Re: Blowers, Randall Pepe and others.  The clamp with ends up in the
fins was the drive from shaft to the blades.  The fan floated on the
shaft with basically no play to prevent vibration.

I myself would heat the hub by continually moving around to heat
uniformly and would use only a propane torch.  The purpose for this
kind of drive was to reduce motor noise.

Russ Doering