1. A method for printing a three-dimensional part, the method comprising:
charging an outer surface (19) of a rotating photoreceptor drum (18) with an
electrostatic charge;
neutralizing the electrostatic charge on a portion of the outer surface (19) of the
rotating photoreceptor drum (18) surface to form a layer definition corresponding
to the neutralized portion;
transferring a plurality of charged metal powder particles onto the outer surface
(19) of the rotating photoreceptor drum (18) corresponding to the neutralized
portion; and
transferring the charged metal powder particles from the outer surface (19) of the
rotating photoreceptor drum (18) onto a workpart (70) to form a metal print layer
(66,68).
2. The method as claimed in claim 1, wherein the workpart (70) is a metal workpart positioned on an electrically charged stationary platform (72), and wherein the rotating photoreceptor drum (18) rolls over the workpart (70) to transfer the charged metal powder particles from the outer surface (19) of the rotating photoreceptor drum (18) onto the workpart (70).
3. The method as claimed in claim 1, further comprising:
fusing the metal print layer (66,68) to the workpart (70) using electromagnetic radiation having wavelengths of about 100 MHz to about 300 GHz.
4. The method as claimed in claim 1, further comprising:
prior to transferring the charged metal powder particles from the outer surface (19) of the rotating photoreceptor drum (18) onto the workpart (70), preheating the workpart (70) using thermal radiation.
5. The method as claimed in claim 1, wherein the electrostatic charge is
neutralized by exposing the rotating photoreceptor drum outer surface (19) to a
layer definition using at least one laser beam (54), said layer definition provided
by a controller circuit (56).

6. The method as claimed in claim 5, wherein the charged metal powder particles are delivered from at least one charged powder roller (20) onto the outer surface (19) of the photoreceptor drum (18).
7. The method as claimed in claim 6, further comprising:
after delivering the charged metal powder particles to the outer surface (19) of the photoreceptor drum (18), cleaning any excess powder from the outer surface (19) of the photoreceptor drum (18) using at least one electrically neutral adjustable powder skimmer blade (32,34).
8. The method as claimed in claim 7, further comprising:
depositing said excess powder back into the at least one charged powder roller (20,22).
9. The method as claimed in claim 8, further comprising:
discharging any remaining charge from the photoreceptor drum outer surface (19)
using at least one discharge lamp (42,44); and
re-charging the outer surface (19) of the photoreceptor drum (18).
10. A method for printing a three-dimensional part, the method comprising:
positioning a metal workpart on a stationary platform;
electrically charging the platform;
preheating the metal workpart using thermal radiation;
rolling a rotating charged photoreceptor drum across the preheated metal workpart
to transfer a plurality of charged metal powder particles from an outer surface of
the rotating photoreceptor drum onto an outer surface of the workpart to form a
metal print layer; and
fusing the metal print layer to the workpart using electromagnetic radiation having
wavelengths of about 100 MHz to about 300 GHz.