Well, here's something I hadn't considered before:

3D Printing
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1

Well, here’s something I hadn’t considered before: multiple 3D printers working on all six sides of an object in zero-G
http://aviationweek.com/space/new-tool-space-exploration-onboard-3-d-printer

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Wouldn’t you need at least one face without a print head on it to be able to stabilize the work piece?
Also, I think they’re underestimating current progress on the ground. Some amazing things can be done with it, but just usually requires a knowledgeable troubleshooter nearby.

3

@Cliff_Bramlett Well, if the 3D printers are “fixed” to the object, or to a platform holding the object, stabilization wouldn’t matter in weightless conditions, as long as the entire apparatus doesn’t go spinning off. (just guessing here, we need to try it out.)

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I would expect that without at least one stabilized surface the object in the center would drift as the heads move around. I’ve been in zero G microgravity and things don’t just stay put.

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@Cliff_Bramlett I think we are saying the same thing. The object being worked on has to held in some manner in order to apply material, and to keep the entire thing from floating off, it would also need to be tied down to something. Still, I think it could be possible to have multiple 3D devices working simultaneously on an object. How many might just depend on how many surfaces are available. Why not 12, to build a dodecahedron?