Rosotics, an Arizona startup, claims its “rapid induction printing” method can print massive metal objects at high speed, low cost, safety, and energy economy.
A large printer distributes molten metal in layers onto a substrate, which then solidifies. Printing from the ground up allows you to construct shapes that subtractive manufacturing can’t, making it ideal for quick prototyping and small-run items.

Cheap, fast induction tech enables unlimited-size

Lasers melt powdered metal feedstocks in several metal-printing technologies. Rosotics founder and CEO Christian LaRosa claims laser systems have several issues. Secondly, powdered metal feedstocks are costly and dangerous—powdered titanium is explosive. Lasers are poor heat converters. Massive laser-based systems may need energy supply systems.

Finally, a reflected beam of sufficient power can blind someone if it hits them in the eye. Fourthly, these methods require heat-treatment, thus you can only print pieces as big as your oven can bake them.

LaRosa thinks he’s found a way to solve all these problems and print enormous metal components for airplanes and rockets cheaply, easily, and quickly. The Mantis, a revolutionary metal 3D printing head from Rosotics, uses induction to heat metal effectively.

On a video chat, LaRosa says, “It’s a really natural manner of 3D printing metal.” “You produce an electromagnetic field from a coil, and any ferromagnetic metal that passes through that field gets heated inductively by the eddy currents you’re producing. Wire is fed via a nozzle and inductively heated without the laser. Rapid Induction Printing (RIP). It does the same with less energy.”

Induction technology is rapid, low-cost, and enables 3D printing in metal at any scale.

How efficient is it? LaRosa argues laser-based processes are inefficient. “It’s optical heat transfer. Induction increases efficiency significantly. The laser-based wire-feed technique is 30–50% more energy-efficient than directed energy deposition. It may be an order of magnitude more than others.”

Ferromagnetic feedstock isn’t necessary. “Aluminum was a significant target for us, because it provides the basis for a lot of structural elements in aircraft, and it’s not magnetic,” adds LaRosa. We used breakthrough metallurgical technology to inductively heat that feedstock. The target feedstock can go through an inductively heated conduit or a jacket of inductive material.

This expands the technique to several metals. LaRosa asserts it can handle most metals after rigorous testing with steel and aluminum: He claims it can handle aeronautical materials and niches well. We can adapt the procedure to handle materials that push the limitations. Titanium is workable, but we’re investigating alternatives. Cupronickel, which performs well mechanically, is one of the most immediate. Nonetheless, the method works effectively with any commercial wire material.”

LaRosa believes the printer can scale up by extending the nozzles. It presently handles wires between 1 and 10 mm.

Rosotics designed a stylish prototype. “There’s a full-scale printer prototype behind the wall on my side here that prints to approximately 26 feet (8 m) in width, and about 20 feet (6.1 m) in height,” explains LaRosa. Three heads on that machine press about 15 kg (33 lb) of metal every hour. It drops 50 kilogram (110 lb) each hour. It’s powered by a 240-volt outlet like you’d find in a warehouse. If you were running a large-scale wire-based laser printer, you’d definitely contact the power provider for a larger grid connection. It says a lot—efficiency simplifies everything.

“Our approach works in open air, too,” he adds. To eliminate residual stresses from other laser-based procedures, heat the structure evenly. Post-print operations are unnecessary. It streamlines the process. “There may be a handful of large-scale heat treatment furnaces in the US.”

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