A few weeks ago the guy who keeps things running at work asked if I could help out with some fan blades on a coolant pump. The original blades were held on by a setscrew thru the side of the plastic hub. It kept coming lose and had chewed up the shaft.
I do not like setscrews even when they are not threaded thru a plastic hub so I designed some blades with a tapered bushing that would bridge the chewed part of the shaft and clamp on the better parts.
Replacement and the tapered bushing
A little bit under extruded but it is working just fine.