Brushless system for my GWS Spitfire...

[HZM]

I am looking for a brushless system for my GWS spitfire. I would like to maintain running 2S with it.

I had 2 choice

A Himax w stock gear box

or

An AXI on direct drive

Can someone help me w shortlisting a suitable model of the motor..... advantage of one over the other.


They got Himax 4100, 4200, AXI /24 , AXI 34 etc.... just too many and I had no ideas ....

I am looking typically looking at the Himaxx 4100 bcos of the cheap price.

And one last thing, hopefully, the selected brushless system can be compatible if I go w another bird or micro heli

Thks in advance

Mike

[ammo]

himaxx will be good, since you'll be using gearbox, it'll fit right in your plane. and the choices of gears around means you can gear it or prop it to the amps draw and performance you desire on the number of cells u want.
AXI i dunno how u are going to mount but i can see it takes more work. and prop/amp is pretty much fixed. the good thing is the quiet running.

[HZM]

I too bending towards Himax .... is the 4100 suitable? How is it diff compare to 4200 .....5300 ....... just too many choice


Mike

[ammo]

4100 is 2015 size/ 300 replacement
3200, 4200 is 2025 size/ 400 replacement

go with the 2015 if ur planes are strictly on diet
else go with 2025 size for more flexibility in future ventures

if u're strictly going to only use 2s, get the highest KV wind for the size u decide.
if u are even thinking of "might" use more than 2s, get one or two steps down for the KV.
What u guys saw me use was a 2025 3200kv, running a "B" ratio on a 12x6 gws prop, on 2s. when i want to drop in a 3s, i'll change to a "C" ratio gearing on the same prop. when i want to go 4s, i'll change to a "D" ratio gearing on same prop.
It's the prop rpm that matters, not how fast the motor is running.

erm.... i lost anyone???

[HZM]

OK....a bit confuse but still not too bad......

I shortlisted Himax 2015-4100 w/Phoenix 25 .....

Now my question is... if I am on 2S and using the stock gear box and running the same prop 1080. How is it diff in term of speed / power compare to the stock motor? Am I expecting cooler batts and more power?

Sorry, those Kv seems complicated

Thks

Mike

[ammo]

higher speed, more power, slightly more or same flight times.
Battery temps slightly lower

[loyn]

Mike if not misstaken Kv is spec for the BL speed. The rpm of the motor respective to increase of 1 V. Example if a motor what given 4100 Kv, then if you are using a 7.4V battery. It will run at 4100 X 7.4 = 30340 rpm (under no load condition) On the other hand, high Kv motors are usually of lower output torque. Hence a gearbox is highly recommended for large prop. Unless you are using for high speed model with small prop. That is why those out runner motor usually need no gearbox as they are design for low rpm but high output torque.

To get the right combination of gearbox motor and prop is a form of art or trial and error if you like to call it.
1) A small prop with high gear ratio (slow speed) will go easy on you battery but will not give you much power in forward flying.

2) A small prop with low gear ratio (high speed gearbox) will give you more forward power and max speed. As it will not lost too mush relative speed as the plane start to pickup speed. On the other hand, it will have a high load on your battery.

3) A large prop with a high gear ratio will provide a lot of static thrust. (just like a heli) Hence it will good for hovering and slow 3D flying. It will go easy on your battery too if the prop is not too big.

4) A large prop with a low gear ratio (and high supply voltage, 3S)will give you a lot of forward and static power. However, it is a killer on motor and battery as the load on both element will be really high. They will not last for long in this configuration.

Hope this help Mike