Dec 12, 2012, 07:04 PM
Suspended Account
Joined Apr 2008
19,406 Posts
Quote:
 Originally Posted by Waldopepperaxe Now this is something I wouldn't rebuild LOL http://youtu.be/ACuXGTCQEmw

Hahaha

That was funny
 Dec 12, 2012, 08:06 PM A trail of smoke is GOOD! USA, TX, Springtown Joined May 2008 7,234 Posts Ad hoc formation flying is not advised! Vacuum cleaner may be required.
 Dec 12, 2012, 08:08 PM A trail of smoke is GOOD! USA, TX, Springtown Joined May 2008 7,234 Posts 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. Last edited by waynemia; Dec 12, 2012 at 08:17 PM.
 Dec 12, 2012, 10:12 PM Suspended Account North vancouver, B.C. Canada Joined Apr 2008 19,406 Posts 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
 Dec 12, 2012, 11:18 PM Walk of Shame Season :) NY Joined Jun 2008 5,565 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.
Dec 13, 2012, 12:05 AM
Suspended Account
Joined Apr 2008
19,406 Posts
Quote:
 Originally Posted by Waldopepperaxe 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
 Dec 13, 2012, 12:46 AM Hardrock Miner Livingston, MT Joined Jun 2006 759 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.
 Dec 13, 2012, 07:37 AM 3.14159265358979323846264 Wichita, Ks Joined Jun 2005 1,986 Posts 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
 Dec 13, 2012, 09:27 AM A trail of smoke is GOOD! USA, TX, Springtown Joined May 2008 7,234 Posts 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
Dec 13, 2012, 10:33 AM
Registered User
winston mo
Joined Oct 2006
8,524 Posts
Quote:
 Originally Posted by Waldopepperaxe 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
Dec 13, 2012, 10:53 AM
Walk of Shame Season :)
NY
Joined Jun 2008
5,565 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
 Dec 13, 2012, 12:56 PM Registered User United States, MI, Houghton Joined Jan 2005 6,758 Posts 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!
 Dec 13, 2012, 02:42 PM Walk of Shame Season :) NY Joined Jun 2008 5,565 Posts 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
 Dec 13, 2012, 02:52 PM Registered User United States, MI, Houghton Joined Jan 2005 6,758 Posts Maybe you'll be lucky and lose your sense of smell?
Dec 13, 2012, 05:44 PM
A trail of smoke is GOOD!
USA, TX, Springtown
Joined May 2008
7,234 Posts
Quote:
 Originally Posted by Waldopepperaxe 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!