<VV> Late Fan Blades

[CorvairEd at aol.com]

In a message dated 4/11/05 7:49:31 A.M. Pacific Daylight Time,  
pat_wieber at yahoo.com writes:

Question: Why are the late fan blades unequally spaced?
My guess  would be harmonics, to stop the mag from
ringing at particular speeds. The  earlier steel fans
seem symmetrical. 


Pat,
You guessed right, to stop harmonic ringing.  If you look
closely you will find that the early fan blades are also 
unequally spaced for the same reason.  Water pumper
fan blades are unequally spaced too, same reason.  Also
applies to the generator and alternator fans.
 
Ed Corson  (CORSA Member)
IECC