Help! Mig3 - Specs for Motor and Propeller

[ajit.mahajan]

Hi all,

I am new to this forum and even in the RC Plane world. I just finished building my Mig3 in India. I had to buy parts separately. I need help in choosing the correct parts.

I tried my first flight with 1000KV Motor, 1000 mah 3S battery and 10X3.8 propeller. However looks like the thrust produced was not sufficient to make it airborne.

I have got the upgraded parts now - 1400 kv motor, 22mah 3S battery and 9x6 propeller based on the inputs from forum and other sites.

Will this work with Mig3 ? Total weight with batteries is around 627 gms.

Thanks in advance for your support.

 

[Merv]

You did not say how big the motors are. 2212, 1804?
A 1000 Kv motor that swings a 10x3.8 prop on 3S should be able to fly a 627g (22 oz) plane. Check that you have the prop on the correct way. The numbers on the prop should always face forward, towards the direction of travel. If the prop is backwards, you will only get about 25% of the thrust.

 

[ajit.mahajan]

Hi Merv....thanks for the detailed response.... My motor is 2212 type....

I also did not realize the propeller direction makes such a huge difference...let me try flight again over the weekend with the new motor (2212/1400 kv) , prop (9X6) and battery (2200 mah - 3S)..

 

[FDS]

Try rowing with the oars sideways to the intended direction, having the prop backward or the motor running the wrong way (you want CCW rotation for most props) is like that.

 

[Headbang]

2212 is a little light for the mig 3. I use a 2215 c pack motor on mine, best prop so far is a 9x6. Also on 3s. It takes a good throw to get airborne!
The mig 3 takes some skill to fly and hand launch. Hand launches can be a bit squirrelly. If on wheels and grass, you will need all the motor you can get, and a long roll out to get off the ground. This would be a perfect application for the new 2218 radial or similar.

 

[ajit.mahajan]

2212 is a little light for the mig 3. I use a 2215 c pack motor on mine, best prop so far is a 9x6. Also on 3s. It takes a good throw to get airborne!
The mig 3 takes some skill to fly and hand launch. Hand launches can be a bit squirrelly. If on wheels and grass, you will need all the motor you can get, and a long roll out to get off the ground. This would be a perfect application for the new 2218 radial or similar.

Will it make sense to run it on 1400kv (2212) motor? I have got a new battery pack too which is 3s-2200 mah.. plane look like below..

 

[Headbang]

Will it make sense to run it on 1400kv (2212) motor? I have got a new battery pack too which is 3s-2200 mah.. plane look like below..
View attachment 123020

It might be under powered. But if you do, use a regular electric prop, not a slow fly. Slow fly could fly apart at those rpm. Assuming you do not have any way to measure current of your setup, do a bench run on motor with the prop on, go full throttle for 30 to 60 secs, shut it down and see how hot the motor is. Too hot and you have too much prop. On the motor you are using I would expect a 9x4.5 would be max, or maybe an 8x6.
These are just my thoughts, maybe someone has run that exact setup before and will prove me wrong lol