2s is fine, but 3s is unflyable


#1

Hi,

With 1105B 6500kv motors I can fly indoors on 2s, but with 3s batteries I can’t even maintain hover. Is it a tuning thing? I kept the same configurations and only change throttle mid to make it closer to 50%

Will moving outdoors help? Do more powerful batteries just need more vertical space to maintain hover?

Thanks,

Andy


#2

i would try to move outdoors with it for a flight or two on 3s. Each battery (2s and 3s) will have a different throttle percentage to hover at on the throttle stick.

Lets say both the batteries are the same weight, the 3s would have an extra cells worth of voltage applied to the motors, which would allow the motors to spin faster with more ease so the 3s would have to “work less” on the throttle to hold it in a hover. This gives the throttle stick a lower throttle %. The 2s is missing a whole cell compared to the 3s, which is considerably weaker than the 3s so that’s why it has to work harder on the throttle to keep it in the air.

My 4s 3" hovers with barely any throttle, gotta be VERY light on the throttle stick or it’ll be out of sight lol the more cells you have on the battery, the more sensitive the throttle stick becomes.


#3

Thanks for the info. Is hover point the moment the drone leaves the ground? Or it is the throttle point where the drone doesn’t raise or fall?

I tested the batteries outdoors and there seems to be something wrong with my 3s pack setup. Now, when I try to throttle up the drone shuts down and the fc beeps (Ithink it is the arm sound). Is this called a motor/esc desync?

I also realized that I never set the motor timing on the ESCs. I assume I should switch it to high.

Although, I think I will be swapping out the motors, the rx1105 are just too loud for indoor flying.

Andy


#4

You really shouldn’t be flying 1105 on 3s indoors. Get something smaller than won’t poke holes in drywall.

Did you check the voltage of the battery when it was shutting down?

Hovering is where the quad stays in place in the air.


#5

I agree with pilsner, 1105s are huge motors lol I have an 1104 build for outdoor use only… and yes, the hover point is when the quad just chills in the air at a set altitude, not rising or falling, just hovering. For example, most of my brushed quadcopters will hover at about 50% throttle. If I then put on a set of more inefficient props on the quad then the motors struggle to grasp air, therefore my throttle % will be higher than 50% to maintain a hover.

It sounds like you may be suffering from a brown out, which is when an electrical component (FC, Rx, ESCs, Etc. ) fail to get enough electrical current due to a battery with too low of a C rating.

When you throttle up for a punch out, it sucks up MAD energy at once. If your battery doesn’t have the C current to provide all that energy at once the voltage sags too low and the FC will reboot midair due to lack of electricity.

I would try to get a battery with the highest C Rating available. 75c is ideal.

Although I am a noobie, and there could be more technical factors causing the quad to reboot midair such as desyncs, etc, but I am unfamiliar with how that all works…

Do you have OSD on your quad? If so watch your voltage as you throttle up. If it drops below 9 on a throttle punch you are more than likely on the verge of having a brown out. A 3s battery is DEAD at 9v. You should be landing at 11.1v.


#6

Hi,

The batteries are rotorx 3s 500mah HV and claims to be 80c/160c max. I have no OSD, and since it won’t take off on 3s anymore, the batteries are pretty much full.

The frame is an Armattan Bumper, the foam one, which was Why I was ok with using a larger motor imdoors, but the frame only allowed using 2 inch props. I had 20A esc as well. It’s just to heavy and loud at 2s and prolly draw too much current spinning such a short propeller.

I now plan to pair the FC/camera with 1103s on a different frame and move the 1105/esc to a larger frame.

Thanks!

Andy


#7

Also need to adjust pids for 3s