Problems plaguing my first build

N

Nightham

Member
I have posted these questions on multiple forums before and so far have yet to come across a straight answer as to how to go about fixing the problem I've been having with my first build.

This quadcopter has been earthbound for about 4 years now, and admittedly the first mistakes were due to a bad combination of parts that were too ambitious.

6S 5000maH turnigy Li-po
10x4.5 props
800kV turnigy motors
CC3D flight Controller
5 channel Tx/Rx
some generic but fairly sturdy frame
30A non-BEC ESC's
1500MaH Ni-Cd (for powering flight controller due to non-BEC esc's)
The quad is a bit on the heavier side, between 0.8 and 1.5kg's


Our initial problem? Far too much thrust, I was expecting a far heavier body and counted on being able to dial back the thrust enough. But the flight controller (LibrePilot) was not at all intuitive with changing throttle and power supplies to the motors. Many have suggested either buying a better flight controller or flashing new firmware onto it and using a different program, but the CC3D board was giving me all sort of problems with flashing new firmware and no guides I could find were that helpful at fixing that problem.

Eventually, I decided to lower my batter down to a 4S 5000MaH li-po instead, and should the thrust then be too low, I could add large 12" props to the frame to compensate.

The new setup is as follows

4S 5000maH Li-po
12x4 props / 6x3 props / 10x4.5 (there is an assortment for testing)
800kV turnigy motors
CC3D flight Controller
5 channel Tx/Rx
some generic but fairly sturdy frame
30A non-BEC ESC's
1500MaH Ni-Cd (for powering flight controller due to non-BEC esc's)
The quad is still a bit on the heavier side, between 0.8 and 1.5kg's

Here's were my most recent issues come into play

It seemed that even though I changed the battery from a 22.2v li-po (6S) down to a 14.6v li-po (4S), the thrust was still way to high to idle the propellers at minimum throttle. I've tried everything I can do on LibrePilot to remedy this issue, and I know the motors can have a lower RPM since doing the test where you find the lowest voltage at which the motor begins to turn. I just can't seem to find a way to make the lowest "tick" of throttle on the controller be the lowest amount of power sent to the motors.

(and as long as I'm listing problems with the current system, the throttle on it has been working really weird as well, where it goes up to about 10% throttle, holds at 50% until the stick reaches 50%, then ramps up more from there. I have tried adjusting the throttle curve but that seems to be of no use.)

I feel like this problem must be bigger as well, considering I saw almost no change in performance between the 6S li-po and the 4S li-po, but I'm at a loss as to why nearly cutting the voltage in half did nothing to affect performance.

I understand some of the hardware I'm using is old, I know there are better parts ion the market today, but I'm not going to sink any more money into this quadcopter unless there is a hopeful solution at the end of the shopping list. On batteries alone, I have spent 100$ just trying to troubleshoot and I have yet to make any progress since day one. If you suggest buying new hardware, please include a link and an explanation as to how that will help get things airborne.
 
In the receiver settings, what is minimum throttle? =1000, mid point =1500,
max throttle =2000.
I take it you will only be arming by stick, only having a 5 channel Tx. 4 for sticks then the 5th for modes on SWC the 3 position switch. You ain't building an acro quad so you will have to apply angle mode at least. You have not listed your
Power distribution board. Get one with a 12v + 5v out, saves the extra battery.
Matek pdb $6 ebay, bangood. You could then upgrade the size of the main battery if desired.
4 years, things have moved on since then.
Even since I started 18 months ago.
 
How does the voltage effect the thrust of the motors? Would regulating everything to 12v help lower the power that the 4S li-po outputs?

Currently we just have our battery directly wired to the Esc's just through splicing the wires together. Is this a bad practice?
 
Jackson said:
You keep saying thrust, does that mean it just flies into the sky like a rocket?
Click to expand...
On face value, it sounds like you were way overestimating on the amount of power needed to lift the weight involved. Have you considered less powerful motors?
 
i'm a newbie with a particularly zippy micro quad (kingkong 110GT) and a flysky fs-i6. since i am new to both things, i have been having this issue also..

i have not authoritatively ironed it out yet, but so far, it really seems to be only a matter of adjusting the Tx settings. just lowering the throttle curve reduced the "idle" speed for me --- i don't understand why, because imo "zero is zero" when using a curve/transform/function, but it has indeed reduced the speed.
 
yay said:
i'm a newbie with a particularly zippy micro quad (kingkong 110GT) and a flysky fs-i6. since i am new to both things, i have been having this issue also..

i have not authoritatively ironed it out yet, but so far, it really seems to be only a matter of adjusting the Tx settings. just lowering the throttle curve reduced the "idle" speed for me --- i don't understand why, because imo "zero is zero" when using a curve/transform/function, but it has indeed reduced the speed.
Click to expand...
This is why I wish the transmitter and receiver manufacturers would make their products for both toy and hobby grade quads compatible. So that a receiver with better "fine tuning" capabilities as well as a similar transmitter, could be used with virtually any quad of a given size and grade. Model railroading adopted this standard decades ago. It's common sense, and cost effective.
 
If your throttle range is as I typed above then it's down to the pilot being to heavy on the stick. We all been through it. Only one thing you can do is, get used to it. Ha.
Nah the only other thing I can think of is change the throttle curve. This doesn't really fix it, it moves it around. Do you know about RC rates. It's a stick multiplier. Try lowering that aswell.
 
Nightham said:
How does the voltage effect the thrust of the motors? Would regulating everything to 12v help lower the power that the 4S li-po outputs?

Currently we just have our battery directly wired to the Esc's just through splicing the wires together. Is this a bad practice?
Click to expand...
Providing the motors & esc's are rated for 6S then power should make no difference. Tuning 6S is really hard from what I gather. By regulating to 12v is less out put of a 4S. The throttle would be a nightmare depending on the amps in that regulated 12v, it may only get you a 1/3 of the power on upto say quarter or mid stick then that your total throttle max. Definitely a no no. Splicing wires like that, why no pdb, with a clean 5v+12v out.
 
changed "end points" settings on my Tx from 100% to 50% for L-R, resulting in gentler, controllable-to-me movement, more like flying the e011. starting to get this combo to an overall flyable point (but my props are chewed up so waiting on mail).

my throttle breakpoints are down to like 0/5/11/26/50 instead of 0/25/50/75/100 still needs a gentle touch to not be a disappearing speck. not really much of a help since it seems like "everyone you talk to is using a different radio than you" ha. four years is a long time! whoop these issues into shape!
 
Bruce on RC model reviews made a 4 piece video on a zmr build.
I suppose most of it could still be applied.
But that's how he done the wiring by clumping all ground together & solder them up same with power. But then your talking regulators, step downs & resistors. Because of voltage spikes. Which can fry components. All this stuff has been streamlined down into little pdb that can handle 6S.
 
yay said:
changed "end points" settings on my Tx from 100% to 50% for L-R, resulting in gentler, controllable-to-me movement, more like flying the e011. starting to get this combo to an overall flyable point (but my props are chewed up so waiting on mail).

my throttle breakpoints are down to like 0/5/11/26/50 instead of 0/25/50/75/100 still needs a gentle touch to not be a disappearing speck. not really much of a help since it seems like "everyone you talk to is using a different radio than you" ha. four years is a long time! whoop these issues into shape!
Click to expand...
You probably did, but order like 10 sets of props. You can never have too many of anything in this hobby.
 
Not having an official PDB has nothing to do with his problems. For one he's not really talking about thrust, he's talking about erratic RPM and stick response. He needs to properly and carefully redo his LibrePilot setup, paying close attention ESC calibration. Actually paying close attention to everything damn thing.
 
Jackson said:
Not having an official PDB has nothing to do with his problems. For one he's not really talking about thrust, he's talking about erratic RPM and stick response. He needs to properly and carefully redo his LibrePilot setup, paying close attention ESC calibration. Actually paying close attention to everything damn thing.
Click to expand...

The whole thing has been recalibrated countless times. I've gone through the whole thing meticulously, looking over every step to make sure it was all done correctly.

I really don't think recalibration another time is the solution.
 
mozquito1 said:
If your throttle range is as I typed above then it's down to the pilot being to heavy on the stick. We all been through it. Only one thing you can do is, get used to it. Ha.
Nah the only other thing I can think of is change the throttle curve. This doesn't really fix it, it moves it around. Do you know about RC rates. It's a stick multiplier. Try lowering that aswell.
Click to expand...

I've adjusted the throttle curve through the program, and I don't see it making any major differences in when I ramp up the throttle on the controller. It still seems to raise the Rpm of the motors in a weird way (increasing Rpm up to 10% throttle, no change until 50-60%, then increasing after 60%)
 
Chuck said:
On face value, it sounds like you were way overestimating on the amount of power needed to lift the weight involved. Have you considered less powerful motors?
Click to expand...

I'm sure less powerful motors would help the problem, but that would be an extra 80$ or so to get similar motors after shipping.

And as stated in my original post, if you suggest buying a part, I would appreciate at least a link to an example.
 
yay said:
changed "end points" settings on my Tx from 100% to 50% for L-R, resulting in gentler, controllable-to-me movement, more like flying the e011. starting to get this combo to an overall flyable point (but my props are chewed up so waiting on mail).

my throttle breakpoints are down to like 0/5/11/26/50 instead of 0/25/50/75/100 still needs a gentle touch to not be a disappearing speck. not really much of a help since it seems like "everyone you talk to is using a different radio than you" ha. four years is a long time! whoop these issues into shape!
Click to expand...

It would be nice to be able to change settings from my Tx, but we got a good deal on our and it doesn't seem to be the immediate problem. I just wish the transmitter could have the kind of control that my laptop has while I have it connected to the software for calibration.
 
Jackson said:
You keep saying thrust, does that mean it just flies into the sky like a rocket?
Click to expand...

Yes, on the lowest "tick" of throttle on the Tx, the quadcopter is airborne. This is a problem that has been around since the start.

Does anyone know if there is a way to change how the different throttle amounts on the controller correlate to the Rpm/power supplied to the motors?
 
Nightham said:
I have posted these questions on multiple forums before and so far have yet to come across a straight answer as to how to go about fixing the problem I've been having with my first build.

This quadcopter has been earthbound for about 4 years now, and admittedly the first mistakes were due to a bad combination of parts that were too ambitious.

6S 5000maH turnigy Li-po
10x4.5 props
800kV turnigy motors
CC3D flight Controller
5 channel Tx/Rx
some generic but fairly sturdy frame
30A non-BEC ESC's
1500MaH Ni-Cd (for powering flight controller due to non-BEC esc's)
The quad is a bit on the heavier side, between 0.8 and 1.5kg's


Our initial problem? Far too much thrust, I was expecting a far heavier body and counted on being able to dial back the thrust enough. But the flight controller (LibrePilot) was not at all intuitive with changing throttle and power supplies to the motors. Many have suggested either buying a better flight controller or flashing new firmware onto it and using a different program, but the CC3D board was giving me all sort of problems with flashing new firmware and no guides I could find were that helpful at fixing that problem.

Eventually, I decided to lower my batter down to a 4S 5000MaH li-po instead, and should the thrust then be too low, I could add large 12" props to the frame to compensate.

The new setup is as follows

4S 5000maH Li-po
12x4 props / 6x3 props / 10x4.5 (there is an assortment for testing)
800kV turnigy motors
CC3D flight Controller
5 channel Tx/Rx
some generic but fairly sturdy frame
30A non-BEC ESC's
1500MaH Ni-Cd (for powering flight controller due to non-BEC esc's)
The quad is still a bit on the heavier side, between 0.8 and 1.5kg's

Here's were my most recent issues come into play

It seemed that even though I changed the battery from a 22.2v li-po (6S) down to a 14.6v li-po (4S), the thrust was still way to high to idle the propellers at minimum throttle. I've tried everything I can do on LibrePilot to remedy this issue, and I know the motors can have a lower RPM since doing the test where you find the lowest voltage at which the motor begins to turn. I just can't seem to find a way to make the lowest "tick" of throttle on the controller be the lowest amount of power sent to the motors.

(and as long as I'm listing problems with the current system, the throttle on it has been working really weird as well, where it goes up to about 10% throttle, holds at 50% until the stick reaches 50%, then ramps up more from there. I have tried adjusting the throttle curve but that seems to be of no use.)

I feel like this problem must be bigger as well, considering I saw almost no change in performance between the 6S li-po and the 4S li-po, but I'm at a loss as to why nearly cutting the voltage in half did nothing to affect performance.

I understand some of the hardware I'm using is old, I know there are better parts ion the market today, but I'm not going to sink any more money into this quadcopter unless there is a hopeful solution at the end of the shopping list. On batteries alone, I have spent 100$ just trying to troubleshoot and I have yet to make any progress since day one. If you suggest buying new hardware, please include a link and an explanation as to how that will help get things airborne.
Click to expand...
If you read his list, he doesn't list a pdb.
Hence him using a separate battery because of no bec to power it.
But must obviously be using a step down to power the fcb. That how it looks to me.
Maybe he not bothered about weight but.
Would make sense to use a single bigger battery for easier better CG placement.
 
Back
Top