> The pitch of my old wood propeller which I am retiring is given
in
     > inches, while my new Warp Drive uses degrees to set pitch. No
     > reference
     > to inches.
     > What is the relationship between the two methods of
measurement?
     > Can you direct me to reference material (for the layman)?
     > Yvon
     >
     > Good question.
     >
     > --
     > Paul Lamar ...No rotor no motor.
     >

    I suggest you call Warp drive with your engine/airspeed/aircraft
    imfo. I was advised to set my prop
    to about 12 degrees...It is now set to 11.5 degrees ! Adjust
    the prop in VERY small increments...
    ,5 degrees or less.If you learn how to correlate degrees
    to pitch please let me know : ))
    Charles in south Mississippi

In order to figure out pitch in inches, you need to know the diameter
of
the prop. Think of it like this- the prop is turning through a medium
where there is no slippage. One revolution of the prop pulls (or
pushes)
the airplane how far forward (in inches)?

Get out your trigonometry textbook.

Not  trying to be  a smartass, but I'd have to dust mine off to give
you
an answer, if I knew your prop diameter, but I'm at work and don't
have
it here.

Brian Trubee

Thank you all people. I will keep you informed of my progress in
installation and testing.
Yvon.

Hi Yvon,

There is more to a prop than just pitch. Twist is also important.
Here are three examples. You need to add a few degrees
to these numbers to generate thrust.
Note that even at 100 MPH design speed a prop
needs  55 degrees twist. Unfortunately the Warp Drive blade has
very little twist. As speed increases the twist angle also
increases slightly. The IVO prop is also defective
in this regard with very little angle of attack near the hub.

RPM = 2700  MPH = 100
 Radius  Tang FPS Tang MPH    Angle
    3.00     71       48.2     64.3
    6.00    141       96.3     46.1
    9.00    212      144.5     34.7
   12.00    283      192.7     27.4
   15.00    353      240.9     22.5
   18.00    424      289.0     19.1
   21.00    495      337.2     16.5
   24.00    565      385.4     14.5
   27.00    636      433.5     13.0
   30.00    707      481.7     11.7
   33.00    777      529.9     10.7
   36.00    848      578.0      9.8

RPM = 2700  MPH = 150
 Radius  Tang FPS Tang MPH    Angle
    3.00     71       48.2     72.2
    6.00    141       96.3     57.3
    9.00    212      144.5     46.1
   12.00    283      192.7     37.9
   15.00    353      240.9     31.9
   18.00    424      289.0     27.4
   21.00    495      337.2     24.0
   24.00    565      385.4     21.3
   27.00    636      433.5     19.1
   30.00    707      481.7     17.3
   33.00    777      529.9     15.8
   36.00    848      578.0     14.5

RPM = 2700  MPH = 200
 Radius  Tang FPS Tang MPH    Angle
    3.00     71       48.2     76.5
    6.00    141       96.3     64.3
    9.00    212      144.5     54.1
   12.00    283      192.7     46.1
   15.00    353      240.9     39.7
   18.00    424      289.0     34.7
   21.00    495      337.2     30.7
   24.00    565      385.4     27.4
   27.00    636      433.5     24.8
   30.00    707      481.7     22.5
   33.00    777      529.9     20.7
   36.00    848      578.0     19.1

OPEN "pitch100.dat" FOR OUTPUT AS #1
CLS
RPM = 2700
PRINT #1, "RPM ="; RPM;
PRINT #1, " MPH = 100"
PRINT #1, " Radius  Tang FPS Tang MPH    Angle"
FOR radius = .25 TO 3 STEP .25
RadiusInch = radius * 12
PRINT #1, USING "#####.##"; RadiusInch;
TangVelFPS = (6.28 * radius * RPM) / 60
PRINT #1, USING "#######"; TangVelFPS;
TangVelMPH = (TangVelFPS * 60) / 88
PRINT #1, USING "#########.#"; TangVelMPH;
tan1 = 100 / TangVelMPH
angleRAD = ATN(tan1)
angleDeg = (angleRAD * 57.295)
PRINT #1, USING "#######.#"; angleDeg
NEXT
CLOSE
SHELL "more < pitch100.dat"
SYSTEM


Paul Lamar ...No rotor no motor.

The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://www.rotaryeng.net
Copyright 1998-2006 All world wide rights reserved.