J-3 Cub build
 

Hello all. Dan here. I have been flying for 30yrs and have had a few electric rtf's
but this is my first kit built glow conversion.
It's a Great Planes 20. J-3 Cub with a 61" wing.
First, I built the wing with a servo for each aileron (strip ailerons) so I could set
differential. Now, the question.....Do you think flaperons would be of any use on a plane like this ?
second, I am a bit over powered with a GH2820-05 spinning a 11-6 prop, a GH 50a. esc and 7a. ubec. I would like to use a 3s lipo. Any idea what size I should get ? I would like to get about a 10min flight and figure this motor will only need half throttle to cruise and should go vertical at 3/4! A least that's what my math said.......amps :censor: watts = kw's - volts...???... I like electric but can't get the hang of figuring the math out.

Hi and Welcome to Wattfliers, The Cub has a lot of drag to it, so IMHO i dont think you need Flaperons,

here is some info that will help.
http://www.rccanada.ca/rccforum/showthread.php?t=131349

IMHO a 4000mah 3cell 25 to 50C Lipo will work well, it wont be to heavy, and it will give you some good flight time
http://www.hobbyking.com/hobbyking/s...Lipo_Pack.html

the Grayson 3536 1000kv motor is a nice motor, it should work very well, always over power your E Power planes :) use a Castle Creation 10 amp UBEC, because the Grayson ESC does not have a built in BEC to it.
http://www.headsuprc.com/servlet/the...-CC-BEC/Detail

http://www.wattflyer.com/forums/show...t=ubec+chellie



Motor Stats:
Li-Po Battery: 3 / 5 cells
RPM per volt: 1,000
Max efficiency: 80%
Max efficiency current: 18 - 30A (>75%)
No Load Current / 10V: 2.1A
Max Current: 40A / 60 sec
Dimension: 35 x 36mm
Shaft 4mm
Weight: 132g / 4.6oz
Max Watts: 550W
Continuous Watts: 480W
Recommend ESC: Grayson Hobby 50Amp WITHOUT BEC
Recommend Prop Range: 11 x 6 on 3-cells (11.1v) & 10 x 7 on 4 cell (14.8v)
Recommended Model Weight: 35oz - 88oz / (2.18lbs - 5.5lbs)

I have a e-flight cub and a goldberg 76 inch wingspan cub ,a hanger-9 -80 inch cub and a 1/3 scale sig cub and dont use flaperons on any of them . I also fly all them off of water .:D joe

Thank you for the info!
4000mah is right where I was looking. In fact, I picked up two of the 2200 packs they had on sale and figured I would run them parallel for 4400mah.
Joe, I take it you like Cubs??!!
I didn't think I would need flaperons but now that I have a radio that allows me to do it
I just thought it might be something to play with. I just didn't want to flip the switch and go into a death spiral !

Yea i like cubs ,for ex-mas my girlfriend and son buoght me a funcub so it will be the first one with flaps i have ever owned . I think flaperons and crow is great for funfly planes and some 3-d stuff but not needed on a cub. Iam a builder so it would have been easy for me to cut in flaps on all my cubs but again its extra weight and more toggles to flip while flying and cubs are meant to be relaxing flying . :D When i was flying pattern i had a 14 channel radio with all the good stuff that i could program a push button to do a snap roll , i enjoy doing my own snap rolls so the function was never used. ;) joe

What power system are you using on your Goldberg Cub? I have one that I need to build, I haven't decided on a power system yet.

Will

Since i fly nitro ,gas, and electrict i run a electrict e-flight 25 on my e-flight cub and my goldberg cub has a 61 OS four cycle, my hanger -9 cub has a OS 46 2 cycle and my sig 1/3 scale cub has a G-38 gas motor on it. joe

Joe, That's quite the range of power! This is my 3rd Goldberg Cub, all of the others were nitro powered and they flew great. This is one is going to be electric though.

Will

This is the power system I bought for our 76"ish cub that had a .40 4 stroke on it. Will be powering with 5000mah 4s o

NTM Prop Drive Series 42-38 750kv / 785w (USA warehouse)


NTM Prop Drive 42 Series Accessory Pack (USA Warehouse)


TURNIGY TRUST 70A SBEC Brushless Speed Controller (USA Warehouse)

Just be carefull of the bigger e- motors and put one of these in for safety http://buyradiocontrolledplanes.com/...products-6970/ joe

Flaperons, "crow", etc. are used effectively on sailplanes but they're not necessary or recommended for powered propeller models. A lightly wing loaded Cub or similar does not need flaps for takeoffs or landings. I have flaps on my foamy PZ Stinson Reliant and enjoy using them for short take-offs, very slow fly-byes, touch and goes and short landings but they can get you into trouble if not used properly and are not necessary for normal flying.

I agree with everyone here that flaperons are not necessary but they are alot of fun to play with. It can add another dimension to your flying and is just another way you can expand and have fun.

Jim