Date: Tue, 8 Nov 2011 00:46:02 -0000
From: <john@kk9a.com>
Subject: Re: [TowerTalk] Pinning mast?
You didn't say what kind of mast clamp you are using. While pinning a mast
is good thing in many cases, I think you need to correct the fit of the mast
clamp before going any further. My prop pitch has a 3" K7NV mast clamp and
my mast is 2 7/8 diameter so I purchased as 3" diameter stainless steel tube
with a 1/16 wall and made a shim out of it. The clamp then tightened to the
mast securely. Why won't yours shim properly?
John KK9A
## kurt has detailed instructions on how to pin a mast correctly.
http://k7nv.com/notebook/id9.htm "pinning masts"
http://www.k7nv.com/proppitch/ Scroll down to see the
infamous K7NV mast clamps for PP rotors. I have the
small PP with the 2" mast clamp + mating GH control box.
http://www.k7nv.com/proppitch/id35.htm this is his 2"/3" mast
clamps...but for an OR-2800 rotor.
I'm sure he can make his mast clamps in any size you want...like to
handle a 2.875" mast for example. What type of mast clamp do you have
on the PP right now ?? If you are using a 3" mast clamp and the mast is
2.875"
you can shim it with just about anything, like a short piece
of 3" irrigation tubing [.050" wall]. just slit it down one side..[or a 2nd
slit
180 deg opposite]
You can also wrap the lower end of the mast with that heavy duty non skid
stuff, used for
stairs. It come's in 1"-2"-3" width's..and on long rolls, and sells by the
foot.
Sticky back on one side and like sandpaper on the other side. It won't budge.
You can also use it on inside of the mast clamp. Ok, now you have two
sandpaper
surfaces butted up, touching each other. It won't budge. Waterproof too.
You can also use it on one / both sides of any shim.
I used that same non skid stuff on my HB mast steps which are made of 2" x 2"
x 1/4"
thick 6061-T6 angle Al. [14" long each]. I applied it to both the
horizontal and vertical
portions, so my hands + feet won't slip.
Kurt's PP mast clamp and his OR-2800 mast clamps are the.....'real deal'.
You barely
tighten them, and it pinch's the mast so tight, it's not gonna slip, ultimate
mast clamp..
albeit expensive, but I don't have time for bs mast clamps these days. Do it
wrong
and you just have to end up doing it right the 2nd time anyway. Cheaper to do
it
right the 1st tine around. He use's transverse gr -8 bolts on his mast
clamps. The mast
justs slides into his mast clamps, snug fit. With No bolts and just some vice
grips pinching
his clamp, it still won't budge ! His clamps work simply cuz they have a
massive, huge surface
area. The tips of the teeth on an OR-2800 mast clamp don't compare,
miniscule surface area.
later... Jim VE7RF
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