  We present narrow-band optical images, VLA-A 3.6 cm continuum and H92alpha
emission line data and high resolution long-slit [N II] spectra of Hu 2-1. The
formation of Hu 2-1 appears dominated by anisotropic mass ejection during the
late AGB stage of its progenitor and by variable, ``precessing'' collimated
bipolar outflows during the proto-PN and/or early PN phases. The data strongly
support the existence of a binary central star at center of Hu 2-1: (1) the
brightness distribution of the bipolar lobes and inner shell is
point-symmetric, and the bipolar lobes show departures from axial symmetry; (2)
the position of the central star is off-center; (3) mass ejection towards the
equatorial plane is detected; (4) ``precessing'' collimated outflows are
present. Besides all this circumstantial evidences, the analysis of the
kinematics shows that the systemic velocity of the bipolar outflows does not
coincide with the systemic velocity of the nebula. We propose that this
velocity difference is a direct evidence of orbital motion of the ejection
source in a binary system. Assuming a reasonable range of masses for the
progenitor stars, the orbital velocity of ~10 km/s corresponds to a semi-major
axis of 9-27 AU and to a period of 25-80 yr. The formation of Hu 2-1 is
analyzed within current scenarios of PN formation with binary central stars.
