For the 2nd time this week, we’re seeing a home version of the very large powder based printers. If you’re unfamiliar, a powder based printer has a very distinct advantage that it doesn’t need to worry about parts being supported. With a typical filament based printer you have to keep in mind that there has to be a surface to print on, so many workarounds have been created. Even with the workarounds, printing fully moveable and interlocking parts can still be less than desireable. Powder printers, while messier and considerably more expensive, have no problems whatsoever with this issue. The powder material acts as its own support structure allowing for you to print whatever shape you want without issue.
Plan B uses an inkjet head as a delivery system to bind particles of powder together. You can see it passing over the powder bed and depositing a layer of the model before more powder is added on top. This method opens up the possibility of multiple colors, but also unfortunately produces some very fragile parts. The solution proposed in this situation is to coat your parts in super glue after they are printed.
This printer is currently open source and the plans can be found on this website. This includes a detailed breakdown of all the parts involved, how to modify inkjet cartridges and how to assemble the entire system. There are also plans for a “depowdering station” which is fairly important as your parts, when finished, are embedded in a solid cake of very fine powder which has to be removed.