Need a reliable 60A+ fixed wing ESC recommendation for 80" scale Northrop N9M re-build (pic of plane as I got it included)

[Aviphysics]

I need a good 60A+ Fixed Wing ESC recommendation. This is for the pictured Northrup N9M that I am re-building. It seems to have been built in the 80's from Bill Young's 1983 plans.

• The motors will be a pair of X2212 V3 1250kV power by 4S and spinning either 8040 or 8060 props.
• The plane without motors and batteries is 1400g. I am thinking the final flight weight will be about 1800g.

I was thinking of using a pair of APD 80F3[x] V2 and dedicated BEC, as my general experience with integrated BEC has been awful.
I am wondering what other people would recommend.

 

[jure]

here you may find some data for this motor operating at 4S
SUNNYSKY-X2212-1250KV-III-V3-Brushless-Motor
Note that about 500W total , for a 5 lb AUW plane may be "just" fine.

SUNNYSKY X2212 1250KV III (V3) Brushless Motor
Product Details
Specifications X2212
Stator Diameter 22mm
Stator Thickness 12mm
No.of Stator Slots 12
No.of Rotor Poles 14
Motor Kv 1250
NO-Load Current(A/10V) 0.6A
Motor Resistance 54mΩ
Max Continuous Current 37A/30s
Max Continuous Power 518W
Weight 59g
Rotor Diameter 27.5mm
Body Length 30mm
Max Lipo Cell 3-4S
ESC 20-30A
Recommend Prop(inch) APC8038 APC1047 APC1038 APC9047 APC9045
Application recommendation:
Multicopter single rotor load 400g 3-4S 10381047）
Multicopter single rotor load 500g（4S 8038804380459047)
3D airplane flight weight 550g (3S 1047)
TRAINER flight weight 750g 3S 1047

based on this information, I would say that a 60A ESC for each motor would be an overkill , but safe nonetheless.
What I would recommend in a twin, is to use two batteries, one for each motor/ESC.
A Switch Mode BEC would be appropriate for your case ( ie . : 4S operation).

 

[Aviphysics]

You are looking at the specs for the 950kV version. I got the 1250kV version. With an 8060 prop on 4S at mid charge, it should pull about 35A per a motor to produce 1.35kg/each at full throttle, according to the sheets from SunnySky. Of course, at full charge it could pull more current. That is why I am looking at 60A ESC.

Considering the original brushed motors this plane came with, I expect it should be plenty of thrust.

SunnySky X Series V3 X2212 V3 Long Shaft Brushless Motors

SunnySky X Series V3 X2212 V3 Long Shaft Brushless Motors

sunnyskyusa.com

here you may find some data for this motor operating at 4S
SUNNYSKY-X2212-1250KV-III-V3-Brushless-Motor
Note that about 500W total , for a 5 lb AUW plane may be "just" fine.



based on this information, I would say that a 60A ESC for each motor would be an overkill , but safe nonetheless.
What I would recommend in a twin, is to use two batteries, one for each motor/ESC.
A Switch Mode BEC would be appropriate for your case ( ie . : 4S operation).

View attachment 16279

View attachment 16280

 

[jure]

you could buy these ESCs at your friendly store

40A ESC
UBEC 6A

another topic.
Does the model have landing gear ? How will it take off ? Hand launch ?

 

[Aviphysics]

you could buy these ESCs at your friendly store

40A ESC
UBEC 6A

another topic.
Does the model have landing gear ? How will it take off ? Hand launch ?

It has retracts

40A doesn't have much margin. Remember, the motor specs are giving current consumption at 3.7V per a cell. It's going to be a bit higher at 4.2V per a cell.

Maybe 40A would be just enough, but I would rather spend the extra for a little more margin.

 

[jure]

You are looking at the specs for the 950kV version. I got the 1250kV version.

correct, the page I found was listing the incorrect data for Kv = 1250 RPM/V , 4S operation , that I selected.
from your link , I took the 4S data pasted below:

More power output then !
about 500W , 35 A , per motor, at full throttle.
This will be very good !

OTOH ,
515.04 W / 59 g = 8.79 W/g sounds a bit over-optimistic , i.e. "fantastic" (grin).

 

[Aviphysics]

correct, the page I found was listing the incorrect data for Kv = 1250 RPM/V , 4S operation , that I selected.
from your link , I took the 4S data pasted below:

View attachment 16315

More power output then !
about 500W , 35 A , per motor, at full throttle.
This will be very good !

OTOH ,
515.04 W / 59 g = 8.79 W/g sounds a bit over-optimistic , i.e. "fantastic" (grin).

So far I have got pretty on spec results from Sunnysky motors.

I think the extra W/g comes from using a higher temperature magnet wire coating. I got a little into motor rewinding and discovered that there is a pretty big difference between the available coatings, and not everyone uses the highest temperature tolerance coating.

 

[jure]

me too, I did a lot of rewinding BLDC motors.
It is a technology development issue: better magnets, better and thinner stator lamination , better window copper filling.
all of them result in lower losses , which allow higher power density.