A Tlog is of minimal value for troubleshooting this. Post link to the .bin Flight log from the flight controller.
The flight log is a waste of time. I found an old post on here that had the exact same issue as the above but it’s 2 years old, hoping someone can lend a hand. I think you also commented on some of the posts.
Link here:
It might be a waste of time for you… Good luck.
Apologies, I meant it was a waste of time purely because it never flew only 1 foot off the ground. I looked yesterday and I’m pretty sure that I’m getting 50% throttle output for 100% input on transmitter. I will post later if you think it may be of any use. As I said above I found an old post that is the exact same issue I’m having here. The fix there was to downgrade firmware to 3.3.3 but the board won’t let me do that? Mission planner only allows me 3.2.1 or any of the 4.x versions which don’t fix my problem. I’ve been trying everything I can think of for days but to no avail. As above, will post the .bib from yesterday later on.
OK, got it. The Parameter file can be extracted from a Flight Log even if there is not much in it and that can often be helpful. If it’s a typical Pixhawk 2.4.8 you should be able to flash the latest Stable (4.0.5) no problem. You for sure don’t want anything else. Update Mission Planner to latest Beta (button on the Help Screen) before attempting to flash it again. If this doesn’t work try QGroundControl and select Arducopter like this:
Got ya, will try that. Yes I can flash 4.0.5 on no issue but that gives me the 50% throttle issue. Will download the log shortly and post to see if you can take anything from it. Sorry for the misunderstanding above.
Post shortly and thanks again, I really appreciate your help.
As promised .bin file here. Hope you can give me some insight.
Have updated MP this eve toi the latest Beta. Uploaded 4.0.5 again. Will recalibrate tomorrow and try again. Will update you on the findings tomorrow. Thanks.
RC2_TRIM (elevator) is at 2005. Is the Tx trim sliders centered and have you done a radio calibration? Fix this and then post a log of it actually flying. Even if it’s just a short hover.
Ok will do tomorrow. I’ve calibrated radio, pixhawk, ESCs, etc numerous times. But can do it again and eliminate.
Well, when the command to the Front Motors compared to the Back Motors look like this some things become obvious. The value of a Flight Log even if it hasn’t left the ground 
. Ok so going by that is it not telling me that for 100% throttle input signal from my transmitter I’m not even getting 50% output? The pitch and roll channels are giving me 100% signal?I didn’t touch yaw so channel 1 is showing me 1000/1100 us?
Those are commanded motor outputs (RCOUx).
It’s being commanded to Pitch forward (full output to rear motors) because the elevator Trim is at full input
From your parameter file
RC2_DZ,20
RC2_MAX,2005
RC2_MIN,982
RC2_OPTION,0
RC2_REVERSED,0
RC2_TRIM,2005
Have you fixed this?
I’ll check but I’m pretty sure I have. That file may have been taken after I reset and reflashed my radio. It reverted to mode 1 which reversed pitch and throttle. Sorry I may have uploaded the wrong .bin file. I’ll be back at bench shortly so I’ll run again and send you that file instead as that’s the way I’m setup after changing radios to mode 2.
Here is link to latest log. Again this is no props on and tested on the bench. Any help again, greatly appreciated.
I uploaded 4.0.5 firmware to the Pixhawk and prior to that I updated the MP firmware also to the latest. Same issue again. 0-(approx)50% seems to have full throttle range on the drone, 50-100% change on my transmitter has no change on motor speed, and brings in a potential thrust loss 3 alarm each time. Same issue remains.
It shows Loiter mode not engaging due to the GPS not registering but this is because I didn’t leave long enough after the firmware upgrade to pick up satellites but when I do switch into this mode the motors slow and indicate a crash.
Thanks again.
Put props on it and fly it. You can tell very little from it sitting on the bench with no props. Motors are turning and in which direction is about it.
You can use Motor Test function in Mission Planner to test unpropped motors.
Latest .bin file attached. I don’t think it’ll be of much use. Same again, got about 1 metre off ground in stabilise, with drone uncontrollable. With the full throttle range between 0 and 50% its impossible. Switch to loiter and the quad just lands, t]it won’t loiter. This all worked fine 2 months ago and honestly don’t know whats gone wrong. I used to be able to take off easily in stabilise then switch to loiter and worked a dream. I don’t think I can get any better flight log as this is as long as I can stay in the air which is all of about 5 seconds. It may be time to find a new hobby…
There’s a few issues.
Firstly you take off before there’s a 3D Fix and that messes up altitude.
Set these to wait for a proper 3D fix before being able to arm:
FENCE_ACTION,3
FENCE_ALT_MAX,50
FENCE_ENABLE,1
FENCE_RADIUS,100
FENCE_TYPE,1
People get impatient and want to launch immediately, but best to wait.
Set up proper battery monitoring, the voltage and current readings tell so much - then you’ll also need to configure these:
MOT_BAT_VOLT_MAX
MOT_BAT_VOLT_MIN
BATT_FS_CRT_ACT,1
BATT_FS_LOW_ACT,2
Some of this gets configured if you enable and calibrate (or at least check) the battery voltage and current monitoring, then connect the quad to MissionPlanner and press ALT A , plug in your cells and prop size and accept all suggested values except INS_GYRO_FILTER - leave this one at 20.
Motors 1 and 2 (CCW) are working much harder than 3 and 4 (CW) indicating motor mount twist or frame twist. Motors 3 and 4 are physically causing yaw and motors 1 and 2 are trying to fight it.
Fix all those things then try another test flight and share the .bin log
Thanks for the pointers, will work on the above and post the flight log when I get to it. I also need to start a new thread related to the throttle issue as when this occurred at the beginning it was a yaw issue but as time has progressed it’s become an issue where my throttle is only operating on a small range. The first post in the thread doesn’t relate to this but a few posts in it does.
The above points are absolutely valid though as battery monitoring is on my list of things to do so will work on that and repost here. Thank you again for the help.
You can also set these too:
ATC_THR_MIX_MAN,0.5
PSC_ACCZ_I,0.70
PSC_ACCZ_P,0.35
but dont rush into thinking they’ll fix everything, follow the rest of the issues through and you’ll get a better flying aircraft in the end.
Here’s the tuning guide that everything we discuss is based upon:
https://ardupilot.org/copter/docs/tuning-process-instructions.html
That MissionPlanner plugin (Alt A) will do a bunch of it for you and then we have to see how it flies to know what to do next.
Also, I’d probably do the RC calibration again, check that when you pull back the Pitch stick that the green bar rises, push forward the pitch stick makes the green bar go down. The other axis are more “logical”, the green bars will move the same way as the sticks.
After that redo the all-at-once ESC calibration:
https://ardupilot.org/copter/docs/esc-calibration.html?highlight=esc%20calibration#all-at-once-calibration
…then everything I said before!
Will do all the above and see. I’ve gone from a fully functioning drone to something that I can’t control and originally all on default settings. Will do above and get back with flight log. Thanks again.