CAD/CAM maximizes ROI

Edited by Elizabeth Engler Modic, Editorial Director - Manufacturing Group

Published December 09, 2016

From wing fittings to door structures to landing gear components, ADEX Machining LLC manufactures components for just about every part on an airplane. The company also manufactures similarly challenging components for defense and energy industry customers. While the work is rewarding, it poses challenges. Workpieces typically use hard-to-machine super alloys, have complex geometries, consider tolerances of 0.005" true position generous, and demand short delivery windows.

To meet these challenges, ADEX has enhanced its 5-axis CNC milling, vertical turning lathe (VTL), and EDM manufacturing capabilities by adding Mastercam CAD/CAM software from Tolland, Connecticut-based CNC Software Inc. This combination plays an integral role in ensuring delivery on its promises, even the ones that seem impossible to fulfill.

Charles Anthony, director of engineering and operations for ADEX says that his company’s strong relationships with customers come from delivering well-made parts at competitive costs while continually improving cycle times. One way to accomplish this is by systematically exploring the complete set of tools available in Mastercam and applying them to difficult problems.

One of ADEX’s challenging thin-walled parts starts out as a 25 lb block of Ti6AL-4V machined down to 1.15 lb with a minimum wall thickness of 0.041".

Space station docking system

When astronauts go to work on the International Space Station, the spacecraft attaches to a docking station that uses ADEX-manufactured spring arms to join the spacecraft to the docking station – allowing them to enter the human-friendly atmosphere.

Workpieces start out as 25 lb blocks of Ti6AL-4V that are machined down to 1.15 lb with a minimum wall thickness of 0.041". Each edge has a required radius and the material needs to be free of scratches, dings, and nicks, and can’t be buffed or sanded.

Programmers uses toolpaths incorporating Mastercam’s Dynamic Motion technology that intelligently alters cutting tool motion based on material conditions ahead of the tool to maintain an ideal chip load, reducing air cutting, and engaging the tool almost continuously with the material. This allows for higher cutting speeds with smaller carbide tools because the tool is continuously engaged and is being used along its entire flute length, reducing the incidence of breakage and stress to the material and machine.

Reaching as much as 4.5" into a thin-walled titanium part was a complex programming challenge that took the team about a month to finalize. They considered material type, cutting conditions, types of cutting tools used, and the coolant. They then used the software’s simulation features to identify mismatches, tweaking toolpaths to eliminate errors before the tool ever touched metal.

Heat resistant covers

Combustion covers start out as 950 lb forgings in 304 stainless steel that are whittled down to 700 lb. Tolerances include:

0.005" surface profiles
0.005" true position holes and bores
Required radius or chamfer on every edge
Zero mismatch on any cut surface

“We used everything in our CAM software tool box, from Dynamic toolpaths, Dynamic Lathe toolpaths, and C-axis toolpaths for the lathe, as well as Productivity+ in-process gaging to complete this project safely and efficiently,” Anthony says. “Active Reports allowed our team to document the application and results produced by the more than 300 toolpaths used for this project.”

Challenges involved programming extreme angles in some helix-bore cycles – tight holes that come in at angles and need to intersect pockets on the back side of the part. Due to its size, threaded holes were cut on the lathe and then the part was transferred to the 5-axis milling machine.

During initial milling, the multi-axis toolpaths appeared to be accurate; however, when the part was finished, it was consistently 0.010" off on the surface profile. ADEX found a slight amount of warping occurred after all the material had been removed during roughing.

Using Mastercam’s Productivity+ software module to intersperse spindle probe measurement sequences within the manufacturing program eliminates the need to dispatch quality personnel to the machine for in-process checks.

To combat this misalignment prior to finishing, engineers realigned the coordinate system to the centerline of the part, using a dial indicator – adding 2 hours to the cycle time for each part. That cost was unacceptable considering the manufacturer needs more than 2,000 covers for the more than 150 turbines each year.

ADEX programmers used Mastercam’s Productivity+ module for in-process gaging. This probing capability has been implemented on all of ADEX’s 5-axis machines, 3-axis mills, and the large VTL. In this case, it is used to probe the part at the beginning of the process for setup. The part is then roughed and probed again. If the part has slipped in its fixture, or if warpage is detected, the software uses data from the probing routine to automatically realign the part for finishing by reorienting the machine axis. The programmed change saved 1.5 hours per part using the probing capabilities.

The probing software used at ADEX was co-developed by the company and its Mastercam reseller, the latter of whom installed a post that included a substantial amount of programming and testing support from Mastercam’s Manufacturing Laboratory (machine shop). This customized version of Productivity+ allows the CAM programmer to create and call up the Mazak probing macros within Mastercam’s programming environment. At ADEX, up to 75% of the downtime associated with in-process gaging has been eliminated by the universal deployment of Productivity+ routines within Mastercam CNC programs.

Space station docking ring adaptor

The International Space Station docking system started out at more than 1,800 lb of proprietary aluminum that was machined to less than 45 lb. Each edge had a required radius, which included very precise profile tolerances along with being free of scratches, dings,and nicks and could not be buffed or sanded.

ADEX has worked on the docking ring adaptor that 15 countries throughout the world use to connect to the International Space Station. Made from proprietary aluminum, the tolerances on this adapter are 0.0833°, with surface profiles of 0.001", and all of the inside and outside surfaces have compound contours. Consisting of four individual pieces that must then be assembled together and put back on the machine for further finishing, the assembly measured approximately 60" in diameter, too big to manufacture on ADEX’s machinery, so the company partnered with an external shop for the final step.

The project took about a year-and-a-half to complete, but ADEX was asked to deliver the manufactured components in less than a month. Three upper assembly components were machined in roughly 12 hours each from blocks of aluminum weighing 350 lb to 400 lb. The large ring, into which these components were assembled, was cut from a 2.5" x 70" x 70" plate of a proprietary aluminum material. There could be no mismatches or any handwork. The ADEX team was given two weeks to develop a program to machine the final assembly using a large machine the team had never worked with before.

To expedite intensive manufacturing process development projects, ADEX relies on a customized version of Mastercam’s Active Reports to capture process knowledge.

“ADEX has about 350 toolpaths that it works with at any given time,” says Charles Anthony, director of engineering and operations at ADEX. “With the Active Reports, they are able to keep a detailed record of any job that comes through the shop, saving time with repeat jobs, and helping figure out the best way to approach new jobs.”

For the roughing work, the ADEX team used toolpaths incorporating Mastercam’s Dynamic Motion technology for high-speed machining of the heavy aluminum, maintaining consistent tool engagement with intricate compound contours. Mastercam simulation helped develop a program that would accurately machine the components to NASA specifications from a unique material. It also assured that a critical final machining process for the complete assembly would not alter the final assembly’s tight dimensions.

Not by chance

ADEX’s extensive use of the advanced capabilities of its CAM software is far from accidental. The company is in frequent two-way communication with both CNC Software and its local Mastercam reseller to better understand features that will give them additional productivity and cost reduction advantages, and to suggest improvements that could be made to further improve this advanced functionality.

“I see major improvements in the software. They are responsively eliminating bugs and creating new functionality that allows us to dramatically improve our productivity,” Anthony says. “Local support from our reseller, leveraging their own staff capabilities as well as Mastercam’s, is closing the loop to help us achieve our specific continuous improvement objectives.

At ADEX, up to 75% of the downtime associated with in-process gaging has been eliminated by the universal deployment of Productivity+ routines within Mastercam CNC programs.

“On top of that, ADEX makes sure that advantages obtainable via ongoing improvements in the CAM software are realized by conducting frequent training sessions with our manufacturing team in the shop. Nothing is left to chance.”

ADEX Machining LLC

www.adexmachining.com

CNC Software Inc. (Mastercam)

www.mastercam.com

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