Development of a multi-piece multi-gate mold for manufacturing a flapping wing drive-mechanism

Successful realization a flapping wing microair vehicle (MAV) requires development of a light
weight drive-mechanism that can convert the
continuous rotary motion to oscillatory flapping
motion. Molded compliant drive-mechanisms are
an attractive design option because of
manufacturing scalability and reduction in the
number of parts. The unique characteristics of
this mechanism require development of a
complex multi-piece multi-gate mold design.
This paper describes a systematic approach for
determining the part shape and size, optimizing
the mold pieces, and placing the gates on the
multi-piece mold. The novel aspects of this work
include (1) selecting non-critical shape features
to optimize the mold design and (2) the use of
sacrificial structural elements to reduce the
impact of the weld lines on the structural
performance. The mold developed using our
approach was utilized to realize a working
flapping wing MAV.