Dennis Fetters Mini 500

On Tue, 15 Jun 2004 18:46:36 GMT, Dennis Fetters
wrote:



Phillips: 6. Many of the rotating parts lack castelated-pinned locknuts.
If you examine a tailrotor system on a Mini 500 or the Voyager 500, you
will find Nylock nuts again. This is just not normal accepted procedure.
All rotating parts should have hardware that is pinned or has metal locking
nuts with PAL nuts over them.

Armstrong: No comment.

Fetters: There are no rotating parts in the Mini 500 that use Nylock
nuts or all-metal, self-locking nuts. All control joints use an inner
sleeve, and the bolt and nut are tightened to full torque to
retain the sleeve. All working and pivoting is done on the sleeve, never
on the bolt. Therefore
our design is correct. It is only necessary to use a castelated and
pinned nut on a bolt that is used as a pivot, or in a place where
constant disassembly is required.


The link arm to the tailwheel on my tailwind has a ball joint at each
end. The ball joints are fixed to the rudder bracket and tailwheel
bracket with AN3 bolts.
since these are swivelling joints and get a fair hammering on rough
ground I used castelated nuts and split pins to retain them. I must
have had to replace bolts and nuts about every six months because the
nuts would strip.
I discussed the problem with an aircraft mechanic friend of mine who
advised using nylock nuts. I replaced the bolts and nuts and over the
last 3 years of flying havent had to replace a single nut or bolt.
If you look at the nylocks and compare them to castelated nuts you
will find that they have almost twice the thread length.

my experience supports Denis's contention here. Sorry Bill.
Stealth Pilot
Australia.