Today's Message Index:
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1. 07:02 AM - Re: Allegro 80 HP Woodcomp Pitch setting (TIM MOSES)
2. 07:46 PM - Re: Allegro 80 HP Woodcomp Pitch setting (hgmckay@bellsouth.net)
Message 1
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| Subject: | Re: Allegro 80 HP Woodcomp Pitch setting |
Hugh,
I just got an email from the Australian Allegro/Woodcomp dealer and he
said that the blade pitch is measured at "1/3 of the blade length from
the tip". I thought it was customary to use the 75% blade span (ie. 1/4
of the blade length from the tip). So my question is what distance is
this 14 or 15 degrees measured at?
The following is the adjustment message I recieved from Michael Coats:
setting up the propeller is no big deal but it must be done properly.
forget the recommendations above, there is only one way to set the
propeller and the instructions follow. Please note I am the Woodcomp
certified service centre from Australia and New Zealand so I can tell
you with certainty that the following information is correct.
The correct distance the setting the blade measurement with just about
every propeller ever manufactured is ***one third*** of the blade length
in
from the blade tip. You will see in the attached photographs I have
made a very small T square which on the propeller I am using is 180 mm
long, yours will be similar.
In a pictures shown I am using a warp drive propeller protract which is
probably the most common unit out there, is extremely cheap (approximate
we $20) and will last a lifetime of normal use provided you don't drop
it and break it.
Step one, make sure the propeller blade is horizontal, if it is not
horizontal get it is close to horizontal is you can and using a piece of
wood or a broomstick or something like that marked the distance from the
propeller leading edge to the ground and make sure that all of the other
adjustments are made in this exact same position otherwise you will get
varying blade angles. So firstly to set the propeller horizontal and
then using the little T square position the propeller protract one third
of the way up the propeller and take your adjustment. We mainly have
cruise settings on our propeller and these follow below....
80hp 18 degrees
100 hp 21 degrees
If you want to get a bit more climb performance out of it I would
suggest initially going approximately 1 1/2 degrees finer pitch, so for
example on the 80 hp engine I would start at about 16.5=B0 or
thereabouts
than it is a simple matter of adjusting each of the three blades on the
propeller to get them all identical. Tighten up all the bolts and
recheck after everything has been tightened just to make sure that
nothing has moved. You can leave the propeller spinner off if you wish
and go for a fly making sure that the performance and blade angles suit
your needs. If you find your engine is over revving or you are using
too many revs to your desired cruise speed simply course in the
propeller up so go from 16.5=B0 to approximately 17.5=B0 and so on.
On most of these propellers 1=B0 of blade movement makes approximately
200
rpm difference as a general rule of thumb so if your aircraft is
readying 400 rpm too high then you can make a adjustment of 2=B0 to
bring
it back to the desired rpm. Please let me know if you have any
additional questions, kind regards Michael
--
With regards, Michael Coates
Company Director X-Air Australia
Gold Coast, Australia.
Tim
----- Original Message -----
From: hgmckay@bellsouth.net
To: allegro-list@matronics.com
Sent: Tuesday, October 30, 2007 8:34 PM
Subject: Re: Allegro-List: Allegro 80 HP Woodcomp Pitch setting
Tim:
I agree, the 23.5 degrees is too much. I went through a series of
emails on the rotaxengines-list@matronics.com back in October 2006 on
this same subject. Go to that forum and look at the archived emails on
the subject. I finally settled at 15 degrees which gave me 5100 rpm
(static). If you ask Fantasy Air USA (Matt Smith) he will tell you they
set all their props at 14 degrees. You will get various opinions on this
subject, but 23.5 degres is certainly too much, and I believe every one
will agree on that. At least I hope so!!
Hugh McKay in NC
Allegro 2000
Rotax 912 UL
WoodComp Three Blade (Klassic 160/3/R
N661WW
-------------- Original message from "TIM MOSES"
<tcmoses@earthlink.net>: --------------
What would be a good pitch setting for climb on an Allegro with the
80 HP Rotax and the Woodcomp prop? The previously reccomended pitch of
23.5 degrees at 7.875" from the tip seems like it is way too much.
Message 2
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| Subject: | Re: Allegro 80 HP Woodcomp Pitch setting |
Tim:
Who am I to question the Australian Authorized WoodComp Service Center! It is interesting
however to note that the Woodcomp Manual (at least the one I have)
shows that the pitch angle should be measured 60 mm from the blade tip. For a
1600 mm diameter propeller (800 mm blade length from center of hub) this is 92.5%
of the blade length. The little diagram shows that the blade pitch at this
point can vary from 6 degrees to 17 degrees. All this is meaningless! Remember,
the blade twist changes through out the length of the blade. I do not know
why most prop manufacturers use the 75% length, and neither do I know why Mr.
Coats uses 60% of the blade length (i.e 30% in from the blade tip). His procedure
for setting the pitch is correct and I fully agree with it, but why 30% in
from the tip vs. 25% in , I haven't a clue! Use either one, and then do your
static test runs and adjust the pitch to get the max static rpm you desire without
exceeding the Rotax limit.
I do know this, you will have to choose what pitch you want for the engine performance
you desire. Pitch angle is a trade off between high performance on climb
out vs. most efficient cruise speed in horizontal flight. You will have to
decide what you want, and set the pitch, do the static tests, and then fly the
plane and find out if it performs the way you want it to. In the air check the
cruise rpm at WOT. Hopefully you will be around 5500 rpm at WOT. If not come
back, land and adjust the prop pitch accordingly (lower pitch angle = better
climb out performance, higher pitch angle = better rpm cruise speed.
I will note that I had a difficult time adjusting the pitch on my Allegro (I used
the same method Mr. Coats described with the prop on the airplane). The blades
would not rotate smoothly in the hub with the bolts loosened. They would slip
and seize making it very difficult to get the bubble in the Warp drive protractor
exactly in the middle. Hope you don't have the same dificulty. I would
love to have a jig to do this on a level table rather than on the plane. Good
Luck.
Hugh McKay
-------------- Original message from "TIM MOSES" <tcmoses@earthlink.net>: --------------
Hugh,
I just got an email from the Australian Allegro/Woodcomp dealer and he said that
the blade pitch is measured at "1/3 of the blade length from the tip". I thought
it was customary to use the 75% blade span (ie. 1/4 of the blade length
from the tip). So my question is what distance is this 14 or 15 degrees measured
at?
The following is the adjustment message I recieved from Michael Coats:
setting up the propeller is no big deal but it must be done properly.
forget the recommendations above, there is only one way to set the
propeller and the instructions follow. Please note I am the Woodcomp
certified service centre from Australia and New Zealand so I can tell
you with certainty that the following information is correct.
The correct distance the setting the blade measurement with just about
every propeller ever manufactured is ***one third*** of the blade length in
from the blade tip. You will see in the attached photographs I have
made a very small T square which on the propeller I am using is 180 mm
long, yours will be similar.
In a pictures shown I am using a warp drive propeller protract which is
probably the most common unit out there, is extremely cheap (approximate
we $20) and will last a lifetime of normal use provided you don't drop
it and break it.
Step one, make sure the propeller blade is horizontal, if it is not
horizontal get it is close to horizontal is you can and using a piece of
wood or a broomstick or something like that marked the distance from the
propeller leading edge to the ground and make sure that all of the other
adjustments are made in this exact same position otherwise you will get
varying blade angles. So firstly to set the propeller horizontal and
then using the little T square position the propeller protract one third
of the way up the propeller and take your adjustment. We mainly have
cruise settings on our propeller and these follow below....
80hp 18 degrees
100 hp 21 degrees
If you want to get a bit more climb performance out of it I would
suggest initially going approximately 1 1/2 degrees finer pitch, so for
example on the 80 hp engine I would start at about 16.5 or thereabouts
than it is a simple matter of adjusting each of the three blades on the
propeller to get them all identical. Tighten up all the bolts and
recheck after everything has been tightened just to make sure that
nothing has moved. You can leave the propeller spinner off if you wish
and go for a fly making sure that the performance and blade angles suit
your needs. If you find your engine is over revving or you are using
too many revs to your desired cruise speed simply course in the
propeller up so go from 16.5 to approximately 17.5 and so on.
On most of these propellers 1 of blade movement makes approximately 200
rpm difference as a general rule of thumb so if your aircraft is
readying 400 rpm too high then you can make a adjustment of 2 to bring
it back to the desired rpm. Please let me know if you have any
additional questions, kind regards Michael
--
With regards, Michael Coates
Company Director X-Air Australia
Gold Coast, Australia.
Tim
----- Original Message -----
From: hgmckay@bellsouth.net
Sent: Tuesday, October 30, 2007 8:34 PM
Subject: Re: Allegro-List: Allegro 80 HP Woodcomp Pitch setting
Tim:
I agree, the 23.5 degrees is too much. I went through a series of emails on the
rotaxengines-list@matronics.com back in October 2006 on this same subject. Go
to that forum and look at the archived emails on the subject. I finally settled
at 15 degrees which gave me 5100 rpm (static). If you ask Fantasy Air USA (Matt
Smith) he will tell you they set all their props at 14 degrees. You will
get various opinions on this subject, but 23.5 degres is certainly too much, and
I believe every one will agree on that. At least I hope so!!
Hugh McKay in NC
Allegro 2000
Rotax 912 UL
WoodComp Three Blade (Klassic 160/3/R
N661WW
-------------- Original message from "TIM MOSES" <tcmoses@earthlink.net>: --------------
What would be a good pitch setting for climb on an Allegro with the 80 HP Rotax
and the Woodcomp prop? The previously reccomended pitch of 23.5 degrees at 7.875"
from the tip seems like it is way too much.
href="http://www.matronics.com/Navigator?Allegro-List">http://www.matronics.com/Navigator?Allegro-List
href="http://forums.matronics.com">http://forums.matronics.com
<html>
<!-- BEGIN WEBMAIL STATIONERY -->
<head></head>
<body>
<!-- WEBMAIL STATIONERY noneset -->
<DIV></DIV>
<P>Tim:</P>
<P> </P>
<P>Who am I to question the Australian Authorized WoodComp Service Center! It is
interesting however to note that the Woodcomp Manual (at least the one I have)
shows that the pitch angle should be measured 60 mm from the blade tip. For
a 1600 mm diameter propeller (800 mm blade length from center of hub) this is
92.5% of the blade length. The little diagram shows that the blade pitch at this
point can vary from 6 degrees to 17 degrees. All this is meaningless! Remember,
the blade twist changes through out the length of the blade. I do not know
why most prop manufacturers use the 75% length, and neither do I know why Mr.
Coats uses 60% of the blade length (i.e 30% in from the blade tip). His procedure
for setting the pitch is correct and I fully agree with it, but why 30%
in from the tip vs. 25% in , I haven't a clue! Use either one, and then do your
static test runs and adjust the pitch to get the max static rpm you desire
without exceeding the Rotax limit.</P>
<P> </P>
<P>I do know this, you will have to choose what pitch you want for the engine performance
you desire. Pitch angle is a trade off between high performance on
climb out vs. most efficient cruise speed in horizontal flight. You will have
to decide what you want, and set the pitch, do the static tests, and then fly
the plane and find out if it performs the way you want it to. In the air check
the cruise rpm at WOT. Hopefully you will be around 5500 rpm at WOT. If not come
back, land and adjust the prop pitch accordingly (lower pitch angle = better
climb out performance, higher pitch angle = better rpm cruise speed.</P>
<P> </P>
<P>I will note that I had a difficult time adjusting the pitch on my Allegro (I
used the same method Mr. Coats described with the prop on the airplane). The
blades would not rotate smoothly in the hub with the bolts loosened. They would
slip and seize making it very difficult to get the bubble in the Warp drive
protractor exactly in the middle. Hope you don't have the same dificulty. I would
love to have a jig to do this on a level table rather than on the plane. Good
Luck.</P>
<P> </P>
<P>Hugh McKay<BR></P>
<BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px
solid">-------------- Original message from "TIM MOSES" <tcmoses@earthlink.net>:
-------------- <BR><BR><!-- BEGIN WEBMAIL STATIONERY -->
<META content="MSHTML 6.00.6000.16544" name=GENERATOR>
<DIV><FONT face=Arial size=2>Hugh,</FONT></DIV>
<DIV><FONT face=Arial size=2>I just got an email from the Australian Allegro/Woodcomp
dealer and he said that the blade pitch is measured at "1/3 of the blade
length from the tip". I thought it was customary to use the 75% blade
span (ie. 1/4 of the blade length from the tip). So my question is what
distance is this 14 or 15 degrees measured at?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>The following is the adjustment message I recieved
from Michael Coats:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV>setting up the propeller is no big deal but it must be done properly. <BR>forget
the recommendations above, there is only one way to set the <BR>propeller
and the instructions follow. Please note I am the Woodcomp <BR>certified
service centre from Australia and New Zealand so I can tell <BR>you with certainty
that the following information is correct.<BR><BR>The correct distance
the setting the blade measurement with just about <BR>every propeller ever manufactured
is ***one third*** of the blade length in <BR>from the blade tip.
You will see in the attached photographs I have <BR>made a very small T
square which on the propeller I am using is 180 mm <BR>long, yours will be similar.<BR><BR>In
a pictures shown I am using a warp drive propeller protract which
is <BR>probably the most common unit out there, is extremely cheap (approximate
<BR>we $20) and will last a lifetime of normal use provided you don't drop
<BR>it and break it.<BR><BR>Step one, make sure th
e prop
eller blade is horizontal, if it is not <BR>horizontal get it is close to horizontal
is you can and using a piece of <BR>wood or a broomstick or something like
that marked the distance from the <BR>propeller leading edge to the ground
and make sure that all of the other <BR>adjustments are made in this exact same
position otherwise you will get <BR>varying blade angles. So firstly to
set the propeller horizontal and <BR>then using the little T square position
the propeller protract one third <BR>of the way up the propeller and take your
adjustment. We mainly have <BR>cruise settings on our propeller and these
follow below....<BR><BR>80hp 18 degrees<BR><BR>100 hp 21 degrees<BR><BR>
If you want to get a bit more climb performance out of it I would <BR>suggest
initially going approximately 1 1/2 degrees finer pitch, so for <BR>example
on the 80 hp engine I would start at about 16.5 or thereabouts <BR>than it
is a simple matter of adjusting each of the three bl
ades o
rtain
<DIV><FONT face=Arial size=2>Tim</FONT></DIV>
<BLOCKQUOTE dir=ltr style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT:
5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B> <A title=hgmckay@bellsouth.net href="mailto:hgmckay@bellsouth.net">hgmckay@bellsouth.net</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=allegro-list@matronics.com href="mailto:allegro-list@matronics.com">allegro-list@matronics.com</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, October 30, 2007 8:34 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Allegro-List: Allegro 80 HP Woodcomp
Pitch setting</DIV>
<DIV><BR></DIV><!-- WEBMAIL STATIONERY noneset -->
<DIV></DIV>
<P> </P>
<P>Tim: </P>
<P>I agree, the 23.5 degrees is too much. I went through a series of emails on the <A href="mailto:rotaxengines-list@matronics.com">rotaxengines-list@matronics.com</A> back in October 2006 on this same subject. Go to that forum and look at the archived emails on the subject. I finally settled at 15 degrees which gave me 5100 rpm (static). If you ask Fantasy Air USA (Matt Smith) he will tell you they set all their props at 14 degrees. You will get various opinions on this subject, but 23.5 degres is certainly too much, and I believe every one will agree on that. At least I hope so!!</P>
<P> </P>
<P>Hugh McKay in NC</P>
<P>Allegro 2000</P>
<P>Rotax 912 UL</P>
<P>WoodComp Three Blade (Klassic 160/3/R</P>
<P>N661WW<BR></P>
<BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px
solid">-------------- Original message from "TIM MOSES" <tcmoses@earthlink.net>:
-------------- <BR><BR>
<META content="MSHTML 6.00.6000.16544" name=GENERATOR>
<STYLE></STYLE>
<DIV><FONT face=Arial size=2>What would be a good pitch setting for climb on an
Allegro with the 80 HP Rotax and the Woodcomp prop? The previously reccomended
pitch of 23.5 degrees at 7.875" from the tip seems like it is way too
much.</FONT></DIV><PRE><B><FONT face="courier new,courier" size=2 color000000?>
</B></FONT></PRE></BLOCKQUOTE><!-- END WEBMAIL STATIONERY --><PRE><B><FONT face="courier
new,courier" color=#000000 size=2>
href="http://www.matronics.com/Navigator?Allegro-List">http://www.matronics.com/Navigator?Allegro-List</A>
href="http://forums.matronics.com">http://forums.matronics.com</A>
</B></FONT></PRE></BLOCKQUOTE><PRE><B><FONT face="courier new,courier" size=2 color000000?>
</B></FONT></PRE></BLOCKQUOTE>
<!-- END WEBMAIL STATIONERY -->
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