  An additive manufacturing (AM) process often produces a {\it near-net} shape
that closely conforms to the intended design to be manufactured. It sometimes
contains additional support structure (also called scaffolding), which has to
be removed in post-processing. We describe an approach to automatically
generate process plans for support removal using a multi-axis machining
instrument. The goal is to fracture the contact regions between each support
component and the part, and to do it in the most cost-effective order while
avoiding collisions with evolving near-net shape, including the remaining
support components. A recursive algorithm identifies a maximal collection of
support components whose connection regions to the part are accessible as well
as the orientations at which they can be removed at a given round. For every
such region, the accessible orientations appear as a 'fiber' in the
collision-free space of the evolving near-net shape and the tool assembly. To
order the removal of accessible supports, the algorithm constructs a search
graph whose edges are weighted by the Riemannian distance between the fibers.
The least expensive process plan is obtained by solving a traveling salesman
problem (TSP) over the search graph. The sequence of configurations obtained by
solving TSP is used as the input to a motion planner that finds collision free
paths to visit all accessible features. The resulting part without the support
structure can then be finished using traditional machining to produce the
intended design. The effectiveness of the method is demonstrated through
benchmark examples in 3D.
