OS .46 FX prop size
Doug Dearing
I just bought the engine and a 10x6 prop that my local hobby shop
recommended.
The OS materials that came with the engine says to use a 11x6 prop. Is
this going
be be a problem? Any input would help.
Thanks,
Dougster - http://web2.airmail.net/dougster
Steven M. Ziuchkovski
In <D8F66C0F0B1C9785.7BBB32C4...@library-proxy.airnews.net> "Doug Dearing" <doug...@airmail.net> writes:
>I just bought the engine and a 10x6 prop that my local hobby shop
>recommended.
I have this engine on a Hanger 9 semi-scale Cessna, designed for a .40 size
engine. I have an 11x7 prop on the plane. It goes pretty fast, but it's hard
to get an idle low enough that the engine is stable, and the plane doesn't
move on the ground.
Steve
Donnie Vazquez
Doug Dearing wrote:
>
> I just bought the engine and a 10x6 prop that my local hobby shop
> recommended.
> this going
> be be a problem? Any input would help.
>
> Thanks,
> Dougster - http://web2.airmail.net/dougster
I've used 10x6,10x7 and 11.5x4 succesfully. 11x6 should be fine.
BTW if your plane is light (under, say 5 lbs) you'll get killer
vertical from the 11.5x4
//////////////////////////////////////////////////////////////////////
Donnie Vazquez Phone: 202-404-1298
Systems Administrator Fax: 202-404-8090
Code 7640, Naval Research Lab
Washington, D.C. 20375 Internet: vaz...@uap.nrl.navy.mil
//////////////////////////////////////////////////////////////////////
Bri Mac
Doug Dearing wrote:
I have the same engine and use a 11x7. A 10x6 made it run like crap wide
open.
Gordon McConnell
Doug Dearing wrote:
>
> I just bought the engine and a 10x6 prop that my local hobby shop
> recommended.
> The OS materials that came with the engine says to use a 11x6 prop.
Doug,
The 10x6 is a great prop for an average 40... but the 46FX has more
power than a simple 40, so if you strap the 10x6 on it, chances are
that you will end up turning the engine over a bit too fast for it's
own good. It's important to stay away from such damaging situations,
especially when the engine is new.
My "gut feel" for this engine would have been an 11x6 or 11x7 APC -
so since your instructions said to use 11x6, go for it...
Gordon.
--
To reply by email, remove the "not_" from my email id.
AMA 5765 / SFA 71071 / IMAA 21397
Always glad to share my ignorance - I've got plenty.
rocketdude
In article <33C64091.375D@not_Synopsys.COM>, gmc@not_Synopsys.COM says...
>Doug,
>
>The 10x6 is a great prop for an average 40... but the 46FX has more
>power than a simple 40, so if you strap the 10x6 on it, chances are
>that you will end up turning the engine over a bit too fast for it's
>own good. It's important to stay away from such damaging situations,
>especially when the engine is new.
>
>My "gut feel" for this engine would have been an 11x6 or 11x7 APC -
>so since your instructions said to use 11x6, go for it...
>
> Gordon.
>
Gordon is correct.
My OS .46FX turns an 11x6 Master Airscrew at 13,600 and an 11x6 Graupner at
12,500. However, an 11x7 Master Airscrew shaved off about 2000 RPM. One of
these days I'll try a 10x7 and 10x8 and see what happens.
Ben
Errol Flynn
In article <5q2un7$n16$1...@linda.teleport.com>, stev...@linda.teleport.com
says...
>
>In
<D8F66C0F0B1C9785.7BBB32C4...@library-proxy.airnews.net>
"Doug Dearing" <doug...@airmail.net> writes:
>>recommended.
>
>engine. I have an 11x7 prop on the plane. It goes pretty fast, but it's hard
>to get an idle low enough that the engine is stable, and the plane doesn't
>move on the ground.
For a pattern type plane, or one that is lighter, like an UltraSport, I use
a 10x6 for speed. On a heavier plane, I use a 11x6 or 7 for the power.
Pieter Wycoff
Doug Dearing wrote:
>
> I just bought the engine and a 10x6 prop that my local hobby shop
> recommended.
> this going
I use 10x7 APC props with my .46FX and I am VERY happy with the
performance. I thought the reccomended break in prop was a 10x7, but I
could be wrong.
Later,
Pieter
remove the xxx leading my domain name to reply...
Gerald43
>I just bought the engine and a 10x6 prop that my local hobby shop
>recommended.
This depends on if you want speed or pulling power. The OS .46 wil take
anything from a 9.5-8 to a 11-6. Larger diameters with lower pitches give
less top speed and more pulling power. Smaller diameters and more pitch
give more speed and less pulling power. A good general prop would be the
10-6 or 11-6.
Gera...@aol.com
10-year scratch builder
10-year Instructor, Western Carolina R/C
8-year Contest Director
Augustus Fink-Nottle
>>I just bought the engine and a 10x6 prop that my local hobby shop
>>recommended.
A 10x6 sounds a little too small for a 46, no? Recommended sizes for sport
flying on the OS 46FX are 10.5x6, 11x6~7, 12x6~7. Currently, I am running
12x5's and 12x4's on the 46FX and it purrrrrrrs like a kitten. Quiet too.
pip-pip,
Gussie
sfaust . com - remove spaces to email
While you may gain a very little bit in speed on the 10x6, you are
loosing a lot of torque that could increase your climbing ability
easily by two fold. I could climb about 100 yards on the 10x6 before
it started to whimper out. I tested a bunch of props (10x5 to 10x8's,
11x5 to 11x8;s, and 12x5 to 12x8's).
I finally settled in on a 11x6 or 11x7. With either of these props, I
couldn't really tell any speed difference, although I do know I lost
some. But if I can't really see it, then it wasn't important. However,
when I went vertical, the difference was immediately noticeable. It
climbed and climbed and climbed. A reasonable trade off indeed if you
are into aerobatics, where a balance of speed and torque is important.
A not so reasonable trade off if all you do is go straight and yank
left.
On Tue, 29 Jul 1997 14:44:05 GMT, bo...@asbank.com (Bob Adkins) wrote:
>
>Gussie,
>
>I'm sure the FX is quiet and fun to use with those humongous props,
>but the FX is not making near its power potential with 12x4 and 12x5
>props. It's making about the same power as a bushing .40 with these
>props.....about 1 HP.
>
>A 10x6 will indeed extract most of the FX's HP potential, as will a
>11x5.
>
>If your airframe can take it, try the 10x6 or 11x5 and you will see a
>big power difference.
>
>Of course you may value quiet more than speed and acceleration, and
>that's fine......for girls! <Grinnin', duckin', and runnin'>
>
sfaust . com - remove spaces to email
I guess what I am saying, is this. These are the results of our hands
on testing with various props on a OS46fx mounted on a Dragon Lady and
StarDuster, both average low wing sports planes, both average in
weight. Your mileage and requirements may vary.
OS .46fx with 10x6 prop good speed, little vertical climb
OS .46fx with 11x7 prop good speed, excellent vertical climb
There was less than 200rpm change between props. The speed difference
was not noticable (certainly not 20MPH as you suggest), the vertical
climb was SIGNIFICANTLY better. For aerobatics, the OS46fx was
underpropped with a 10x6 on our planes.
In summary, test your props and use what works for you. I prefer
better vertical performance and pulling power for aerobatics. These
props work for us, on our planes.
On Wed, 30 Jul 1997 04:04:39 GMT, bo...@asbank.com (Bob Adkins) wrote:
>On Tue, 29 Jul 1997 17:33:15 GMT, sfaust @ avcomproductions . com -
>remove spaces to email (Steve Faust) wrote:
>
>
>Steve,
>
>Not sure I understand exactly what you are saying, but here's the
>facts.
>
>This data is from an Enya .45 CX, which is within 5% of the same power
>as the OS FX .46
>
>PROP-------- RPM------THRUST----SPEED--------HP
>
>10x6 13000 92 74 1.1
>12x6 9400 94 53 .83
>
>
>>While you may gain a very little bit in speed on the 10x6, you are
>>loosing a lot of torque that could increase your climbing ability
>>easily by two fold. I could climb about 100 yards on the 10x6 before
>>it started to whimper out. I tested a bunch of props (10x5 to 10x8's,
>>11x5 to 11x8;s, and 12x5 to 12x8's).
>
>I would say that 20 MPH is not just a little bit of speed difference.
>Thrust is about the same. It is very obvious that vertical will be
>about the same, but speed and acceleration is no contest.
>
>The obvious question is "why not use a properly propped .32 size
>engine if all you need is .83 HP"? It would out perform the FX .46
>with the 12x6 prop, and weigh 4 ounces less to boot.
>
> - - - - -- - - - - -
Uday Kamath
Augustus Fink-Nottle (bhur...@pilot.msu.edu) wrote:
: >>I just bought the engine and a 10x6 prop that my local hobby shop
: >>recommended.
I think12*5 is way too big, I think my engine runs best with a 10*6, it doesn't
puurrr...it roars, thats what it should do.
_Uday
<kam...@expert.cc.purdue.edu>
Rocketdude
In article <33e0fe2b...@194.25.158.130>, bo...@asbank.com says...
>I'm sure the FX is quiet and fun to use with those humongous props,
>but the FX is not making near its power potential with 12x4 and 12x5
>props. It's making about the same power as a bushing .40 with these
>props.....about 1 HP.
>
>A 10x6 will indeed extract most of the FX's HP potential, as will a
>11x5.
>
>If your airframe can take it, try the 10x6 or 11x5 and you will see a
>big power difference.
>
>Of course you may value quiet more than speed and acceleration, and
>that's fine......for girls! <Grinnin', duckin', and runnin'>
>
>
> - - - - - -- - - - - --
>
>"I bet when the neanderthal kids would make a snowman, someone would
>always end up saying, "Don't forget the thick, heavy brows." Then they
>would all get embarrassed because they remembered they had the big
>hunky brows too, and they'd get mad and eat the snowman."
>
>Bob
>
>"From the Heart of Cajun Country"
>
>ICQ# 1630624
We are talking about the .46 FX not the .40 FX, right?
I'm getting 13,600+ RPM on mine with standard muffler and a 11x6 Master
Airscrew, which works out to 1.578 HP and 77.28 MPH, theoretical.
In order to see the same "HP potential" with a 10x6 I would need to turn it at
about 15,500 RPM, pushing it a bit. If I was able to turn an 11x5 at 14,500
RPM I would realize about 1.59 HP but a speed of only 68 MPH, theoretical.
All of this, along with a lot of playing around, leads me to believe that an
11x6 is the best all around prop for a stock .46 FX, IMHO.
However, mileage does vary with different prop brands/styles.
------------------------------
Plagiarized "Deep Thought" Here
Ben
From the Land of Oz
Gordon McConnell
Why stop there ?? If noise is what you like, run an 8x4 and listen to
it scream... after all, speed is directly proportional to noise,
is it not ?
And if you believe that, please contact me - I have a bridge that
I'd like to sell you !! ;-D
Gordon
--
To reply by email, remove the anti-spam "not_" from my email id.
Rocketdude
In article <33e2b77d...@194.25.158.130>, bo...@asbank.com says...
>
>
>This data is from an Enya .45 CX, which is within 5% of the same power
>as the OS FX .46
>
>PROP-------- RPM------THRUST----SPEED--------HP
>
>10x6 13000 92 74 1.1
>12x6 9400 94 53 .83
>
>
>>While you may gain a very little bit in speed on the 10x6, you are
>>loosing a lot of torque that could increase your climbing ability
>>easily by two fold. I could climb about 100 yards on the 10x6 before
>>it started to whimper out. I tested a bunch of props (10x5 to 10x8's,
>>11x5 to 11x8;s, and 12x5 to 12x8's).
>
>I would say that 20 MPH is not just a little bit of speed difference.
>Thrust is about the same. It is very obvious that vertical will be
>about the same, but speed and acceleration is no contest.
>
>The obvious question is "why not use a properly propped .32 size
>engine if all you need is .83 HP"? It would out perform the FX .46
>with the 12x6 prop, and weigh 4 ounces less to boot.
>
Based on your data above, I would say the Enya .45 CX is not even close to the
.46 FX.
Ben
Jim,Susan, Stephanie or Patrick Morgan
Gordon McConnell <gmc@not_Synopsys.COM> wrote in article
<33DF9A76.75F6@not_Synopsys.COM>...
> Uday Kamath wrote:
> >
> > Augustus Fink-Nottle (bhur...@pilot.msu.edu) wrote:
> > : >>I just bought the engine and a 10x6 prop that my local hobby shop
> > : >>recommended.
> >
> > : A 10x6 sounds a little too small for a 46, no?
> > I think12*5 is way too big, I think my engine runs best with a 10*6, it
doesn't
> > puurrr...it roars, thats what it should do.
> >
>
> Why stop there ?? If noise is what you like, run an 8x4 and listen to
> it scream... after all, speed is directly proportional to noise,
> is it not ?
Prop guidelines are just that-guidelines. It depends so much on the engine
and the airplane. You just have to try a couple different sizes.
For example - I have an old Fox .40 standard on a Gremlin. With an APC
10-6, it will barely hand launch without hilling the ground. Put on a 9-6
and it jumps away, and will keep up with the best of the other speed demons
in the club.
Put the same engine in a trainer, and it will be happy with a 10-6 or 11-5
or whatever.
Borrow or buy some props. If you can't tell the difference, it doesn't
matter. If you can tell, do what works. (now that is a real profound
statement, or something)
Bob Adkins
On Wed, 30 Jul 1997 12:18:09 GMT, sfaust @ avcomproductions . com -
remove spaces to email (Steve Faust) wrote:
>I guess what I am saying, is this. These are the results of our hands
>on testing with various props on a OS46fx mounted on a Dragon Lady and
>StarDuster, both average low wing sports planes, both average in
>weight. Your mileage and requirements may vary.
>
> OS .46fx with 10x6 prop good speed, little vertical climb
> OS .46fx with 11x7 prop good speed, excellent vertical climb
>
>There was less than 200rpm change between props. The speed difference
>was not noticable (certainly not 20MPH as you suggest), the vertical
>climb was SIGNIFICANTLY better. For aerobatics, the OS46fx was
>underpropped with a 10x6 on our planes.
Um.....go back to my original post. I was speaking of 12" props where
there is a 20 MPH difference.
Some 11 inchers are nearly perfect for the FX .46, namely the 11x6.
Bob Adkins
On Wed, 30 Jul 1997 12:48:06 -0700, Gordon McConnell
<gmc@not_Synopsys.COM> wrote:
>> I think12*5 is way too big, I think my engine runs best with a 10*6, it doesn't
>> puurrr...it roars, thats what it should do.
>>
>
>Why stop there ?? If noise is what you like, run an 8x4 and listen to
>it scream... after all, speed is directly proportional to noise,
>is it not ?
>
>And if you believe that, please contact me - I have a bridge that
>I'd like to sell you !! ;-D
Gordon,
I guess you think pylon racers should use 12x6 props? And run at 9000
RPM?
Well....I'll just have to do them one better and get me some 14x10
props for my FP .40!
I can't wait to feel all that power!
<grinnin', duckin, and runnin'>
- - - -- - - - - - - --
"If I could be a bird, I think I'd be a penguin, because then I could
walk around on two feet with a lot of other guys like me."
Rob Putman
I've been doing a lot of work with the .46fx recently and have found a
10x7 or 11x6 apc prop to work just fine with this plane. However, I now
have a problem. My .46 is now 5 years old and has started quitting after
about 3-4 minutes of flight. It's getting hot and leaning out. I've
replaced all fuel line tubing, etc. I'm using Byron 10% nitro sport fuel
w/16% castor/syn blend. Took the carb apart (all looks good). Runs good
on the ground and on climbout but starts to lean after 3 minutes
regardless of flight attitude. Is mounted on a 4.8 pound Midwest Ugly
Stik.
Anyone have any ideas on what's goin' on??
Thanks,
Rob
Paul McIntosh
Rob,
Sounds like something is sucking air as the engine warms up. A couple
of sources for this is the front crank bearing/crankcase to crankshaft
seal, and the backplate seal.
The bearing may or may not be a sealed type. This seal is only to keep
dirt out, not seal air out. When an engine gets older, the seal formed
around the crankshaft and crankcase starts to go away due to normal
wear. As the engine heats up, the aluminum expands faster than the
steel causing a larger gap. Air can get in here and cause the engine to
lean without any apparent cause.
The same can occur with the backplate. Some engines depend on the metal
surfaces to do the sealing. As the engine ages, these surfaces may not
seal as well as they used to, allowing air in at inopportune times.
I have also seen carbs and carb mount ares do the same thing.
I will also make what may be an unpopular suggestion: Switch to Wings
fuel. My experience shows me that Byrons fuel gives pretty good power
but is lacking in critical lubrication. All of the engines that I ran
on Byrons fuel showed signes of excessive wear on the pistons and
crankcases. About three years ago I changed to Wings fuel ((602)
587-9140) because most of the people I flew with were using it. Since
then I noticed critical wear areas were remaing in better shape longer.
I was also able to drop from 45% nitro (Byrons) to 30-35% with the same
performance (rpm). I also save about $10 a gallon on cost!
luc...@metrowerks.com
In article <33E22B...@soundgate.com>,
wave...@soundgate.com wrote:
>
> I've been doing a lot of work with the .46fx recently and have found a
> 10x7 or 11x6 apc prop to work just fine with this plane. However, I now
> have a problem. My .46 is now 5 years old and has started quitting after
> about 3-4 minutes of flight. It's getting hot and leaning out. I've
> replaced all fuel line tubing, etc. I'm using Byron 10% nitro sport fuel
> w/16% castor/syn blend. Took the carb apart (all looks good). Runs good
> on the ground and on climbout but starts to lean after 3 minutes
> regardless of flight attitude. Is mounted on a 4.8 pound Midwest Ugly
> Stik.
>
> Anyone have any ideas on what's goin' on??
Hi Rob, Could it just be that it's approaching the end of its life? AFter
5 years, it could just be wearing out finally. Also, 16% oil isn't really
enough (at least according to O.S. it's not enough) - it should be run on
18% or more oil. Actually, I used that same fuel to break in my .61 FX,
but i'd first added 6 extra oz. of castor oil 8). Anyway, my old .61 FSR
gave me that kind of grief too after I'd finally worn it out to where it
needed rebuilding. It would only start with an electric starter due to
the low compression and it would drop in power slightly after it ran for
a minute or two..
Lucien S.
AMA560692
> Thanks,
> Rob
-------------------==== Posted via Deja News ====-----------------------
http://www.dejanews.com/ Search, Read, Post to Usenet
EthanFrme
I have been flying a Great Planes Easy Sport 40 with an OS 46FX
with an 11 X 6 Zinger prop. I can't imagine a better combination!
This combination has good speed, good vertical and it will hover
in a 5 mph breeze. I can do outside loops at about 20 feet off
the ground at the low point at 1/2 throttle (twenty + years flying
experience).
Wbpo
With a Morris Hobbies Su-do-Khoi, I am turning an APC 10.5 x 4.5
competition prop with my Tower Hobbies' Tuned Pipe equiped OS .46 FX and
can fly just about as fast up as normal flight (what ever normal is for
this plane).
W. Barrett Powell
Eastern U.S. & Canada Territory Manager
Co|Create, a Hewlett Packard Company (www.cocreate.com)
2000 Regency Parkway
Suite 600
Cary, N.C. 27511
919-460-2253
barrett...@hp.com
wb...@aol.com
Dave Tatosian
In article <33E22B...@soundgate.com>,
Rob Putman <wave...@soundgate.com> wrote:
>I've been doing a lot of work with the .46fx recently and have found a
>10x7 or 11x6 apc prop to work just fine with this plane. However, I now
>have a problem. My .46 is now 5 years old and has started quitting after
>about 3-4 minutes of flight. It's getting hot and leaning out. I've
>replaced all fuel line tubing, etc. I'm using Byron 10% nitro sport fuel
>w/16% castor/syn blend. Took the carb apart (all looks good). Runs good
>on the ground and on climbout but starts to lean after 3 minutes
>regardless of flight attitude. Is mounted on a 4.8 pound Midwest Ugly
>Stik.
>
>Anyone have any ideas on what's goin' on??
Your OS.46FX is now 5 years old? You must be residing in an alternate
universe, as the 46FX has only been around for a year!
Anyway...Presuming that you've related all the facts (and didn't leave out
some detail like moving the engine to a different aircraft, added a
pipe, etc)...
Did you check that everything is tight (like the backplate, head, and carb,
for instance)? Do you notice any air bubbles in the carb line? Has the foam
around the fuel tank (you did use foam, right?) compressed to the point of
ineffectivity? Did you replace the clunk line - and/or are you using the kind
of clunk that also acts as a filter (perhaps it's clogged). Did you try
someone else's fuel? Are you tuning the engine to get that last 50 rpm out of
it?
Cheers!
/dave
<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
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