This shaft holds an orientor head that plunges into the parts and then spins to align them correctly for a subsequent forging operation. To make this shaft in very low volumes, I had to push the limit on an EDM operation. I used a blind, backward-tapered bore that could only be made in this hardened shaft with a Sinker EDM, both for the form and the required tolerances. The shaft cost $800 to produce and is still used in production today, running 3 million parts per year.
Application:
Changing from running one product version to another happens about once per day and can take an hour out of production. Every second counts and with the old orientor shaft, the operator had to bolt the orientor head to the shaft. Without making any change to the inventory of orientor heads on hand, I changed the shaft design to take this change-over operation from roughly 4 minutes down to less than 10 seconds, and that without any tools required.