do i need to change my motors and esc?

Started by ananya, May 30, 2020, 09:01:20 AM

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ananya

Hey, I am a newbie into the hobby. I have a 250mm frame and on friends say got 1400kv motors to power it along with 30A ESC, the FC used is MAMBA F722S. now I am confused as to what battery to get... I am thinking of 3s 2200 or 2600mah.


Is the battery capacity I am aiming too much heavy or too powerful ? will my drone take flight or do I need to change the motors to 1800 or 2200kv motors? Should I continue with the ESC or invest and get the ESC-PDB stack of mamba for 4k?

I am too new so any help would be much appreciated

Mandy

250mm means 5-6inch props, for a 1400kv and 6inch you will require 6s batteries. 3s or 4s will not work so well. if you want to run 3s-4s you will require something 1900kv for 6inch props and 2300-2600kv for 5inch. 3s will not work efficiently with a 1400kv motor.

Nirup MS

for a 250mm frame required props are 5-6inch....but the 1400kv uses 8inch i guess..but to run 1400 with 5 or 6 inch u need higher cell lipo..so better go for  a 2200-2500kv motors and a 3-4s 20a or 30a esc...with this setup u will be able to run on 3s or 4s lipo..

K K Iyer

@ananya,
Welcome to the forum.

Based on the information provided in the first post, here are some guesses/ estimates that may assist you:
1. You didn't mention the make/ specifications of the motors. I guess they are probably generic 2212 motors (of 1400kv). Their weight is probably around 60gms each.
2. Weight of your 30amp Escs is probably around 35gms (Incidentally 20amp Escs may have been more than enough)
3. Weight of motors+Escs+props about 4x105 or say 420gms
4. Weight of frame, FC, PDB, Rx etc say 80-100gms
5. Total say 500-520gms without battery (My ST360 is 630gms without battery)
6. Let us assume we use a 3s 1500mah lipo (125gms)
7. Ready to fly weight say 600-650gms

I ran a check using an old iPower 2212 1400kv motor.
With a 6x4 prop, on about half throttle, the thrust was 150gms, using only 4amps/50watts.
Four of these would be enough to hover a 600gm quad.
At 16amps, the 1500mah lipo would give about 4-5 minutes hover time before recharging.
(330gms thrust at 9.5amps/110watts at full throttle, from each motor)

Now assume we use a 3s 3000mah lipo (250gms)
So ready to fly weight say 750-800gms.
With a 7x4 prop, on about half throttle, the thrust was 220gms, using only 4.8amps/60watts.
Four of these would be enough to hover a 800gm quad.
At 20amps, the 3000 lipo would give about 8-10 minutes hover time before recharging.
(575gms thrust at 16amps/190watts at full throttle, from each motor. This will be about 3:1 thrust to weight. Doubt if you'll need it!)

Remember that your motors are probably rated only for 3s, and will burn on 4s or more.

Hope this helps.
Best wishes.