Fw: Re: KR> Prop Tracking

[joe.kr2s.buil...@juno.com]

Hope this is useful to both groups:I am going to expand this conversation a 
little to the whole installation practice which seem to me to be a common sense 
approach to mounting a wooden prop and maybe even a metal one. First use the 
star pattern to tighten the prop bolts as that well keep the prop from crushing 
on one side first. Second using the star pattern, torque in increments to the 
final torque setting. I usually go around 3 times to achieve the final torque 
increasing by 1/3 of the total final value each time around the pattern. I also 
use a torque wrench that is in inch/pounds to be more precise about the final  
torque. One other item for safety and ease is to remove the spark plugs, ( you 
then know the engine won't kick and for tracking you won't be fighting the 
compression to turn the prop and not have the plane move for accuracy, tip 
compliments of WW)I have been told that a substantial number of props 
returned to manufacturer's have been over torqued and crushed into the prop hub 
(repairable but not to be ignored). It is my understanding that there should 
not be crush marks (indentations) when a prop is installed properly. My opinion 
is the shimming that Oscar describes would be the next progression to get a 
prop in track. I have never had a Sensenich CNC'd prop out of track mounting it 
this way. This is not a difficult process, just needs a procedure followed 
to achieve good results.Hopefully your results don't vary,Joe 
Horton,Coopersburg, Pa.
-- Forwarded Message --
From: "Mark Jones" 

- Original Message - 
From: "Dan Heath" 


I have a Sensenich prop and it tracks 3/16" different from tip to tip. I
have always used Sterba props in the past and have never had this problem.
So, what to do to correct this? It seems like a defect in the prop, but
maybe not.


Dan,
Torque the bolts on the blade side which is fartherest forward by one foot 
pound at a time till the tips even out. It should only take one or two 
additional pounds to even it out.


Mark Jones (N886MJ)
Stevens Point, WI

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KR> Prop Tracking

[Oscar Zuniga]

As Jeff pointed out, this kind of tracking variation is common on the small 
Continentals.  Jeff helped me take out about 1/8" of tracking difference on my 
A65 with taper shaft prop hub and Hegy wood prop.  I was astounded to see that 
he took out the tracking error by using a shim made from nothing more than a 
piece of paper just slightly heavier than ordinary copier paper, between the 
prop and hub, spanning the space between two of the prop bolts.  I believe it 
reduced the difference to less than 1/32" on a 72" prop.

I now have an A75 on my Piet and it has a flanged prop hub.  Same problem... 
when I checked prop tracking at annual, the Culver wood prop was out of track 
by a bit more than 1/8".  Using Jeff's trick, it shimmed out to nearly zero.  
Following that up with a DynaVibe balance and a small counterweight out in 
front, not only does the prop track almost absolutely true, the engine/prop 
combo is super-smooth.  Makes a difference. 

PS, in smooth air and level flight in cruise, I could feel the very slight 
vibration when the prop was tracking with one blade 1/8" out, and that's with 
an engine that turns about 2250 at cruise.  I don't know what that translates 
to with a shorter prop, 1000 RPM higher speed, and 1/4" out of track.

Oscar Zuniga
Air Camper NX41CC "Scout"
Flying Squirrel N2069Z "Rocket"
Medford, OR

website at http://www.flysquirrel.net

KR> Prop Tracking

[Glenn Martin]

According the Murphy's law..the prop is straight, the rest of the plane 
is bent.
-- 
Glenn Martin,
KR2 N1333A,
Biloxi, MS

KR> Prop Tracking

[Dan Heath]

Sensenich  allows 1/8"

See N64KR at http://KRBuilder.org - Then click on the pics 
See you at the 2012 - KR Gathering in Mt. Vernon, Il – MVN – 40th
Anniversary
There is a time for building and it never seems to end.
Daniel R. Heath - Lexington, SC


-Original Message-


The specs for the McCauley 7447 on my Luscombe allow up to 1/4" tracking 
error, so you may be OK. Or you may want to have it overhauled.

KR> Prop Tracking

[John Martindale]

Maybe check hub run out to be sure there is no problem there first??

John Martindale
29 Jane Circuit
Toormina NSW 2452
Australia

ph:61 2 6658 4767
m:0403 432179
email:john_martind...@bigpond.com

KR> Prop Tracking

[Jeff Scott]

1/4" error in prop tracking will cause a pretty significant vibration.

- Original Message -
From: R. Lee Jarvis
Sent: 11/26/11 04:43 PM
To: KRnet
Subject: Re: KR> Prop Tracking

 The specs for the McCauley 7447 on my Luscombe allow up to 1/4" tracking 
error, so you may be OK. Or you may want to have it overhauled.

KR> Prop Tracking

[Jeff Scott]

Make a note of which tip is leading, then swap the prop 180 degrees on the hub. 
If the same tip is leading, it's a prop issue. If the other tip is leading, 
it's a hub issue. If it is a new Sensinich prop, I expect they will warranty 
the prop. If it's a hub issue, you can either tear into the engine/hub to find 
out why it isn't true, or you can shim the prop.

 In either case, it is legitimate to correct the tracking by shimming between 
the prop and hub to correct the tracking. This is a very common problem on the 
older Continental engines with taper crankshafts. I have yet to see a 
tapershaft hub adapter that turns true and doesn't need to have the prop 
shimmed. The point is that shimming the prop to true up the tracking is a 
common and legitimate practice.

 -Jeff Scott
 Los Alamos, NM

- Original Message -

 I have a Sensenich prop and it tracks 3/16" different from tip to tip. I have 
always used Sterba props in the past and have never had this problem. So, what 
to do to correct this? It seems like a defect in the prop, but maybe not. 
Daniel R. Heath - Lexington, SC ___ Search 
the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe 
from KRnet, send a message to krnet-le...@mylist.net please see other KRnet 
info at http://www.krnet.org/info.html

KR> Prop Tracking

[Mark Jones]

I forgot to mention.
NOTE: Do not exceed the range specified on the prop.



- Original Message - 
From: "Mark Jones" <flyk...@charter.net>
To: "KRnet" <kr...@mylist.net>
Sent: Saturday, November 26, 2011 5:46 PM
Subject: Re: KR> Prop Tracking



- Original Message - 
From: "Dan Heath" <da...@windstream.net>


I have a Sensenich prop and it tracks 3/16" different from tip to tip. I
have always used Sterba props in the past and have never had this problem.
So, what to do to correct this? It seems like a defect in the prop, but
maybe not.


Dan,
Torque the bolts on the blade side which is fartherest forward by one foot 
pound at a time till the tips even out. It should only take one or two 
additional pounds to even it out.


Mark Jones (N886MJ)
Stevens Point, WI
E-mail: flyk...@charter.net
Web: www.flykr2s.com





___
Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp
to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
please see other KRnet info at http://www.krnet.org/info.html

KR> Prop Tracking

[Mark Jones]

- Original Message - 
From: "Dan Heath" 


I have a Sensenich prop and it tracks 3/16" different from tip to tip. I
have always used Sterba props in the past and have never had this problem.
So, what to do to correct this? It seems like a defect in the prop, but
maybe not.


Dan,
Torque the bolts on the blade side which is fartherest forward by one foot 
pound at a time till the tips even out. It should only take one or two 
additional pounds to even it out.


Mark Jones (N886MJ)
Stevens Point, WI
E-mail: flyk...@charter.net
Web: www.flykr2s.com

KR> Prop Tracking

[R. Lee Jarvis]

The specs for the McCauley 7447 on my Luscombe allow up to 1/4" tracking 
error, so you may be OK. Or you may want to have it overhauled.


- Original Message - 
From: "Dan Heath" <da...@windstream.net>
To: "'KRnet'" <kr...@mylist.net>
Sent: Saturday, November 26, 2011 6:21 PM
Subject: KR> Prop Tracking


>I have a Sensenich prop and it tracks 3/16" different from tip to tip.  I
> have always used Sterba props in the past and have never had this problem.
> So, what to do to correct this?  It seems like a defect in the prop, but
> maybe not.
>
>
>
> See N64KR at  <http://krbuilder.org/> http://KRBuilder.org - Then click on
> the pics
>
> See you at the 2012 - KR Gathering in Mt. Vernon, Il - MVN - 40th
> Anniversary
>
> There is a time for building and it never seems to end.
>
> Daniel R. Heath - Lexington, SC
>
>
>
>
>
> ___
> Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
> please see other KRnet info at http://www.krnet.org/info.html 

KR> Prop Tracking

[Deems Herring]

Sensenich says 1/8" is max. See here: 
http://www.sensenich.com/files/documents/Installation_Instructions_Wood_Aircraft_Installation_1261581692.pdf.
Try removing the prop check the face of the prop and conterbores. install the 
prop 180 degrees from previous, using the above instruction and recheck 
tracking. If it is not in spec call 
Sensenich and get their input. I have always found them very helpful.



Deems





> From: da...@windstream.net
> To: kr...@mylist.net
> Date: Sat, 26 Nov 2011 18:21:33 -0500
> Subject: KR> Prop Tracking
> 
> I have a Sensenich prop and it tracks 3/16" different from tip to tip.  I
> have always used Sterba props in the past and have never had this problem.
> So, what to do to correct this?  It seems like a defect in the prop, but
> maybe not.
> 
>  
> 
> See N64KR at  <http://krbuilder.org/> http://KRBuilder.org - Then click on
> the pics 
> 
> See you at the 2012 - KR Gathering in Mt. Vernon, Il - MVN - 40th
> Anniversary
> 
> There is a time for building and it never seems to end.
> 
> Daniel R. Heath - Lexington, SC
> 
>  
> 
>  
> 
> ___
> Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp
> to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net
> please see other KRnet info at http://www.krnet.org/info.html

KR> Prop Tracking

[Dan Heath]

I have a Sensenich prop and it tracks 3/16" different from tip to tip.  I
have always used Sterba props in the past and have never had this problem.
So, what to do to correct this?  It seems like a defect in the prop, but
maybe not.



See N64KR at   http://KRBuilder.org - Then click on
the pics 

See you at the 2012 - KR Gathering in Mt. Vernon, Il - MVN - 40th
Anniversary

There is a time for building and it never seems to end.

Daniel R. Heath - Lexington, SC