Wheel Crankpin Hole 1
17-Jan-2006
We designed, and built a fixture to hold the wheel
to make the crankpin bores. The pin was threaded and mounted to a
plate, and the plate was clamped to the mill table. The pin is a _very_
close, slip fit to the axel bore.
The wheel is mounted on the pin resting on two
parallels and clamped down. Before the final tightining, the center on
the lobe is centered on the mill spindle axis. The first wheel I used
the scope, but I re-did it, and all the other wheels, using a center
drill mark on a scribed center line.
After the center hole was center drilled, the first
through hole was drilled 1/4". Then a 1/2" hole was drilled, followed
by a 19/32". The boring head was then used to make the hole round and
straight, and the hole brought to 0.605 diameter. Finally, a 0.625
reamer was used to bring the hole to diameter.