Today's Message Index:
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0. 12:16 AM - No "Black Friday" For List Fund Raiser... (Matt Dralle)
1. 04:25 AM - Prop pitch (Jeffrey Dill)
2. 05:46 AM - Re: Prop pitch (Tom Jones)
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| Subject: | No "Black Friday" For List Fund Raiser... |
Dear Listers,
Curiously, even though the number of List subscriptions are significantly up this
year, support during this year's Fund Raiser is still substantially behind
last year. There are only a couple more days left in November and the end of
the Fund Raiser is quickly approaching.
I have always preferred a non-commercial List experience as many, many members
have also expressed that they do as well. However, if the yearly fund raiser
cannot generate sufficient funds to keep the bills paid, other sources of income
might be required including some sort of advertising. Please don't let that
happen! Your personal Contribution of $20 or $30 goes a long ways to keeping
the operation a float.
Please make sure your name is on this year's List of Contributors published in
December.
The Contribution site is secure, quick, and easy:
http://www.matronics.com/contribution
Or, drop a personal check in the mail to:
Matt Dralle / Matronics
581 Jeannie Way
Livermore CA 94550
USA
Thank you in advance for your support!
Matt Dralle
Matronics Email List and Forum Administrator
Message 1
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You guys probably read why I changed my GSC prop on a different thread. Now I want
to know how much pitch is too much? I just read a comment on a thread of similar
title from Chris:
"... when I reached about 12 deg, it overloaded the engine and had very poor performance.
11-11.5 was my happy spot."
My question now is how much pitch is too much? I want a cruise prop because I
operate from long runways and climb performance is not critical, so I tried to
match the pitch of my previous prop. The max RPM I saw with the old one was about
6500 on my 503. I liked it because I didn't have to worry about exceeding
redline RPM, had plenty of climb performance and cruise speeds approaching the
the yellow arc.
Now I have installed an identical prop, but new. I did an engine run and saw
6500 RPM at full throttle. At that point I double-checked the torque, saftied
the bolts and flew. In flight, the max RPM that I saw was maybe 6100. I still
had plenty of performance in both climb and cruise. The engine was not running
hot or anything (OAT approx 4C/40F). I am not seeing the "very poor performance"
that Chris mentions. But the full throttle RPM was so much less than Rotax
red-line of 6800 that I am worried about unintended consequences.
I will probably reduce the pitch some more, unless somebody smarter than me
tells me there is no problem operating it this way.
--------
Jeff Dill
Model 2
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=321191#321191
Message 2
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Jeffrey Dill wrote:
> Now I have installed an identical prop, but new. I did an engine run and saw
6500 RPM at full throttle. At that point I double-checked the torque, saftied
the bolts and flew. In flight, the max RPM that I saw was maybe 6100. I still
had plenty of performance in both climb and cruise. The engine was not running
hot or anything (OAT approx 4C/40F). I am not seeing the "very poor performance"
that Chris mentions. But the full throttle RPM was so much less than Rotax
red-line of 6800 that I am worried about unintended consequences.
Jeffrey, my advice is to recheck the pitch to be sure a blade didn't slip after
you checked the static RPM. RPM at full throttle in level flight should be higher
than RPM at static full throttle.
If you find the pitch is okay then check both static RPM at full throttle and max
RPM in level flight full throttle again. Your static and in flight RPM's seem
to be reversed.
For what its worth here's my number's with a 503 and a 72 inch warp two blade prop,
Classic 4. Static 6200, level flight full throttle 6600. On a 40 degree
day at 2000 msl I get close to 800 feet per minute climb and 85 mph cruise at
6000 rpm.
--------
Tom Jones
Classic IV
503 Rotax, 72 inch Two blade Warp
Ellensburg, WA
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=321193#321193
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