Most 3D extrusion printers force a line of molten thermoplastic onto the object under pressure, where it cools into a solid, not dries. I suspect any modifications for zero g were on other components of the printer.

Granted, for the “laying of layers,” the surface tension for a liquid would be fine and dandy. Now, the drying becomes the crucial step, particularly when constructing a tool or part that would undergo stress when in use, regardless of critical need. In a micro-G environ, would the printed object be packed dense enough for the task at hand, or would the molecular structure be too sparse for use (crumbly)? I still think the printer would need to be placed on a spinner, or just the drying platform, if only for the duration of drying.

“Houston, we’d all like to step outside for a few minutes.”

Have you seen the youtube video of Chris Hadfield showing how water clings to a washcloth?

http://www.youtube.com/watch?v=Ff7oUycGJRY

The natural bonding effect of surface tension could be further augmented, however, with a slowly rotating print chamber, at around 0.5-G or better.

A 2 meter diameter (a bit more than 6 feet) centrifuge spinning at 30 rpm, or 1 every 2 seconds, would grant a G-force just over a value of 1 gravity.

Interesting experiments will likely follow its installation.

I haven’t yet had the opportunity to play with a 3d printer, though its on my Christmas list, right next to quadrocopter.

It always bugs me a little when they call low earth orbit zero-gravity. If it was zero-gravity, they wouldn’t be orbiting…