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Help! Choosing the right motor, battery and esc

#1
Hey Everyone.

So I'm planning to build a slightly heavier modified version of the ft storch and would like to know how to choose my motor, esc and batteries.
The plane will be the same size as the ft storch, but possibly heavier due to the dense foam board I'm planning to use, and the modifications I intend to implement.
Can the above be worked out if the only thing I have to go on, is the weight and size of the plane, and if so, how??🤔

Any feedback would be greatly appreciated!

Have a great day!! 😎

Regards,

Daniel
 

"Corpse"

Legendary member
#2
Hey Everyone.

So I'm planning to build a slightly heavier modified version of the ft storch and would like to know how to choose my motor, esc and batteries.
The plane will be the same size as the ft storch, but possibly heavier due to the dense foam board I'm planning to use, and the modifications I intend to implement.
Can the above be worked out if the only thing I have to go on, is the weight and size of the plane, and if so, how??🤔

Any feedback would be greatly appreciated!

Have a great day!! 😎

Regards,

Daniel
I know @The Hangar loves big motors so he might be able to give you a better answer. I personally would go with something like this, Cheap, Big, and so far has good reviews.
https://www.amazon.com/dp/B077HLPP4N/?tag=lstir-20
 

The Hangar

Fly harder!
Mentor
#5
Hey Everyone.

So I'm planning to build a slightly heavier modified version of the ft storch and would like to know how to choose my motor, esc and batteries.
The plane will be the same size as the ft storch, but possibly heavier due to the dense foam board I'm planning to use, and the modifications I intend to implement.
Can the above be worked out if the only thing I have to go on, is the weight and size of the plane, and if so, how??🤔

Any feedback would be greatly appreciated!

Have a great day!! 😎

Regards,

Daniel
Yes - you’ll be totally fine. Ft planes are much lighter in general than pre-built planes you can buy from eflite or other companies. This motor will be plenty:
http://www.valuehobby.com/power-systems/brushless-motors/outrunner-airplane/gforce-g32-800kv.html
You could probably get away with their 3536 1100kv as well.
 

TheFlyingBrit

Legendary member
#7
Dé jà vu
Build it first and measure the weight difference between a FT version and yours its probably not too dissimilar other than a heavier tail. Therefore the recommended FT motor may be suitable, you just need to balance it out at the CG.
I use a heavier denser board all the time.
 

TheFlyingBrit

Legendary member
#8
But if you want a good motor with excellent performance get this.
1608057917985.png
Sunnysky x2216 1250kv
30 amp ESC should do with 3amp BEC
9x5 or 10x4.7 prop and a 3s battery
;)(y)
 

TheFlyingBrit

Legendary member
#10
Have you checked the power output on this motor its 320 watts ? Its small but beefy for its size.
Ive flown a 3ch 36" balsa trainer with one of those motors, also my 4ft wingspan Balsa powered glider and my Simple cub. I am sure it can handle a std size Storch ?
It will produce 1350 g of trust with a 3s and 10x4.7 prop, Watts 320.
Might have got the amps wrong there closer to 29A, so better with a 40amp ESC
(I used the smaller 9x5 prop for my models, so got away with lower 30amp ESC, it had a lower 200 watt output).
 
Last edited:

TheFlyingBrit

Legendary member
#11
Need to determine how heavy the plane is before you start specing motors tbh.
He stated same size model just slightly modified with denser foam board, so its heavier, but by how much 20g or 1kg ?
The Sunny sky will take a 4s too, so you can get even more benefit (y)
 

The Hangar

Fly harder!
Mentor
#12
Have you checked the power output on this motor its 320 watts ? Its small but beefy for its size.
Ive flown a 3ch 36" balsa trainer with one of those motors, also my 4ft wingspan Balsa powered glider and my Simple cub. I am sure it can handle a std size Storch ?
It will produce 1350 g of trust with a 3s and 10x4.7 prop, Watts 320.
Might have got the amps wrong there closer to 29A, so better with a 40amp ESC
(I used the smaller 9x5 prop for my models, so got away with lower 30amp ESC, it had a lower 200 watt output).
The motor I linked puts out 720 watts, or 6 pounds of thrust. Like I said, probably a bit overkill but it’ll definitely fly a storch that’s overweight. The 3536 I mentioned in my previous post puts out 420 watts.
http://www.valuehobby.com/g10-lc3536-1100kv-outrunner.html
 

TheFlyingBrit

Legendary member
#13
Great to have an over spec motor it gives you additional power and speed when you need it yet plenty of control around the half throttle position.
However, there are down sides particularly if you over over spec: Extra nose weight and reduced space to fit the motor, larger more costly ESC needed and a bigger battery (extremely costly).
Flight characteristics: Torque roll on take off, that can be a knee knocker. Potential high speed/thrust for a plane that was not designed for that type of flight, it will increase load on the airframe possibly leading to fatigue and failure.

I fly a WOT trainer which is balsa and weighs in at 2kg with a 4s 5000mAh battery. The motor I use will allow it to cruise around at half throttle of fly vertical at full throttle. It uses an Emax GT3520 /5 925kv, max thrust is 3100g (8lbs) and will fly a model upto 3kg weight. Power output is in excess of 700 watts.
So its not that dissimilar in spec to your motor, which would be scary in a foamboard Storch seriously ! Unless it had paving slabs to weight it down ?
As I have said before, you spec your motor based on your planes: weight/wing loading and its primary use ie glider, trainer, scale, sport aerobatic or 3D highly aerobatic.
First build the plane then weigh it, then decide what it going to be used for ie trainer, scale or basic aerobatic and choose a motor acordingly.

The Sunnysky motor I suggested will out perform a lot of larger motors on the market and will easily fly a 1kg plane balsa or foamboard. I was assuming his build would be around the 1kg mark fully loaded. It would allow the plane to perform basic rolls, loops etc or just plod around the sky like a scale plane.
 

TheFlyingBrit

Legendary member
#14
My first balsa IC to electric conversion, using the Sunny sky x2216 motor. The model was called The Elf (reminded by another post) and was a 3ch trainer, the cowel was another modified coke bottle (diet).
0_20190329_144309.jpg 1_20190329_144258.jpg 2_20190329_144243.jpg 4_20190329_144150.jpg 5_20190329_144133.jpg
Apologies for the image quality.
This plane quite flew fast considering and ran of a 3s 2200mAh lipo
 

"Corpse"

Legendary member
#15
#18
Hi all!

Thank you everyone for the awesome response.

Here is some more info. So I guess I'm asking, given the original weight and size of the FT Storch, combined with the "modifications" below, how much heavier do you think the storch would be, and taking that into consideration, how do I decide on what hardware to use?

So the plane will be the same size as the FT Storch. I will be using 5mm FOAM X (not forex) foam board which is more dense and the paper is almost like thin cardboard but thicker than paper (google it). I will be doubling up only the rudder and elevator, 10mm thick instead of the std 5mm. The wing will be built to look like a plane that is bought in a shop, ie, completely closed with the flaps and ailerons fully built in a triangle shape looking from the side, whereas the normal ft storch is just the top part of the wing score cut to work as ailerons.
I hope this is making sense.
The landing gear will be exactly the same as the ft storch, except the wire will sit inside carbon fiber rods for sturdiness and to look nice.
I will still be using the std power pod design and the rest of the plan is as far as the fuselage goes remains the same taking into account the thickness of the rudder and elevator.
 

The Hangar

Fly harder!
Mentor
#19
Hi all!

Thank you everyone for the awesome response.

Here is some more info. So I guess I'm asking, given the original weight and size of the FT Storch, combined with the "modifications" below, how much heavier do you think the storch would be, and taking that into consideration, how do I decide on what hardware to use?

So the plane will be the same size as the FT Storch. I will be using 5mm FOAM X (not forex) foam board which is more dense and the paper is almost like thin cardboard but thicker than paper (google it). I will be doubling up only the rudder and elevator, 10mm thick instead of the std 5mm. The wing will be built to look like a plane that is bought in a shop, ie, completely closed with the flaps and ailerons fully built in a triangle shape looking from the side, whereas the normal ft storch is just the top part of the wing score cut to work as ailerons.
I hope this is making sense.
The landing gear will be exactly the same as the ft storch, except the wire will sit inside carbon fiber rods for sturdiness and to look nice.
I will still be using the std power pod design and the rest of the plan is as far as the fuselage goes remains the same taking into account the thickness of the rudder and elevator.
Great mod ideas - I’m eager to see how they turn out. One big benefit to the first motor that I linked is that it’s fairly large and will give you nose weight to help counteract the tail-heavy nature of building with heavier foam (especially with doubling up the control surfaces.)
 
#20
Great mod ideas - I’m eager to see how they turn out. One big benefit to the first motor that I linked is that it’s fairly large and will give you nose weight to help counteract the tail-heavy nature of building with heavier foam (especially with doubling up the control surfaces.)
I think the next step for me would be to get the plane built so that I can determine the weight, and then return to this forum to see which of the suggestions might suit the plane the best.😎