The gun was made using 33 17-4 Stainless Steel and Inconel 625 components, along with a selective laser sintered (SLS) carbon-fibre filled nylon hand grip.
The gun was created with a metal laser sintering process and then stress relieved. “The 17-4 Stainless Steel has not been post heat treated, which would further strengthen it. We wanted to test the material in a raw form first,” says Eric Mutchler, project engineer at Solid Concepts. “We still have heat treatment options and further Inconel Super Alloys in 625 and 718 to try should our 1911 show any indication of failure.” The process used 40 micron layers and the metal barrel was grown with rifled lands and grooves as per its CAD design, as were the other components (except for the springs, which were not printed).
The successful production and functionality of the 3D printed metal gun proves the viability of 3D printing for commercial applications, the company said. Solid Concepts built the gun from a public domain 1911 design.
The metal laser sintering process uses was accurate enough to build the interchangeable and interfacing parts within the gun and the 3D printed metal had fewer porosity issues than an investment cast part and better complexities than a machined part. The gun barrel has chamber pressures above 20,000 psi every time it is fired.
“We’re proving this is possible, the technology is at a place now where we can manufacture a gun with 3D metal printing,” says Kent Firestone, vice president of additive manufacturing at Solid Concepts.
“The whole concept of using a laser sintering process to 3D print a metal gun revolves around proving the reliability, accuracy and usability of metal 3D printing as functional prototypes and end use products,” says Firestone. “It’s a common misconception that 3D printing isn’t accurate or strong enough, and we’re working to change people’s perspective.”
The benefits of 3D printed metal components also include the possibility of quickly replacing components by simply re-printing them with design corrections.
To date, the 1911 3D printed gun has been subjected to 600+ rounds without any part failures.
