[Towertalk] Prop-Pitch

[Gerald D'Entremont]

While we're on the subject...if anyone has a 'spare' bevel gear
from a junker or knows someone who does, I'd appreciate a
referral.  I also have need for one of the outer cylindrical motor
housing 'cans'.  Both of these are for a 'small' Curtiss/Wright.
Tnx/73, Gerald  W5BA  w5ba@compuserve.com

----- Original Message ----- 
From: GALE STEWARD <k3nd@yahoo.com>
To: towertalk reflector <towertalk@contesting.com>
Sent: Monday, June 03, 2002 7:06 AM
Subject: Re: [Towertalk] Prop-Pitch


> 
> My PP is mounted to a modified Rohn rotator mounting
> plate.  I took it to a machine shop and had them cut a
> larger center hole in it.  Think it 5 or 6 inch
> diameter.  You DO need the bevel gear to make any type
> of coupling to the mast.  I used an output shaft and
> clamp assembly from a trashed Hygain RotoBrake 400.  
> I need to get up my tower with the digital camera then
> I could post some pix.
> 
> 73, Stew  K3ND
> 
> 
> --- dan hearn <dhearn@ix.netcom.com> wrote:
> > Hi Greg: You are correct, they are mounted to a
> > plate with a  hole in it
> > large enough to let the output shaft pass thru it.
> > The unit shown in the
> > ebay add is missing a large bevel gear which mounts
> > to the splined
> > output shaft. Most people weld a bushing to the
> > bevel gear for attaching
> > the tubular mast and the bevel gear takes the
> > vertical load. It is
> > possible to use the splined shaft for output by
> > machining a mating
> > bushing.
> >   You do need a direction indicator. If the bevel
> > gear is on the unit,
> > some people make a large gear out of sheet metal the
> > same diameter which
> > will mesh with it to rotate a potentiometer or
> > selsyn. Some of the PP
> > mod articles have dimensions so you can make it with
> > a drill and a file.
> > I have used sprocket and chain drive as well as a
> > small dial cable and
> > pulley arrangement to turn a potentiometer. 
> >   It is essential that the top of the unit and the
> > indicator you use be
> > protected from weather. I have seen PP motors in
> > flea markets which were
> > not protected and the bevel gear and the ball
> > bearings beneath it are
> > rusted. 
> >   M2 sells a modified version of their OR 2800
> > control and indicator box
> > for PP motors. You attach a small magnetic pickup to
> > the motor shaft
> > which generates pulses as you rotate and the unit
> > supplies power for the
> > motor.. The price is around $500 I believe.
> > 
> > 73, Dan, N5AR 
> > 
> > Greg Gobleman wrote:
> > > 
> > > I was looking at the photos of this prop pitch,
> > not having seen one mounted
> > > I was trying to figure out how they are installed.
> >  I assume the flat plate
> > > area is bolted to a stationary plate.  Is a
> > notched piece made to adapt to
> > > the mast pipe?  I also have read of needing to rig
> > a directional indicator
> > > of some kind.  Any info on that?  May I assume
> > that the control box and
> > > indicator will probably cost as much as the rotor?
> > > 
> > > 73
> > > Greg K9ZM
> > > 
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