In this edition of 3D Printing News Briefs, we’re starting with research and moving on to software, and then ending with a fun story about a cool DIY print. LLNL conducted a study about the droplet ejection process in a new metal 3D printing method. FreeCAD has directly integrated the 3DfindIT.com visual search engine by CADENAS. Finally, a maker used 3D printing to build a bartop arcade cabinet that’s entirely powered by Raspberry Pi.

LLNL Simulates Droplet Dynamics in Metal 3D Printing

A comparison between the experimentally observed ejected droplet shape at break-up (a) and the simulated droplet shape (b) at various operating conditions approaching the experimental conditions. The simulated droplet shape significantly differs from experiments, highlighting the fact that essential physics appear to be missing from the model. Image courtesy of Andy Pascall/LLNL.

A team of scientists from Lawrence Livermore National Laboratory (LLNL) published a research paper about the dynamics of droplet ejection that could help advance 3D printing. The researchers simulated the ejection process and breakup dynamics of droplets in a novel AM process called Liquid Metal Jetting,  or LMJ, which jets molten droplets of liquid metal from a nozzle to 3D print parts without the use of powder or lasers. First, they built a custom liquid metal 3D printer that could dispense tin droplets, and used it as a testbed for droplet-on-demand, freeform metal printing, with high-speed video helping to track the dynamics of the droplets during ejection. Then, thanks to the video analysis, the team built a computational model that can simulate the ejection morphology of the tin droplets, and demonstrated that LMJ, while repeatable and very stable, is very tough to model.

“We don’t currently have a good understanding of all of the physics that occur right when the droplet breaks off from the metal jet. This model points to additional physical mechanisms that might need to be considered to close the gap between experiments and modeling,” explained co-author Andy Pascall.

Future research by the team will involve exploring droplet ejection across more process parameters.

3DfindIT.com Integrated Into Open Source FreeCAD

The CADENAS visual search engine 3DfindIT.com has been directly integrated into the parametric, open source FreeCAD software, version 0.19 in a new add-on. This will give designers and engineers access to millions of 2D and 3D CAD models from more than 2,500 manufacturer catalogs, and accelerate high-quality product design through digital component information from the intuitive search engine, which will allow them to add the engineering data they want right into their designs. CADENAS writes that it should only take a few clicks to find CAD components in the CAD software, configure them accordingly, and then transfer the engineering data into their designs for free.

FreeCAD version 0.19 users can access this through the AddOn Manager, or through GitHub. Once this add-on has been installed, simply select the “3DfindIT” menu item in FreeCAD to access the component manufacturer-verified data. Depending on which catalog you’re looking at, the digital components feature plenty of helpful metadata, like part numbers, materials, and environmental standards. By adapting search methods, like Function Search and 3D Shape Search, to the specific needs of CAD users, 3DfindIT.com is said to be able to really help speed up a product’s time to market.

3D Printed, Raspberry Pi-Powered, Bartop Arcade

Image courtesy of Print ‘N Play YouTube channel

3D printing and retro gaming lover James, who runs the Print ‘N Play YouTube channel, designed the full-size bartop arcade cabinet above, which was entirely fabricated through the use of 3D printing. He used Autodesk Fusion 360 software to create this amazing DIY cabinet case from scratch, designing it as a single unit before breaking it up into 3D printable pieces. Pegs are used to fit each piece into place, and the giant cabinet, which is powered by a Raspberry Pi 4 running RetroPie, features ventilation holes, a mounting panel for the Raspberry Pi, and space for input peripherals. It also has two top-mounted speakers, LED-backlit arcade buttons, and its widescreen display and double joystick setup is meant for two players.

“Arcade games are fun! And many are best enjoyed with friends,” the video description states. “Today we 3D Print a FULL-SIZED Bartop arcade cabinet that lets two players play simultaneously! That’s a LOT of plastic!”

Check out the Print ‘N Play channel on YouTube to see the final result. You can also find designs by James on Thingiverse under user name JCriotz.