in order to fabricate a core half. The core disk [see Fig. 8(b)] was
bonded to a printed-circuit board using cyanoacrylate to stabilize
the core during the routing process. The winding groove in each
core half was routed by a T-Tech QC-5000 prototyping machine
using a 15-mil square end-mill bit. The empirical settings of
the prototyping machine for 1-mm-thick core disk are a spindle
speed of 15 000 rounds/min and a routing velocity of 2 in/min.
After routing, the core was released by soaking in acetone for
half an hour.