Researchers at Boeing have published a patent describing a bizarre method of 3D printing that involves levitation. I am skeptical.
The curious patent, US Patent Application No: 2016/0031,156, is entitled, “Free-Form Spatial 3-D Printing Using Part Levitation”, and states this abstract:
A part is fabricated by an additive manufacturing process while levitating in space. Constituent features of the part are formed by 3-D printing. A part levitation system allows the spatial orientation of the part to be manipulated relative to one or more print heads.
This is perhaps a little hard to visualize, let alone believe, but here’s how it is supposed to work:
A “nugget”, or base piece is levitated in free space, either by magnetic or acoustic levitation.
The print “space”, in which the nugget is suspended, is surrounded by at least one, or a number of 3D print extruder-like devices, which “print” onto the object.
The levitation system (somehow) enables the nugget and attached print material to be rotated in all directions, exposing the surface to all the extruders.
The nugget spins, the extruders extrude, and material accumulates on the surface of the nugget to gradually form the final object.
Could this actually work? Let’s think about a few things.
First, the levitation component, which is key to making this work. It is possible to levitate small objects if they are placed near a supercooled magnet, according to the Meissner effect. By combining several such supercooled magnets together and moving them in appropriate directions, it’s possible you might be able to perform arbitrary rotations on a levitating object.
But there are limitations: the size of an object must be small to be sufficiently close to the magnets, limiting the volume of a printed object that must wrap the outside of the levitated nugget.
Acoustic levitation is also possible, but I’m wondering if the acoustic waves would ALSO interfere with material deposition? Unless the deposition takes place very close to the print surface, the acoustic waves might make a mess of things, if a spray-style deposition technique were used.
The supercooled requirement for the magnetic approach also may affect material deposition. As readers know very well, the temperatures involved in 3D printing materials often have to be very precise to obtain desired results. By planting a supercooled object in the middle of print operations, there will certainly be extreme temperature challenges to engineer around.
Print speed could be a concern. While it’s possible to obtain speedups by adding more extrusion devices in all 360 degrees around the print volume, it’s not clear how small such devices will be, and how close to the target they must remain. If close, then fewer devices can fit, limiting potential parallel printing speedups.
I suspect this approach might actually work, but with at least initially, severe limitations in print volume, print speeds and choice of materials. It may also prove quite expensive.
While this particular patent seems extremely unusual, it does underline the fact that we are definitely not done innovating 3D printing processes. There are likely to be many more such announcements in the future.
Via Google Patents