3D printing is proving to be an important manufacturing technology within the defense sector. In the U.S. especially, resources are being allocated to explore the use of the technology for producing replacement parts on the fly, so that military equipment can be kept up and running. Recently, the Marine Corps Systems Command teamed up with fleet Marines and other organizations to investigate the performance of 3D printed impellers for M1A1 Abrams tanks.
Impellers play a critical role in the operation of tanks, as they help to remove dust from the tank’s engine, keeping the filters clean. If the part becomes damaged or suffers from wear, the impeller becomes less effective, as it pulls less air from the engine. The ability to 3D print impellers on demand could make it easier to temporarily replace out of commission impellers so that tanks have less downtime.
“Call it a spare tire or a stop-gap solution,” commented Joseph Burns, technical lead for MCSC’s Advanced Manufacturing Operations Cell. “This can get you through a mission, through your training exercise or whatever may be critical at the time.”
In this case, additive manufacturing could help to overcome existing logistical challenges faced by the military. For instance, a large order for impellers was placed by the Marine Corps and Army a few years ago, which resulted in the Defense Logistics Agency (DLA), which is responsible for providing replacement parts for military vehicles, did not have enough impellers to meet the demand.
“At certain times, logistical issues can occur,” explained Tony Delgado, research and development program manager for additive manufacturing at the DLA. “Sometimes the part is not available right away or something happens with a vendor and a part cannot be provided immediately. This was one of those times where the part wasn’t available.”
Before the adoption of 3D printing, the DLA would have had to order the large batch of parts from an external manufacturer, which could lead to long lead times of up to 10 months. Evidently, the lengthy turnarounds left much room for improvement. 3D printing, as it turned out, offered a viable solution.
“Around that time, the Marine Corps had been provided with 3D printing additive manufacturing tools,” said Burns. “And Marines were being encouraged to be innovative and develop prototype solutions to real-world problems. A young Marine identified the impeller and began exploring ways to 3D print this part.”
From there, the MCSC has teamed up with Johns Hopkins University’s Applied Physics Laboratory and the DLA to qualify the 3D printed impellers and establish standards for manufacturing the part. Recently, tests were conducted at Twentynine Palms, California, which confirmed the success of the 3D printed impellers for the Abrams tanks.
The testing consisted of using the 3D printed impellers in Abrams tanks for roughly 100 hours. After various exercises, the 3D printed components were analyzed for wear and tear or other problems, and none were found.
“Right now, we don’t see any reason why the 3D printed impeller is any less reliable than the OEM version,” added Burns. “We plan to continue to collect operational hours on three 3D printed impellers to better assess the long-term reliability of the part.”
Following the tests, MCSC is now working on a 100-page technical data package for the 3D printed impeller. The first finalized edition of the report is expected to be released in Q2 2019, marking the 3D printed impeller’s qualifications for Marine Corps use in Abrams tanks.
Presently, 3D printing is still a more expensive option than ordering batch parts from OEMs, but the time saved is a huge advantage. That is to say, 3D printing will not be used for large batch production for military applications just yet, but it will have an increasingly important role in the production of on-demand replacement parts. In the case of the tank impeller, 3D printing enabled a turnaround of under a week.
Other partners in the project include the Space and Naval Warfare Systems Center Pacific, 1st Marine Logistics Group, 1st Tank Battalion and the U.S. Army Tank Automotive Research, Development and Engineering Center.