Instead of a part breakdown causing a nearly two day outage, the equipment could be working again in about 14 hours
When the military needs a critical piece of equipment for a repair in-theater that isn’t readily available, the missing parts could jeopardize an important mission. To get the missing pieces, one traditional solution involves using strategically placed warehouses stocked with replacement gear. Another method is to pay a contractor to make a batch of parts on demand. There is a MITRE research project called MakeOne that would use 3D printing as its core, and which could cut days off getting critical parts to the field. Depending on its use, a part could be made to specifications that are “good enough” for temporary use, or made to more rigid specs for a permanent replacement.
The US military for more timely spare parts and the previously mentioned Airbus effort to develop the ability to print an airplane show that there are deep pocketed efforts to scale up additive manufacturing.
The other effort for large scale printing is the Caterpillar funding of concrete inkjet systems for constructing buildings. There are also european competitors in the print a building space.
A better idea is using a process called additive manufacturing—sometimes called 3D printing—to quickly make replacement parts. Additive manufacturing produces parts by building up layers of a part’s cross sections rather than removing material, as with conventional machining operation such as milling, boring, and drilling. A single additive manufacturing machine can produce an extremely wide range of parts—it just needs the computer-aided design (CAD) data to make any given part. Depending on the specific process and materials, the parts can be simple plastic objects, or intricate metal parts for cars and aircraft.
* a soldier or logistics officer at a strategic parts depot clicking a computer key to select a replacement part from a catalog displayed on a terminal. The soldier pulls a secure computer file for making the part from Materiel Command Headquarters in the United States and downloads it to a 3D printer close by. A plastic part is printed by a plastics-based printer, or a high-grade metal part is printed by a system using electron beam melting.
A part breaks in the field (1). A request for the part goes to the local parts depot (2). If none are on hand, the request goes to the Materiel Command (3). The secure parts database shows the part by model number or keyword and verifies that it’s correct (4). The file downloads to a 3D printer—either a plastic-based printer (5a) or a metal-based printer (5b), depending on the strength and application required for the part.
The team members have completed a catalog of machines and materials for additive manufacturing. They also created a semantic data model that includes materials, physical properties, test methods, modeling software, and how these things relate to one another. In addition, the team assembled three small machines from kits that are used for experimental work. MakeOne research will continue on a number of fronts, including standards development with ASTM, machine and material locations, logistics, and parts databases. The team’s next major thrust is to see what can be done with open source hardware. For fiscal year 2011, the Operation & Maintenance portion of the DoD’s total budget request comprises $283.1 billion.
Types of Additive Manufacturing
One form of additive manufacturing uses a machine similar to an ink jet printer. The printer deposits a layer of resin on a support table according to a computer-directed design. An ultraviolet light cures the resin into a thin solid layer about as thick as copy paper. Successive layers are added by lowering the support table and printing a new cross-section layer until the part is complete in three dimensions. Other types of additive manufacturing include:
* sintering—heating powdered metal below its melting point until it forms a solid mass
* melting— fusing particles together with heat
* spray deposition—building solid objects with layers of finely sprayed molten metal
* stereolithography—three-dimensional printing process that makes a solid object from a computer image by using a computer-controlled laser to draw the shape of the object onto the surface of liquid plastic
* lamination—bonding solid layers together as with plywood