  After presenting the main difficulties related to machining 5 axes machining
within the context of HSM, we present a surface model of 5-axis trajectories
allowing taking into account geometrical and kinematical constraints. This
model is integrated in an optimization scheme in order to maximize the
productivity while ensuring the expected geometrical quality. A case of
application is detailed, illustrating the modification of the tool axis in
order to improve axis kinematical behavior during the tool path follow-up.
