Underpowered drone - Best solution to make it fly better

Hi Everyone

My old DJI Spark crashed dramatically and I was able to use the 4 motors + props to build something new. I have already assembled a test and made the first flight at home but noticed the following: the drone seems to be underpowered because, in order to hover, the stick is at about 80% …

I think the problem behind is that I’m using a 2S lipo and I guess such motor + props are dimensioned for a 3S instead. The main problem is that the drone flights ok at the beginning with full battery but after a while, it starts to become unstable in the vertical movement.

I think the controller gives priority to the stabilization, then the vertical stability is lost because the throttle is already saturated. That’s my first guess but I’m not really sure. Now my question is: what can I do to improve this?

Considering that props are 4730 and the motor is a 1504/2100KV/12000RPM (that’s what I found here and there) and I need to stick on a 2S in order to not fall above 270/280g, ESC is a 20A if that matters … is there anything I can do to improve the situation by changing the minimum number of components?

For example, is there a way to improve the situation by simply changing the props? Or would I need more? Any idea is really appreciated

Thanks, Michael

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You need to switch to 3S power. Use a low low capacity battery to make weight and live with short flight times.

Could you explain how did you arrive at this conclusion? I would really appreciate understanding more about the considerations you have made in the background.
What if I try to cut-off some weight and maybe use different props, for example with a higher pitch. Might that help?

Are you familiar with eCalc? So lets take a look at the attached. It’s predicting roughly what you have now with a 2S battery. The key metric is Motor @ Hover, throttle linear. It says 73%, you are saying 80%. close enough. This needs to go down to 50% and there is no way you will get there with a prop change.

The next attachment is the same craft (weight, props) on 3S. What do you see for Motor @ Hover, throttle linear? Wow, those DJI guys know what they are doing…

2S

3S

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Hello Dave, thank you very much! Really appreciate your help
I will try to reconfigure it with a 3S and as second step to reduce the weight
If I can bring it down to 200 maybe the 2S will be good enough … but this is going to be almost impossible :rofl: :rofl: