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Old Feb 17, 2013, 11:18 AM
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BlinkguY's Avatar
United States, NJ, Newark
Joined Nov 2005
2,061 Posts
Quote:
Originally Posted by BattleDude View Post
Hi Guys,
Well... just had to spend some money, it was burning a hole in my pocket!

Have a P47, retracts, flap servos, extra battery, ordered up! Can't wait. I think this plane is going to suit me well. It appears to fly so stable, and take-offs and landings look like they are easier than alot of planes, in the vids I have watched.

Get ready for many noob questions fellas!

First one: do real airplanes have the motor/prop offset to compensate for the P-factor?

Thanks!
Kyle



Fleet:
PZ UM P-51 Mustang
PZ UM Spitfire Mk IX
PZ BF109G
PZ Spitfire Mk IX
Dynam PBY Catalina
Blade 120SR
Blade mCX2

well, it is true.. on single engines it tends to go to the left... like the cessna 150. and the two engines aircraft is worst i know somebody will come with the better answer (more technical) and since the rc planes are really light and smaller, the effect might be a little bit more noticeable
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Old Feb 17, 2013, 11:28 AM
Right Rudder
PittSpecial's Avatar
USA, FL, Orlando
Joined Nov 2010
9,731 Posts
Quote:
Originally Posted by BattleDude View Post
Hi Guys,
Well... just had to spend some money, it was burning a hole in my pocket!

Have a P47, retracts, flap servos, extra battery, ordered up! Can't wait. I think this plane is going to suit me well. It appears to fly so stable, and take-offs and landings look like they are easier than alot of planes, in the vids I have watched.

Get ready for many noob questions fellas!

First one: do real airplanes have the motor/prop offset to compensate for the P-factor?

Thanks!
Kyle
Kyle,

Beside the my Posted reply to you from last page

This one is super interesting...as you can see what it takes to off-set the P-Factor in a Full Size Aircraft such as the Cessna.

As takeoff airspeed is approached, gentle back pressure on the control wheel raises the elevator which causes the airplane's nose to pitch upward slightly. This lifts the nose wheel off the runway
(see fig. below).



Once the nose wheel is off the runway, the more right rudder will probably have to be applied to counteract the left-turning tendency which is greater once the aircraft leaves the ground. As the airplane lifts clear of the runway, the pilot varies the pressure on the control wheel. First, pressure is relaxed slightly to gain airspeed while still in ground effect (additional lift provided by compression of air between the airplane's wings and the ground). As airspeed increases to the best rate-of-climb airspeed, back pressure on the control wheel is adjusted to maintain that airspeed until the first desired altitude is reached.

Again, more reading at:
http://www.pilotfriend.com/training/..._off_climb.htm
.
.
.
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Old Feb 17, 2013, 12:35 PM
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Diesel6401's Avatar
United States, NC, Charlotte
Joined Sep 2009
3,022 Posts
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Originally Posted by walter3rd View Post
WHAT BATTERIES ARE YOU GOING TO USE? what prop? post pics when finished..
Ill be going 3s.
E-Flite 3s 2200mah 30C
Sky Lipo 3s 2200mah 40C
Turnigy 3s 2200mah 40C
Pulse 3s 2250mah 45C (my favorite)

2200 is enough, if I'm easy on the throttle I should get decent flight time. if not I have some 3300mah size packs I don't want to go that route though.

I plane on using a E-Flite 11.75x7 though. I broke my APC 12x8 which I wanted to use. Ill get another. I have a APC 10x7 that I bored the hole out of, but I think will be small.
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Old Feb 17, 2013, 02:12 PM
I just want to go fly!
walter3rd's Avatar
United States, MD, Towson
Joined Aug 2012
2,563 Posts
officially done guessing! :)

so i finally got my watts up meter! thank goodness. i tested the 4 blade GWS as well as the EXTRA 300 prop with fresh 2500-2600 batteries and they were almost identical at full throttle. about 33.5 A. these figures didnt last long as the batteries started to drain but i was very happy to not see a big figure with the 4 blade. i did run a 11 diameter apc just to see what it would draw and it was around 44 a. that was just a quick comparison. speed aside.. it would seem the GWS and EXTRA 300 prop are well within safe limits. is it true that in the air the amp draw is actually a bit lower??? sounds like they are both safe as i have the external cc bec 10 amp installed too. thoughts? the 4 blade is MUCH prettier as well. where the hell are those darn hobby lobby 4 bladers! those are REALLY SEXY!!!!!!!popcorn: just glad im not in the dark any more.. walt.
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Old Feb 17, 2013, 02:18 PM
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JDMJim's Avatar
United States, IL, Joliet
Joined Jul 2011
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I would be giddy if a had a 4 blade on mine....prolly too giddy to stand up
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Old Feb 17, 2013, 02:23 PM
Right Rudder
PittSpecial's Avatar
USA, FL, Orlando
Joined Nov 2010
9,731 Posts
Quote:
Originally Posted by walter3rd View Post
s. is it true that in the air the amp draw is actually a bit lower???
walt.
Hi Walt,

It is the same principal as a RC Car.....once it gets started the AMPs levels off.

With an Airplane once the model is in the air and flying the propeller is now in a steady state condition such that the AMP draw is several AMPs below....how much??? To know exactly you need to invest in onboard Measuring devices....not really worth it.
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Old Feb 17, 2013, 02:29 PM
I just want to go fly!
walter3rd's Avatar
United States, MD, Towson
Joined Aug 2012
2,563 Posts
jdmjim... the jug is extra sexy with a 4 blade on there! throw on one and see if you like it. watt test first of coarse! .. never know till you try?
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Old Feb 17, 2013, 02:30 PM
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Diesel6401's Avatar
United States, NC, Charlotte
Joined Sep 2009
3,022 Posts
Its funny that in rc planes 1/2 throttle or anything less than full is good to lower amp draw, in boats however its 100% opposite. Running less than full can blow your esc, full or bust. Nature of the beast!
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Old Feb 17, 2013, 02:46 PM
I just want to go fly!
walter3rd's Avatar
United States, MD, Towson
Joined Aug 2012
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thats interesting.. is it the surface drag of the water? once it pops up on plane i guess theres less touching the water?
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Old Feb 17, 2013, 02:57 PM
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Diesel6401's Avatar
United States, NC, Charlotte
Joined Sep 2009
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Quote:
Originally Posted by walter3rd View Post
thats interesting.. is it the surface drag of the water? once it pops up on plane i guess theres less touching the water?
Yup! Less drag and when it's porpoising to get on plane high amp spikes occue. Once on plane and full throttle higher speed means more water flow for cooling the electronics

anything less then full is kinda hard on escs. They're switches either on/off. Less than full (on) means they're cycling rapidly to meet your throttle request. Planes are typically very mild in amp draw. Sub 75 mostly even sub 40 for most bnf/rtf/pnp setups, so its not issue at all running less than full. A typically rtr boat averages 60amps. I have setups 4s, 5s, 6s setups pulling 150-200+ amps in boats..... just thought its cool how different things act depending on application. Hopefully not too far off topic.
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Old Feb 17, 2013, 03:33 PM
I just want to go fly!
walter3rd's Avatar
United States, MD, Towson
Joined Aug 2012
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doesnt bother me. i like to learn how these electronics work. im new to the game.
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Last edited by walter3rd; Feb 17, 2013 at 03:39 PM.
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Old Feb 17, 2013, 03:56 PM
I can fix it.
nageotte's Avatar
Cochranton, Pa.
Joined Nov 2005
1,402 Posts
Quote:
Originally Posted by BattleDude View Post
Hi Guys,
Well... just had to spend some money, it was burning a hole in my pocket!

Have a P47, retracts, flap servos, extra battery, ordered up! Can't wait. I think this plane is going to suit me well. It appears to fly so stable, and take-offs and landings look like they are easier than alot of planes, in the vids I have watched.

Get ready for many noob questions fellas!

First one: do real airplanes have the motor/prop offset to compensate for the P-factor?

Thanks!
Kyle

Fleet:
PZ UM P-51 Mustang
PZ UM Spitfire Mk IX
PZ BF109G
PZ Spitfire Mk IX
Dynam PBY Catalina
Blade 120SR
Blade mCX2
Some of the lighter aircraft have the dorsel fin offset. My Aeronca had the leading edge of the fins offset about an inch and a half.

Heavier planes have rudder trim in the cockpit. Part of the preflight is to crank in some right rudder trim. And the thrust line is indeed angled down.
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Old Feb 17, 2013, 05:33 PM
We all fly West in the end
bmrmiller's Avatar
United States, TN, Powell
Joined Dec 2011
58 Posts
Well, I just returned from the maiden of my PZ P-47 I built this week. I used the G25 870kv, motor with a MAS 10x8 prop and a 65 amp Hobbywing ESC. Temp was 38 with a 8 mph westerly wind. I ran 8 batteries through her.She handled very nicely.REALLY like having flaps.... Although not a speed demon like my PZ Spitty, she is still one nice bird to fly. Handles very well, did Immelmanns, Cuban 8's, barrel rolls with ease. She really does look good in the air. Two thumbs up :-)
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Old Feb 17, 2013, 05:46 PM
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United States, NC, Charlotte
Joined Sep 2009
3,022 Posts
I ended trying a APC 11x8.5. Bench tested at 415 Watts after 3 seconds runup. She's finished now to maiden. The wings I have are new, the body I got used so she's definitely pieced together. Depending how much I like her ill buy another airfrane and do a different setup maybe with more blades and redtail scheme. I don't like the static look of the 2 blade.
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Old Feb 17, 2013, 07:27 PM
I just want to go fly!
walter3rd's Avatar
United States, MD, Towson
Joined Aug 2012
2,563 Posts
i hear ya! static 2 blade is lame.. you got to go 4 blade at least for static display. with this weather im mostly static these days. boring... maybe a maiden this sunday.. high 40-50 degrees and 6 mph wind. fingers crossed. i dont want to wait till spring.
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