  This paper discusses the possibility of making an object that precisely meets
global structural requirements using additive manufacturing and feedback
control. An experimental validation is presented by printing a cantilever beam
with a prescribed stiffness requirement. The printing process is formalized as
a model-based finite-horizon discrete control problem, where the control
variables are the widths of the successive layers. Sensing is performed by
making {\em in situ} intermediate stiffness measurements on the partially built
part. The hypothesis that feedback control is effective in enabling the
3D-printed beam to meet precise stiffness requirements is validated
experimentally.
