Boeing, Navy ManTech, NAVAIR AERMIP and Thermwood Collaborate on Large Scale Composite AM Cure Tool

Posted by Duane Marrett on Wed, Jun 30, 2021

Tags: Thermwood, Announcements, Large Scale, Thermwood LSAM, Navy, Composite Tooling, Boeing, Navair, Collaboration, Fleet Readiness Center

Thermwood was a key development partner in a Navy ManTech funded program issued to Boeing Research and Technology. The ManTech program was managed by Advanced Technology International (ATI) for the Office of Naval Research (ONR) with funding provided from the Naval Air Systems Command (NAVAIR) Aircraft Equipment Reliability & Maintainability Improvement Program (AERMIP). Fleet Readiness Center East (FRCE) was a key technical contributor for the low cost composite cure tooling technology development.

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Boeing, Navy ManTech, NAVAIR AERMIP and Thermwood Collaborate on Large Scale Composite AM Cure Tool

The Details

Thermwood’s Large Scale Additive Manufacturing (LSAM) machine was selected as the Large Format Additive Manufacturing (LFAM) machine to conduct the technology development. Several unique equipment features of the LSAM machine drove the selection. The high temperature autoclave cure tooling operating environment of 355 degree Fahrenheit and 85 psi provides a challenge for polymer based tool material. Additional composite cure tooling requirements for vacuum integrity and dimensional stability were validated during the development. Neil Graf Office of Naval Research, noted “Composite manufacturing is a strategic technology for future platforms and development of more cost effective tooling solutions would significantly benefit the implementation.”

The Process

FRCE provided a high contour mold line surface to Boeing for generating the composite cure tool. The mold line shape was very aggressive and would stretch the large format additive manufacturing technology processes capability. The spherically shaped portion of the mold line offered the largest challenge, as the unsupported 3D printed angle limitation of approximately 45 degrees provides an interesting obstacle to overcome for the spherical mold line section of the tool. Boeing rotated the 3D print plane 35 degrees to avoid encroachment of the build angle limitation.

Final 3D Print Model

Final 3D Print Model

The new innovative build plane approach eliminated the requirement for temporary support material for the aggressive mold line shape. The new build angle would test the LSAM machine limits in an area never explored previously. TechmerPM PESU CF 1810 high temperature print material was used for the composite cure tool. High temperature materials present additional challenges during print over low temperature materials such as ABS CF. Two interim support features were added to compensate for the center of gravity shift of the print. The LSAM machine performed flawlessly during the composite cure tool print. The tool was printed in 7 hours and 26 minutes using 610 lbs of material.

Composite Cure tool printing on Thermwood LSAM

Composite Cure Tool printing on Thermwood LSAM

The composite cure tool was machined in 53 hours using the LSAM gantry router machine. The tool datum features, and removal of interim members, were machined prior to removal from the bead-board. The Thermwood LSAM machine offers the ability to machine and 3D print on a single platform. The composite cure tool mold line part surface achieved at surface profile tolerance of .020” (+/-.010”).

Machining the Composite Cure Tool on Thermwood LSAM

Machining the Composite Cure Tool on Thermwood LSAM

The Boeing Research and Technology (BR&T) laboratory performed functional testing on the LFAM composite cure tool to ensure vacuum integrity and dimensional stability requirements were reached. The LFAM tool performed as expected and achieved all requirements. Several composite parts were fabricated from the tool. The tool durability was assessed during the multiple autoclave cure cycles and fabricated (3) composite parts. The tool maintained dimensional stability and vacuum integrity throughout the functional testing and composite part manufacturing.

LFAM tool after Autoclave Cure

LFAM tool after Autoclave Cure

The composite cure tool was printed and NC machined on Thermwood’s Large Scale Additive Manufacturing (LSAM) 1020 machine. The LFAM technology cost savings was estimated at 50% compared to traditional tool fabrication methods, and reduced tool fabrication lead-time by 65%. The cost savings and tool fabrication cycle time reduction could provide enormous benefit to any organizations performing low volume or custom composite part fabrication and repair.

Composite Part Fabricated from LFAM Tool

Composite part fabricated from LFAM tool

Nondestructive Inspection (NDI) was performed on the composite parts fabricated on LSAM tools. The NDI results did not indicate any porosity. Due to the complex shape of the composite demonstration part several NDI process were employed. X-ray and C-Scan results did not reveal any delaminations or defects.

The Bottom Line

The program benefited from a cooperative effort among several contributors to achieve success. The partnership between industrial technology leaders, Boeing and Thermwood coupled with the Office of Naval Research’s drive to transition technology, led to the successful program. “Collaborations such as this help expand the scope of capabilities of emerging large scale additive technology by addressing real world challenges that would be difficult for any single entity to define and address by itself. We look forward to new challenges moving forward”, says Thermwood CEO, Ken Susnjara.

Additional development is key to expand LFAM composite cure tooling implementation. Boeing Associate Technical Fellow Michael Matlack commented “The program provided significant results in validating additive manufacturing as a viable method of producing lower cost, capable tooling with substantial time savings over traditional methods.”

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Polysulfone Offers Promise for 3D Printed Composite Tooling

Posted by Duane Marrett on Thu, Oct 19, 2017

Tags: Thermwood, Announcements, 3D printing, Additive, LSAM, 3D Print, Additive Manufacturing, PSU, Polysulfone, Composite Tooling

A cooperative effort between Thermwood Corporation, Applied Composite Engineering (ACE), Techmer PM and Purdue University’s Composites Manufacturing and Simulation Center has produced a composite helicopter part using a 3D Printed Polysulfone (PSU) mold.

PSU mold printed and machined on a Thermwood 10'x20' LSAM®

PSU mold printed and machined on a Thermwood 10'x20' LSAM®

Final Part from mold (oil drip pan for a Chinook Helicopter)

Final Part from mold (oil drip pan for a Chinook Helicopter)

The Details

The mold was printed from Techmer supplied carbon fiber reinforced material and trimmed on Thermwood’s Large Scale Additive Manufacturing (LSAM®) machine. ACE produced a production part from the tool in an autoclave using normal production processes.

Despite the fact that Polysulfone appears to be an ideal material for this application, the participants believe this is the first time PSU has been 3D printed, since it processes at temperatures and requires torque levels above those needed for normal polymer extrusion.  The extruder and print head on Thermwood's LSAM machine has been specially designed for ultra-high temperature, high-torque operation.

3D Printing Mold on Thermwood 10'x20' LSAM®

3D Printing Mold on Thermwood 10'x20' LSAM®

The part, an oil drip pan for a Chinook Helicopter, was molded in an autoclave at 275oF and 90 PSI. The printed mold held vacuum without the need for special coatings other than normal mold prep and release. With a Tg (glass transition temperature) of 372oF the participants believe that this particular PSU formulation may be able to process parts at up to 350oF which is adequate for about 95% of composite parts processed today. Additional tests will be performed to determine the suitability and durability of this material at this temperature. They also plan to evaluate Polyethersulfone (PES) which processes and operates at even higher temperatures.

The PSU mold and resulting part were displayed at the recent AM2017 Additive Manufacturing Conference in Knoxville.

Comparison vs Traditional Methods

Another interesting aspect of this collaborative effort is that a mold for the same part was built by ACE using traditional methods and the cost and build time was compared to making the same tool using additive manufacturing. The results were stunning.

The Results

Additive manufacturing material cost was 34% less and it required 69% fewer labor hours. Build time for the additive tool was 3 days versus 8 days for the conventional tool. If the part was larger, a support structure would be needed for the conventional tool which would add two days and more labor hours to the conventional process. A larger additive tool would not require a support structure.

The goal of this collaborative effort is to develop materials and processes to efficiently and reliably 3D print production composite tooling, capable of operating at elevated temperatures in an autoclave. These first successful results may indicate that they are very near reaching that goal.

Collaborative partners on this project

Applied Composites Engineering – Composites is their business focusing on aerospace. With nearly thirty years in the industry they have shown core competency rarely found in a company their size. This combination of capability and experience provides their customers with the benefits of a larger company supporting more sophisticated projects and larger production along with the speed and flexibility of a smaller enterprise.  

Purdue’s Composites Manufacturing and Simulation Center – Their primary focus among others is to develop a comprehensive set of simulation tools that connect composites from their birth in manufacturing to predicting their useful life. They predict and measure the anisotropic deformation that occurs in printed elements, including a description of anisotropic element shape change during deposition in order to anticipate performance of the printed element.

Thermwood Corporation – Pioneer in CNC development, first company to build and sell a CNC router has moved aggressively into developing and building large scale additive manufacturing systems and industry leading software. Its LSAM (L-Sam) system prints and trims large to very large molds and tools that are solid, virtually void free and able to sustain vacuum without secondary coatings.

Techmer PM - A leading manufacturer of high-performance custom compounds used in the plastics industry, they seek to deliver value-added, breakthrough solutions to the OEM and processing communities worldwide. Working extensively with the additive manufacturing community they have developed materials ideally suited to the additive manufacturing process and have wide-ranging experience with additive manufacturing technology.

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