Earlier this month I had the opportunity to speak at the Defense Materials, Manufacturing and Infrastructure (DMMI) Committee’s workshop on Low Volume Manufacturing at the National Academies in Washington DC. The purpose of the committee is to provide support to the defense industry on various topics of interest. Reducing costs and lead times is always a priority, but with the recent Sequestration budget cuts it has become an especially hot topic in the defense industry where low volume manufacturing is prevalent. I previously wrote an article on low volume manufacturing in the medical industry and was invited to share my experiences at the workshop so they could get an outside perspective.
While I think they really appreciated and took away a lot from our experiences in the medical industry, I also learned a few things as well. A member of GE Aviation was talking about how they have been testing using 3D Printing/Additive Manufacturing for certain parts in their jet engines over the last few years. Currently they make their fuel injectors by welding together up to 20 machined and casted parts to get the optimal air and fuel flow geometry. This is a very labor intensive process and machining the expensive materials required to withstand jet engine temperatures results in a lot of wasted high cost material. By using laser sintering they are able to make injectors in less time that are lighter and perform better with no expensive wasted material. Within the next three years they expect these “3D Printed” parts to be implemented in their engines with cost savings of up to $25,000 per engine.
Another member of the committee who works for the Army talked about how they are using a similar metal laser sintering technology to create mold inserts for injection molded parts. Traditionally molds are machined from a solid block of material by milling or EDM. By using the additive laser sintering process they are able to build the molds much faster and cheaper, especially when the molded part is very complex. Additionally, features like gates, cooling lines and venting can be built directly into the mold insert which can further save on time and cost. While injection molding is currently used more for higher volume parts, the reduction in the cost of tooling from laser sintering molds could make it much more feasible for lower volume parts than it has been in the past.
Here at Key Tech we use similar types of additive manufacturing processes for rapid prototyping parts before production. For the most part though cost and material issues have kept us from using them for production parts. However, based on my experiences at this workshop it sounds like additive manufacturing technologies are continuing to improve making them viable for more than just rapid prototyping. Who knows, maybe we’ll even have some 3D Printed parts in our next design…