CASE STUDY: DEFENCE

Lockheed Martin 3D Prints a Large Prototype Fuel Tank

Lockheed Martin Space Systems Company designs, develops & manufactures high-tech systems for civil, defence & commercial applications.

In 2012 Lockheed Martin SSC were working on a new project to improve their satellite by optimising space to increase its payload capacity. One area that required a design change was the satellite’s fuel tanks the project would require many new parts to verify & validate prior to production sign off.

Before production sign off Lockheed would need to test & evaluate form, fit & function of fuel tank prototypes. Prototype parts produced using CNC machining would not be an option due to a tight deadline & cost restrictions. Traditional machining routes for making prototypes up to 2057 x 1158 x 1158mm would take 6 months & cost around £156,000. With the large format Stratasys Fortus 900mc Lockheed could use FDM technology for the prototype fuel tanks reducing both cost & lead time.

Lockheed Martin use a FDM bureau when they have a requirement for large thermoplastic parts or have limited in-house capacity especially robust & stable materials for form, fit & function testing. Due to the size of the tanks & the accuracy needed careful consideration was required on how the parts were oriented & what layer thickness would be best suited for the parts. The larger tank would have to be built in 10 sections & the smaller one built in 6 sections on a Fortus 900mc in polycarbonate material.

FDM fixtures were manufactured so that each part could be bonded accurately then brass inserts were added so that the tank could be assembled. The tanks were now ready for inspection & functional testing before moving on to the next design iteration.