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Old Dec 12, 2012, 06:04 PM
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North vancouver, B.C. Canada
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Quote:
Originally Posted by Waldopepperaxe View Post
Now this is something I wouldn't rebuild LOL
http://youtu.be/ACuXGTCQEmw

Hahaha

That was funny
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Old Dec 12, 2012, 07:06 PM
A trail of smoke is GOOD!
waynemia's Avatar
USA, TX, Springtown
Joined May 2008
7,226 Posts
Ad hoc formation flying is not advised! Vacuum cleaner may be required.
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Old Dec 12, 2012, 07:08 PM
A trail of smoke is GOOD!
waynemia's Avatar
USA, TX, Springtown
Joined May 2008
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New landing gear is in. Holes for the cuffs/fairings appear closer to the edge this time.
I filled them with epoxy. I am not mounting the cuffs/fairings with those screws this time.


I miss my YAK.
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Last edited by waynemia; Dec 12, 2012 at 07:17 PM.
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Old Dec 12, 2012, 09:12 PM
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North vancouver, B.C. Canada
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Anyone have ideas about propellor theories

Is there any difference in efficiency in a say 13x7 vrs. 7x13 running at same amps

Is one like the 13x7 way more efficient?

Or would 7x13 just be the same as 13x7 but just make plane faster
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Old Dec 12, 2012, 10:18 PM
Walk of Shame Season :)
Waldopepperaxe's Avatar
NY
Joined Jun 2008
4,906 Posts
Wayne good luck on the landing gear,

David no you don't want to swap prop numbers like that your talking the difference of a 7 inch prop to a 13 inch prop not a good idea for the life of the engine

Think of the prop numbers like this
13x7. 13 represents the length and swing, the 7 represents the amount of pull per revolution. Think of putting the prop in a solid liquid like a jello when the prop spins 1 full time around it would pull through the jello a total of 7 inches. So if it was a 13x8 it would travel 8 inches. So as you decrease the 1st number it would make the revolution faster so a 12x8 would cut 8" through the jello a tad faster as it doesn't take the prop as long to make the full revoluition and less load on the engine. But to drop to a 7X13 would probably cause your engine to over rev and burn it up.
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Old Dec 12, 2012, 11:05 PM
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Quote:
Originally Posted by Waldopepperaxe View Post
Wayne good luck on the landing gear,

David no you don't want to swap prop numbers like that your talking the difference of a 7 inch prop to a 13 inch prop not a good idea for the life of the engine

Think of the prop numbers like this
13x7. 13 represents the length and swing, the 7 represents the amount of pull per revolution. Think of putting the prop in a solid liquid like a jello when the prop spins 1 full time around it would pull through the jello a total of 7 inches. So if it was a 13x8 it would travel 8 inches. So as you decrease the 1st number it would make the revolution faster so a 12x8 would cut 8" through the jello a tad faster as it doesn't take the prop as long to make the full revoluition and less load on the engine. But to drop to a 7X13 would probably cause your engine to over rev and burn it up.

Thanks waldo
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Old Dec 12, 2012, 11:46 PM
Hardrock Miner
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Livingston, MT
Joined Jun 2006
752 Posts
A 13x7 prop has a PLF of 1183. A 7x13 prop has a PLF of 637. PLF is prop load factor. DxDxP= PLF. And what Waldo said.
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Old Dec 13, 2012, 06:37 AM
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Wichita, Ks
Joined Jun 2005
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I'm guessing the PLF goes up as a square of diameter because it's really proportional to prop disc surface area and pitch?

Meaning diameter has a larger effect on load than pitch does. The right prop will depend on motor rpm, wattage desired, flying speed desired, climb rate desired, "blast-off" desired, and downline/final approach "braking" effect. ... and and and ...

-Eric
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Old Dec 13, 2012, 08:27 AM
A trail of smoke is GOOD!
waynemia's Avatar
USA, TX, Springtown
Joined May 2008
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David - there is some information props here:
http://www.rcgroups.com/forums/showp...6&postcount=34

The efficiency of a prop also has to do with the shape of the prop itself. If you are interested in efficiency, I guess you are trying to convert as much of the motor power to thrust as possible.

I seem to remember that the most efficient prop is a one blade prop but I might have that wrong.

You might want to look at this article.

http://www.epi-eng.com/propeller_tec..._propeller.htm
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Old Dec 13, 2012, 09:33 AM
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winston mo
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Quote:
Originally Posted by Waldopepperaxe View Post

Rebuilding a disaster is really quite simple, add a new stick here and there a stick here a stick everywhere a stick stick
O Mc Waldo rebuilt a crash E I E I O add a stick here, add a stick there. here a stick, there a stick, every where a stick, stick E I E I O
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Old Dec 13, 2012, 09:53 AM
Walk of Shame Season :)
Waldopepperaxe's Avatar
NY
Joined Jun 2008
4,906 Posts
Nice info Guys Thanks
I never knew the load factor formula well I'm sure I've heard it mentioned here before and even saw it but of course I don't remember lol if there was only some way of retaining this information oh yeah we can look it up right here

Still learning new things every day I love this thread

or is it being reminded of things everyday LOL

Kerwin LOL

Quote:
surely you must enjoy piecing together puzzles too? I can just picture you sitting at your workbench in the basement with some tunes playing in the background......a butt smoldering in the ashtray next to you.....and you looking frantically for some debonder to free your fingers from the beer bottle you just glued your fingers to.
Snowman LOL Yup thats me and I do enjoy a good puzzle but I haven't done one in about 12 years, we started a nice 5,000 piece one on the nice big front porch overlooking the Atlantic in a 20 or so room beach house mansion we stayed at with our neighbors in Maine, but never even got the outside edges done, we worked a little bit every other night or so for a week but just relaxing and listening to the crashing of the waves while sipping on Tall frozen cocktails sort of won that battle LOL
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Old Dec 13, 2012, 11:56 AM
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United States, MI, Houghton
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Waldo, those frozen cocktails have a way of doing that!

Kerwin, I never knew you were so musical...... serenading Waldo like that!

I've been trying to forget about "the load factor".........which was defined by the droop in the diaper! As a father of seven......I've participated in more than my share!

Heavy wet snow plummeting the earth. Dead calm, but greasy. Wanting to fly my Yard Stik (which was just discontinued!!! ) or my Tiger Moth, but neither could sustain the constant bombardment from the 1/2 oz flakes.......falling from the heavens like asteroids! Did I ever tell y'all that I don't like snow......I like scotch in the winter, but not snow!
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Old Dec 13, 2012, 01:42 PM
Walk of Shame Season :)
Waldopepperaxe's Avatar
NY
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LOL Snowman, yes small foamies and snow asteroids don't go together well
Luckily so far in my life I've been able to avoid the changing of the load factor Plans for another grandchild are in the stars though I might not get so lucky this time around LOL
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Old Dec 13, 2012, 01:52 PM
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Maybe you'll be lucky and lose your sense of smell?
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Old Dec 13, 2012, 04:44 PM
A trail of smoke is GOOD!
waynemia's Avatar
USA, TX, Springtown
Joined May 2008
7,226 Posts
Quote:
Originally Posted by Waldopepperaxe View Post
LOL Snowman, yes small foamies and snow asteroids don't go together well
Luckily so far in my life I've been able to avoid the changing of the load factor Plans for another grandchild are in the stars though I might not get so lucky this time around LOL
Grand parents - especially grandfathers - are exempt from diaper duty!
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