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Problem with new build need help.

#1
Yesterday I finished building a hell whoop. I went out to fly it and after a 30 seconds the motors turned off. They would re arm fine and I could fly around for a bit more before the turned off again. Inspected the problem and noticed that after a while that motors are on the receiver status light flickers then turns off putting the quad into failsafe. After a second the status light turns back on and the quad arms fine. It is not like the receiver is losing signal from the transmitter because I am too far away. The problem occurs even when half a foot away but you can still arm the quad if 70 feet away. And here is another mystery the problem does not occur if motors at idle, it only occurs after 30 seconds to a minute when motors are above idle.

Any help would be great.

Components of build:
Hell Whooper frame
Racerstar 1104 7500kv motors
Racerstar 6amp Escs
Pico blx fc and pdb
Spektrum quad race receiver SPM4648
Giant Power 2s 300mah 35c lipos

image1 2.JPG
 

French

Construire Voler S'écraser Répéter
#4
That's my initial thought. I have the same AIO.

Based on your description, it seems like something is overheating/drawing too much power. How is the camera wired? To the FC, a pdb, or directly to the battery?
 

PsyBorg

Fly Angry
Mentor
#5
Why would you use 200mw on a quad that small where power limitations are already stressed? No need for anything over 25 mw on those. That is most certainly a problem and would surely send the esc's to low voltage cut off quickly.
 

TazRC

Obsession, not hobby
#6
According to specs those motors draw over 6A easily with 2030 and 2035 with throttle over about 50%. What size props are you running? I think you're pulling too many amps for the ESCs. And the JST-RCY connector is rated for only 3 amps. I run a 200mW AIO on an Inductrix and get close to 5 minutes with a 1S 220.
 
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#7
That's my initial thought. I have the same AIO.

Based on your description, it seems like something is overheating/drawing too much power. How is the camera wired? To the FC, a pdb, or directly to the battery?
5 volt regulator from the fc/pdb
 
#8
#9
I think I found the problem. Though more testing I have noticed that on a fully charged battery for the first 20 seconds of the flight you can give around 75% throttle and and the motors don't cut out. When the lips cells are around 3.7v if you give more than 50% throttle the motors do turn off. And at 3.3v per cell the throttle has to stay below 20% so you can't even take off.

This made me think it was the battery not being able to supply enough amps to power everything. So I added up all the max amps that the components consume.

motors: max amp draw = 4.1 amps x 4. = 16.4 amps

Tx03: max amp draw = 740mA = 0.74 amps

Spektrum receiver = 0.5 amps

Total amp consumption = 17.64 amps

So I need a battery that can handle at least 20 amps

When I did the calculations for my how many amps my battery can handle and I knew this was the problem

Battery: 0.3 x 35 = 10.5 amps

So I need new batteries

Options

Turnigy nano-tech 2s 300mah 45~90c
Amps: 0.3 x 45 = 13.5amps (still low)
0.3 times 90 = 27 amps

The battery's constant amps that can be drawn is to low but the burst amps it can handle is over.
I don't know if this battery will work fine because it will be under stress almost the whole flight.


The other thing that I could do is move up to 450mah and it has to be rated to only 45c. But the battery is a lot heavier.

0.45 times 45 = 20.25 amps
 
#11
Load Current is not Max and you said 7500Kv motors in 1st post.

View attachment 88744

I'm sure the battery would get really warm and probably puff before it stops supplying enough current.

Again, what size props are you running? Switch to 2030 and see if that works.
Sorry I meant racerstar 1104 7000kv motors. I am using 2035 props
So the data below is correct
Screen Shot 2017-06-05 at 07.46.18.png