Archive for the ‘Metal’ Category

Laser Engineered Net Shaping (LENS) / Direct Metal Deposition (DMD)


LENS and DMD are the same technology. LENS/DMD is used to print parts out of metal using a print head (as opposed to the DMLS process). The print head moves in all three axes. A laser is focused through the print head and metal powder is injected into it. The powder is sintered as it exits the head and is put down on the model.

An inert shroud gas is used inside of the print head to shield the metal from oxygen (so that it sinters correctly and can be controlled more accurately).


These technologies have been utilized to fabricate and repair injection molding machines, and to create specialized parts for aerospace applications.

LENS/DMD is limited at the moment because support structures would have to be made out of the same material as the model, which makes them difficult to remove afterwards.

• The printed objects usually have desirable metallurgical properties and are completely dense.
• Can be used not only to fabricate but to repair parts (something DMLS is not capable of doing).

• Severe overhangs are an issue because of a lack of a different material for support structures.
• Objects usually require some post-print machining.

Direct Metal Laser Sintering (DMLS)


DMLS is identical to SLS, except that the machine sinters metal powder instead of plastic powder. The model does not require a finishing stage.

According to, DMLS is capable of printing steel alloys, stainless steel, tool steel, aluminum, bronze, cobalt-chrome, titanium, and ceramics.

One of the most common uses for DMLS is “rapid tooling,” which is the production of specialized tools that go in machines; these tools may be specific to one application in one machine and therefore aren’t produced in mass quantities. The cost of traditionally producing one of these pieces (by CNCing, casting, etc.) is extremely expensive and wasteful in comparison to printing it. DMLS has proven successful for making these sorts of parts. has an excellent article on a 2003 collaboration between two companies (Morris Technologies and Extreme Tool & Engineering) testing the pros and cons of using DMLS to make molds. They were somewhat disappointed with the results.

• No waste is generated and little energy is used, as compared to traditionally machining an object. This is great for prototypes and one-offs.

• In Morris and ET&E’s test, the mold they printed had a considerable amount of warpage and required additional machining, as well as polishing. Bottom line: not a good solution for moldmaking.