Single Bolt Stud
By Simon Van Leeuwen
07-02-98

As was mentioned on the GSAL forum, those who have Quadra 75XL's (or
similar engines)might like to utilize one of these studs.
These engines are supplied with a bolt to secure the propeller to the
aluminum hub.
Due to varying thicknesses of prop hubs which may cause the
bolt to bottom before the prop is tight, and the inherent wear/galling of
running metallic bolts into aluminum threads (especially without the right
thread lubricating compound), I bought a length of hardened (GR5) rod.
I cut a piece of the rod to 3.5", drill and bottom-tap to 0.5"(on a lathe)
one end for the 10-32 spinner bolt. I then Loctite this threaded rod into
the aluminum hub (semi-permanent).
Any propeller can now be secured using a hardened 3/8"-24 nut and the
spinner bolt attachment point is now fixed! You have done away with hub
thread wear, tapping the bolt for your spinner and possibly carrying
different prop/spinner bolts.
One fellow actually had a failure when he thought his prop was tight when
actually the bolt had bottomed out against the front of the crank!
The point is, I had to buy 36". For those who would be interested in
getting one for your engine(s), I'll machine one for $15.00 (which includes
shipping, a steel washer to put against the big aluminum washer and a
hardened nut). There are eight available.