I'm just curious if the Hero FC is somehow limiting full spoolup. Have you tried disabling all the auto functions (GPS, altitude/range limatations, etc.)? Were your thrust tests performed while connected to the Hero?

(17-May-2017, 09:15 AM)Keyboard Kid Wrote: BTW, please let me know if I start to wear you all out answering questions.

KK

Haha, no, not at all, in fact i see it as a honor if i can be of help to you. So, please, keep asking.


Regarding the motors getting barely warm, that's difficult to interpret. Could be that it's fine since they run at pretty high throttle, but it could also be a sign that there's some noise in the gyro. With the fast looptimes and motor protocols typically used in betaflight, oscillations can be so fast that they are not noticeable at all - they might not even get through to the props due to motor/prop inertia, instead it's just the escs being commanded to continuosly accel/brake within milliseconds which means a lot of energy is wasted for nothing.

2 things you could try:
A) increase the amount of TPA just a tiny bit, i.e. instead of 0.10 which is default, try maybe 0.15.
B) lower the lowpass filter frequency a bit, maybe down to 80Hz or 70Hz (in PID tab -> filter settings). The lowpass filter in recent betaflight versions does not cut very steep, lowering it might help a bit even if you feel things are running smooth.

I also tried to look up the Hero FC, but i did not find any info wether it offers internal flash memory or SD card slot for recording flight logs? If it did, you could at least use the blackbox logging function to check out gyro noise etc.

(17-May-2017, 01:29 PM)Keyboard Kid Wrote: Unseen, I must say I am still struggling to come to grips with this lack of power.

With regards to your comment above if the quad is pinned to the ground by the 6kg AUW then there is no forward movement and in theory, or at least the way I see it, thrust should equal 4 x 2.1kg at that instant. Yes I agree that once forward movement has started thrust will drop. But at the moment 4kg pins the quad to the ground, which is 1kg per motor. It just does not make sense.

Is there a possibility that my throttle range is not set correctly. According to Betaflight I have set the pulse width to the optimum pulse width range but I have never set it up using the joystick commands. Would this make a difference?

I just find this lack of a data log so annoying. I need some hard data on voltage current, RPM etc. I am not used to working like this.

Sorry for the late reply, I didn't realise you were still using your intro thread for this discussion.

Once you had set the range of the throttle in Betaflight so that it goes from 1000 to 2000, did you then calibrate the ESCs using the Motors tab in Betaflight?

The ESCs need to be calibrated to the throttle range if it is changed at all and that calibration must be done against the flight controller.

If the calibration isn't correct, that might explain not getting full thrust at full throttle.

(17-May-2017, 05:23 AM)Keyboard Kid Wrote: So my new design parameters are 5.8kg AUW with a reserve thrust of 600g giving me an all up thrust of 6.4kg.

Sorry, but it doesn't work like that.

If your AUW is 5.8kg, then you must be able to achieve (5.8 / 4) 1.45kg thrust per motor at 50% throttle.

(18-May-2017, 10:36 AM)unseen Wrote: Sorry for the late reply, I didn't realise you were still using your intro thread for this discussion.

Once you had set the range of the throttle in Betaflight so that it goes from 1000 to 2000, did you then calibrate the ESCs using the Motors tab in Betaflight?

The ESCs need to be calibrated to the throttle range if it is changed at all and that calibration must be done against the flight controller.

If the calibration isn't correct, that might explain not getting full thrust at full throttle.

Hi Unseen, no I did not recalibrate the ESC. I will do so in the morning.
Also, how do I swap this thread over to 350mm?
Regards,
KK

(18-May-2017, 10:41 AM)unseen Wrote: Sorry, but it doesn't work like that.

If your AUW is 5.8kg, then you must be able to achieve (5.8 / 4) 1.45kg thrust per motor at 50% throttle.

Now you tell me. I needed to know this 12 months ago.

(17-May-2017, 07:47 PM)- fftunes Wrote: 2 things you could try:
A) increase the amount of TPA just a tiny bit, i.e. instead of 0.10 which is default, try maybe 0.15.
B) lower the lowpass filter frequency a bit, maybe down to 80Hz or 70Hz (in PID tab -> filter settings). The lowpass filter in recent betaflight versions does not cut very steep, lowering it might help a bit even if you feel things are running smooth.

I also tried to look up the Hero FC, but i did not find any info wether it offers internal flash memory or SD card slot for recording flight logs? If it did, you could at least use the blackbox logging function to check out gyro noise etc.

Hi FF, I did increase the TPA setting from zero where it was set to 0.15 as suggested but there was no noticable effect in flight.

The filters as set in the Betaflight at the moment are all over the place varying from 50 to 450. Beta Wiki suggests 100 as a default so I need to start working towards that figure over the next few flights.

FF, what are typical values for the PID settings? As purchased the P settings varied between 43 roll, 57 pitch and 80 yaw. Beta Wiki suggests working to the following formula P = as much as gives stable flight. I = P/2, D = P/5. Using this formula as my guide I am currently flying with P = 90, I = 45, D = 18. As stated previously the quad flies smoothly with no apparent odscillation or snap-back and is quite controllable.

I will say however I cannot take my hands off the controls for more than about 10 seconds after which it will start to drift in one direction or the other. In other words I have to fly it all the time. Is this normal or have I not yet achieved optimum set-up?

Betaflight filter recommendations are meant for nimble miniquads, not for heavy ships like yours. You didn't mention filters before, so if you had lowpass already at 50Hz before it would mean that this is not likely to be an issue. It's ok to go that low on a bird that's not meant to flip and race nonstop.

Regarding PID, i'd say leave P where it is now, but increase I to get rid of drifting. That "formula" you've seen is probably quite old and I-term behaviour changed a lot in recent versions. No problem to go higher there, i've seen examples of I-term as high as 85 even on small quads.

(18-May-2017, 12:50 PM)Keyboard Kid Wrote: Also, how do I swap this thread over to 350mm?

I can move the entire thread for you if you like.  Just let me know.  (If I do, I would suggest that you edit the title of the thread to be more informative.)
Scotty

(18-May-2017, 01:12 PM)Keyboard Kid Wrote: I will say however I cannot take my hands off the controls for more than about 10 seconds after which it will start to drift in one direction or the other. In other words I have to fly it all the time. Is this normal or have I not yet achieved optimum set-up?

Just like a real rotorcraft, unless you are flying in an assisted mode with GPS and all the bells and whistles, the flight controller has absolutely no idea of your position in 3D space. As wind and turbulence acts on the craft, it will move with these disturbances.

In manual flight modes, it's completely up to the pilot to achieve stabilisation of position.

If you are using a self-levelling flight mode, the accelerometer data will be used to correct attitude if the craft is not level and you have the pitch and roll sticks at neutral. If you are flying in 'rate' or 'acro' mode, then all the flight controller does is use the gyro to ensure that the rate of rotation around each of the three axes remains as you are commanding.

Hovering a quadcopter at a precise altitude and position is actually much harder than flying around!

(18-May-2017, 12:53 PM)Keyboard Kid Wrote: Now you tell me. I needed to know this 12 months ago.

It's the way these things work. Achieving movement on any of the three axes is achieved by using differential thrust on differing combinations of motors. If you use up all the available thrust just to get into the air, there's nothing left over to control the craft!

I've been looking at that time machine to go back a year and have a good chat with you, but I've not been particularly successful.

(18-May-2017, 06:50 PM)unseen Wrote: It's the way these things work. Achieving movement on any of the three axes is achieved by using differential thrust on differing combinations of motors. If you use up all the available thrust just to get into the air, there's nothing left over to control the craft!

To be a bit more exact, it would remain controllable, but it would start to lose height.

(18-May-2017, 09:30 PM)fftunes Wrote: To be a bit more exact, it would remain controllable, but it would start to lose height.

To an extent, that's correct, but it's very dependent on what the flight controller is able to cope with when there are no reserves left. A loss of altitude is the best case failure mode.

(18-May-2017, 03:18 PM)sloscotty Wrote: I can move the entire thread for you if you like.  Just let me know.  (If I do, I would suggest that you edit the title of the thread to be more informative.)
Scotty

Thanks Slo, how about "Heavy Lifters"? Or some title more suitable to your forum.

Now the big question, will all my new found friends come with me?

We are finally getting down to the sort of discussions that I had hoped for and I love it and do not want to lose it.

Thanks everybody.

KK

(18-May-2017, 06:50 PM)unseen Wrote: It's the way these things work. Achieving movement on any of the three axes is achieved by using differential thrust on differing combinations of motors. If you use up all the available thrust just to get into the air, there's nothing left over to control the craft!

I've been looking at that time machine to go back a year and have a good chat with you, but I've not been particularly successful.

Unseen, I have been working on that time machine for years in order to clean up the messes I have made of various projects over the years. I am very close but my quad project is eating into my time for that project. Perhaps one day when this project is cleared I will finish it off.

If so you will be the first to know