LMP

2 Articles

Metal 3D Printing Gets Really Fast (and Really Ugly)

February 17, 2024 by 8 Comments

The secret to cranking out a furniture-sized metal frame in minutes is Liquid Metal Printing (LMP), demonstrated by researchers at the Massachusetts Institute of Technology. They’ve demonstrated printing aluminum frames for tables and chairs, which are perfectly solid and able to withstand post-processing like drilling and milling.

The system heats aluminum in a graphite crucible, and the molten metal is gravity-fed through a ceramic nozzle and deposited into a bed of tiny 100-micron glass beads. The beads act as both print bed and support structure, allowing the metal to cool quickly without really affecting the surface. Molten aluminum is a harsh material to work with, so both the ceramic nozzle material and the glass beads to fill the print bed were selected after a lot of testing.

This printing method is fast and scalable, but sacrifices resolution. Ideally, the team would love to make a system capable of melting down recycled aluminum to print parts with. That would really be something new and interesting when it comes to manufacturing.

The look of the printed metal honestly reminds us a little of CandyFab from [Windell Oskay] and [Lenore Edman] at Evil Mad Scientist, which was a 3D printer before hobbyist 3D printers or kits were really a thing. CandyFab worked differently — it used hot air to melt sugar together one layer at a time — but the end result has a similar sort of look to it. Might not be pretty, but hey, looks aren’t everything.

(Update: see it in action in this video, which is also embedded just below. Thanks [CityZen] for sharing in the comments!)

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Silicone Molds For Stove-Top Metal Casting

August 9, 2017 by 25 Comments

Casting metal parts from 3D-printed plastic or Styrofoam models is all the rage these days, and for good reason — casting is a way to turn one-offs into mass-produced parts. Seems like most of the metal casting projects we feature are aluminum in sand molds, though, so it’s refreshing to see a casting project using silicone molds to cast low-melting point metals.

Don’t get us wrong — sand-cast aluminum is a great method that can even be used to build a lathe from scratch. But not everyone wants to build a foundry and learn the sometimes fussy craft of creating sand molds. [Chris Deprisco] wanted to explore low-melting point bismuth alloys and set about making silicone rubber molds of a 3D-printed Maltese falcon. The bismuth-tin alloy, sold as a substitute for casting lead fishing weights, melts on at 281°F (138°C) and is cool enough for the mold to handle. Initial problems with bubbles in the cast led to a pressure vessel fix, and a dull, grainy surface was fixed by warming the mold before the pour. And unlike sand molds, silicone molds are reusable.

Of course if aluminum is still your material of choice, there’s no need for a complicated foundry. A tuna can, a loaf of bread, and a handful of play sand is all you need to make custom parts.

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