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Solid Concepts Manufactures First 3D-Printed Metal Pistol
Zothecula writes "In a prime example of past meets future, a Texas-based company has used a century-old classic firearm as the blueprint for the world's first 3D-printed metal gun. Solid Concepts' use of a laser sintering method to create a fully functional Model 1911 automatic pistol is the latest demonstration of the potential of 3D printing techniques in industrial processing. The company's 'The gun proves laser sintering can meet tight tolerances. 3D Metal Printing has less porosity issues than an investment cast part and better complexities than a machined part. The barrel sees chamber pressure above 20,000 psi every time the gun is fired.'"
better complexities than a machined part.
But weaker parts.
When making metal parts the the metallurgical properties are more important than the shape. The direction of the molecules in the metal make the difference between something that's hard and brittle vs. something that's soft and elastic.
I work with a lot of different rapid prototyping processes - including DLMS - on a weekly basis. In their current form you cannot change materials mid-part on a DLMS machine. Even if the machine itself could handle it (i.e., had multiple material-handling streams), you would have a tough time getting the dissimilar metals to properly fuse. As a welder how good the results of welding aluminum and steel are, or titanium and steel. Mixing these metals tends to result in brittle intermetallic phases, which are perfect places for fracture. Even worse is that, because the machine works layer-by-layer, the boundary between the two metals would be planar, making fracture all that more likely.
What is more, because the process is akin to SLS, what you end up with is a box - the build envelope - completely filled with powder, inside of which is the part you've made. You can ordinarily reclaim most of the powder and use it again. If you were to change materials mid-stream, you would have to junk most if not all of the leftover powder, because you wouldn't have a good way to separate the powders.
Well, not exactly. It protects against many more threats than just criminals with firearms. It protects against anyone that seeks to do substantial physical harm to you or your family regardless of their means (aka baseball bats, lead pipe, brass knuckles, etc.)
As for the last assumption, you are most likely referring to the Kellermann report which stated that a firearm in the home is 43 times more likely to kill a family member, friend or acquaintance. That report has been debunked many times as it specifically excluded most accounts of self defense and included suicides and even police actions against criminals in the statistics. And of course these are all statistics 30 years out of date, where the murder rate of US citizens has steadily declined to less than half of what it was in 1986. (despite what the media portrays)