[TowerTalk] Add on 3" mast brake?

[Grant Saviers]

Searched for the BMW driveshaft damper part - $1200 from BMW with a $500 
discount, $31 on ebay.  Could there be a quality difference  ;) ??

Also, could make one from multiple threaded end (plate/plate) vibration 
isolators, but that would cost more.

https://www.mcmaster.com/64885K33 or Kipp from MSC

https://www.kippusa.com/xs_db/DOKUMENT_DB/www/KIPP/BEDIENTEILE/Technische_Hinweise/enUS/TH_009_Gummipuffer_enUS.pdf

Grant KZ1W


On 11/16/2022 06:10, jim.thom jim.thom at telus.net wrote:
> M2, at one time, did offer the BMW rubber coupling isolation assy, for
> their OR-2800  rotors. The rubber coupler was sandwiched between 2 x new
> plates.  The 2 x new plates were bolted  between the oem drive plate...and
> the oem mast clamp assy.
> 
> When I went to buy it, I was told it had been discontinued.  Reason given
> was hams  were....'not doing proper maintenance' on the completed assy. The
> various new bolts were loosening up everywhere.
> 
> Permatex now makes... 'orange'  threadlocker. It's as strong as ..'red'
> but easy to get off like ...'blue'.  IE: No heat required.  That would
> probably have done the trick.
> 
> Shorting the windings on a DC motor is a simple idea, superb. On my small
> (K7NV + RT-21) prop pitch, it has 2 x windings, so both windings would have
> to be shorted, non issue, moot point.
> 
> Yaesu at one time offered an..'anti vibration pad' that was installed
> between the base of their rotor..and the  rotor plate. IMO, it won't do
> much of anything.
> 
> Still another method that was used back in the 60's and 70's was 2 x masts,
> one inside the other, with a good overlap...like 1'.  A coil spring, like
> used on the front end of a car's suspension, was slid over the overlapping
> mast tubes.  Top of the spring was welded to the upper mast...and the lower
> end of the same spring was welded to the lower mast.  There is just enough
> compliance between the 2 x mast sections, that the spring absorbs the
> vibrations.  It worked on the same idea as the BMW rubber coupling.
> 
> The drawback of course is the 2 x tubes are not bolted together, and the
> top mast tube must be able to freely rotate inside the lower mast tube. The
> overlapped portion was lubricated.  Welding required.    The assy was
> installed between the rotor plate and the top plate. The main mast tube,
> (the long, main  3rd tube), was slid through the top plate..and coupled to
> the   2nd tube.  It worked, but I only knew of a few instances where it was
> used.   The BMW rubber coupling version would be easier to implement,
> install, and / or replace if required.
> 
> Jim  VE7RF
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