98a-Thorax: 2 Wings, each 1 DOF

Completed Sept 1998. Status: Disassembled

(a) Close-up view of 98a

(b) Actuation by VCAs


Thorax 98a consists of a brass cylindrical body with springs (302 stainless steel, 2.5mm long,
0.229mm wire diameter, 1.14mm spring diameter, 11 turns) mounted on the sides. On the springs
were mounted brass wings (7mm long, 5mm maximum chord; later steel wings, 10mm in length,
100 microns thick, were also available using the EDM process). The wings were driven using voice
coil actuators (VCA) coupled to the springs through connector rods.

Wing length, l 7mm
Wing mass moment of inertia, I 1.14e-8 kg x m2
Damping, x 0.0228
Resonant Frequency with wing, w (f)311 rad/s (49.5 Hz)
Quality Factor, Q 22