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help needed to find the right electric motor

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Old 06-05-2017, 07:10 AM
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schomper42
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Default help needed to find the right electric motor

Hello,
I have been flying for about 3 years now and consider myself a beginner/intermediate flyer.
I have recently been given an old balsa rc plane with a gas engine. I want to tear out the nitro engine and put in an electric one. Here are the important specs you will want to know in order to help me pick the right motor and ESC. The plane weighs 7 1/2 pounds . This includes (2) 2200 3s lipo batteries in it. the wing is 72" long and has an area of 775 sq. in. Yes its a large wing and a heavy plane. It looks like it has a .46 engine in it with an 11" prop. I assume it flew ok with that combo. I tried using webocalc 1.7.6 and that's always a little confusing to me. I have a lot of 3s 2200 lipos and really didn't want to have to buy a new size battery like a 4s or 5s. I was thinking maybe I could take 2 of my 3s batteries and use a series connector so I would then have a 6s pack? Is this a feasible idea? Getting back to what motor I should buy. I didn't want to invest a lot of money into this old bird. I was thinking of buying this motor .
https://hobbyking.com/en_us/turnigy-...v-60-glow.html
and a

TURNIGY TRUST 70A SBEC Brushless Speed Controller

and then maybe try swinging a 12 or 13" prop
ANY suggestions or help at all would be much appreciated.
THANKS MUCH !!!!!

Bob
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Old 06-05-2017, 12:42 PM
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Type of plane and flying style make a big difference? Is the a scale slower flying plane like a Cub or a 3D aerobatic plane?
Take a read here you want to find the right "Watt" motor for the plane and flying style,, http://www.rc-airplane-world.com/watts-per-pound.html

You could run two 3s packs in series, but a 6s 2200 isn't going to give you much flight time on a 45-60 size plane,, you'd most likely want a 4000mah pack for a plane that size

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Old 06-05-2017, 03:07 PM
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That was a very helpful article . thank you.
This plane is a top wing , cub style plane . I think what I will first try is the (2) 3s 2200 packs just to see how it flys and how long it lasts. If it flys good and I like the plane , I will buy a couple 4s 4000mah packs.

thanks much !
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Old 06-05-2017, 08:39 PM
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Your hobbyking choice with a 12x12 apc or a 12x13 apc. would work fine.. the pattern props made for the old piped 61 two strokes. apc still makes them.. the turnigy is basically a copy of an eflite 60 motor. i have done several 40-60 sized glow conversions this way mainly because i didnt have the ground clearance for a bigger prop. to get the power out of an electric motor you need to load it up with the prop. the 12x12 or 12x13 will get the amps up enough to fly most 40 sized planes ok
the reality is you would probably be better to just buy a purpose built electric plane or just leave the glow alone and fly it as is. getting the battery in and out is an issue and is a pain in butt to pull the wing. each flight..

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Old 06-06-2017, 05:21 AM
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Quote:
Originally Posted by schomper42 View Post
That was a very helpful article . thank you.
This plane is a top wing , cub style plane . I think what I will first try is the (2) 3s 2200 packs just to see how it flys and how long it lasts. If it flys good and I like the plane , I will buy a couple 4s 4000mah packs.

thanks much !
A 45-46 size motor would be fine then,, something like this would run on 6S and I doubt you'd ever need more that 1000 watts for a plane like that
GForce G46 Brushless Outrunner Motor (5055-400KV) | Value Hobby

Putting a 60 size motor on is just carrying extra weight you really don't need or want with a electric plane

Good luck
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Old 06-06-2017, 06:37 AM
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Great info. I just ordered that motor with a 80A ESC.
what prop do you recommend ?

Thanks much !!!!!
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Old 06-06-2017, 01:42 PM
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What's the biggest diameter prop you can use?
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Old 06-06-2017, 03:27 PM
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13" seeing that I only fly on grass. Nicely mowed soccer fields. I probably could go to 14" if I put larger diameter wheels on it.
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Old 06-09-2017, 01:41 PM
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I ended up putting larger wheels on it. 14" prop will now fit. Any suggestions on what prop I should use on this Piper Cub?
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