. and internationally, is the King Air research aircraft, the third since DAS became operational.
Since 1977, the King Air’s evolving capability to support many different types of research instrumentation has been used in a wide range of studies, involving cloud physics, weather modification, air chemistry, and boundary layer studies, as well as serving as a platform for instrument development and testing. Now the current aircraft will be retired this year and replaced with a new King Air with new instruments and capabilities.
How do cutting tools help the research flight center? Machining is critical for readying the aircraft for its research missions, so enter end mills, taps, and toolholders.
With such important environmental research initiatives being performed, it made total sense that when Wade Dinius came onboard to establish the first CNC machining cell at the Donald L. Veal Flight Center in Laramie, Wyoming, supporting the DAS at The University of Wyoming, he instinctively turned to Emuge-Franken USA, West Boylston, Massachusetts, for its high-performance cutting tools and toolholders and history rich in innovation from its on-going, intensive R&D.
“While employed in the private aerospace industry, I was programming threaded holes with Emuge thread mills in notoriously difficult titanium forgings,” Dinius says. “Of all the suppliers, Emuge offered the best solution – threads were of perfect form and material removal rates were outstanding; I was impressed.” This experience led Dinius to reach out to Emuge to source taps, end mills, and tool holders.
Cutting tool demands
The machining operations in the new DAS CNC cell include emergent design, programming, and machining of the instrumentation and equipment required to perform aircraft-based and in situ atmospheric research in extremely demanding environmental conditions. Senior research scientists, flight operations staff, primary investigators, and university graduate students are all end users of the parts Dinius manufactures as part of the new CNC machining initiative. Federal Aviation Administration (FAA) scrutiny adds another level of demands.
Dinius explains, “Customer requirements are extremely demanding due to the nature of the unique and often irreplaceable instrumentation, as well as the fiscal constraints of grant-funded research. The economics of tool life and material removal rates take on entirely new meanings when you’re a non-profit organization, but the importance of our work makes finding solutions worthwhile.
“Deployment of the King Air often sees the aircraft loaded to maximum carrying capacity with research instrumentation, which makes the weight of the on-site fabricated parts and assemblies paramount,” Dinius continues. “As a result, thin-floor/thin-wall programming and machining is often required, presenting unique challenges dealing with cutting forces, temperature, and clamping stresses in order to mitigate part distortion.”
After reviewing application requirements and consulting with Emuge technical and product specialists, the DAS Flight Center has acquired more than 100 Emuge cutting tools and tool holders. Emuge has provided key solutions that extend tool life without sacrificing material removal rates.
A cloud droplet probe, along with several ports, had to be installed on the underside of the King Air aircraft, requiring a large plate of varying thicknesses engineered to withstand atmospheric pressure and load-bearing stresses. This was the first part ever programmed on the department’s new CNC mill, and Emuge FPC precision tool holders coupled with Top-Cut VAR high performance end mills produced a great part.
Featuring a chuck with a 1:16 worm gear, the Emuge FPC tool holder’s design delivers three tons of traction force. The design and body provide 100% holding power for maximum rigidity, and the collet-cone assembly absorbs vibration for maximum dampening. Top-Cut VAR end mills featuring unique geometry and coating offer a variable helix carbide solution effective in multiple job shop applications and in challenging production cutting operations.
“Layout inspection proved the Emuge FPC tool holder provides absolutely zero tool runout and perfect balance, and I’m confident we’ll see spindle preservation because of this,” Dinius says. “A truly balanced tool will distribute cutting forces equally across all flutes, extending tool life and improving surface finishes – I’m seeing the results of both of those dynamics in my finished parts,” Dinius adds.
The variable helix flutes on Top-Cut end mills and advanced ALCR PVD end mill coatings perform in higher operating temperatures, producing near-perfect parts.
“Emuge FPC collets are more robust and powerful than conventional ER collet systems I’ve programmed and machined with. Only having four extremely thin slots in the FPC collet allows for more contact between the collet and cutter, increasing the holding strength. Reduced slotting is also more successful in preventing the introduction of swarf and coolant upward into the toolholder assembly. After heavy use, I was shocked how clean the interior components were the first time I disassembled the Emuge FPC toolholder,” Dinius adds.
Aerospace professionals know threading aircraft fasteners in thin parts presents unique challenges. Class 3 fits and the ability to load transfer make thread form and depth critical. Emuge Softsynchro tap holders and Enorm Z-Taps meet these criteria and realize the full capacity of NC tapping.
Dinius says, “Aggressive spiral flutes and great lubricity are doing two things: eliminating all secondary operations associated with blind tapping, and also conserving our resources through extremely impressive tool life. A bonus is the extended shank of the Emuge taps, which is a programmer’s dream.”
A two-part construction physically separates the tap from the spindle via patented elastomer springs to let Emuge Softsynchro tap holders provide minimum tap length compensation necessary for exceptional tool life. Softsynchro brings out the full potential of the Enorm Z-Taps which have a very aggressive cutting geometry with elevated rake and relief angles suitable for a multitude of long-chipping materials.
“The Emuge cutting tools have exceeded all expectations and will facilitate the advanced machining of a wide range of materials associated with aerospace and instrument development for years to come,” Dinius concludes.