[TowerTalk] TowerTalk] Pinning mast?

[K8RI]

On 11/8/2011 2:22 AM, Jim Thomson wrote:
> Date: Tue, 8 Nov 2011 00:46:02 -0000
> From:<john at 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?

What about building, or purchasing a mast clamp that mounts on a flat 
plate and is adjustable for centering, much like the mast clamps used in 
the PST- series...of ProSistel rotators?

73

Roger (K8RI)

>
> 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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