Designing a printer that can create
three dimensional objects is no small
feat, but being able to achieve the
same goal with a fraction of familiar
gravity is much more challenging.
Gravity is necessary for proper
extrusion on normal printers, so the
extruder in the lower g environment
must apply a greater force to extrude
material and posses
more effective control when laying
down material.
The
Bernoulli Equation is a nearly
universal equation in fluid dynamics
which essentially states that with
an increase in the speed of a given
fluid, the pressure decreases.
Bernoulli’s Equation can help
describe the 3D printer hot end
extrusion process.
The pressure required
to extrude the filament will be
determined from the mechanical energy
given by the torque times the
rotational speed of the gear. The
extruder would also have to cool the
filament right after it is placed to
avoid the molten, liquid filament
drifting away. Successful tests have
already been completed of micro and
zero g printers by the US company Made
in Space, and finished prototypes are
aboard the International Space Station
(ISS). On the Moon, the gravity is
much lower than Earth’s, but still
present, which will not require as
much energy to extrude and control
material.
