The plastic injection mold manufacturing process includes polishing
operations when surface roughness is critical or mirror effect is required to
produce transparent parts. This polishing operation is mainly carried out
manually by skilled workers of subcontractor companies. In this paper, we
propose an automatic polishing technique on a 5-axis milling center in order to
use the same means of production from machining to polishing and reduce the
costs. We develop special algorithms to compute 5-axis cutter locations on
free-form cavities in order to imitate the skills of the workers. These are
based on both filling curves and trochoidal curves. The polishing force is
ensured by the compliance of the passive tool itself and set-up by calibration
between displacement and force based on a force sensor. The compliance of the
tool helps to avoid kinematical error effects on the part during 5-axis tool
movements. The effectiveness of the method in terms of the surface roughness
quality and the simplicity of implementation is shown through experiments on a
5-axis machining center with a rotary and tilt table