Hey everyone! I'm new to the hobby and just built my first quadcopter a few days ago. While I think I've fixed most of the problems I originally had, there's one problem in particular that I cant get down. Every time I raise the throttle, the quad understands and begins to go up. However, when I lower the throttle down, the quad doesn't recognize it and continues to go up on its own. I tested it out in betaflight and while in the receivers tab it shows my throttle going back down to 1000, but the motors still sound the same as it was maxed at 2000. I went into the motors tab and tested it using my transmitter and motors 2 and 3 will stay in the 1700-2000 range and won't go down when I lower throttle. Motors 1 and 4 stay at a lower throttle but I still won't have control of them. Could this be something in my configuration or PID settings? Maybe the firmware on the ESCs? Flight controller or motors? I've gone through so many youtube videos and a lot of them helped solve other problems but this one I just can't fix. I did notice one more thing although I don't know if it's related to the problem. When I go into the motors tab, the XYZ rates on the top right are high rates. From my understanding these rates are supposed to stay under 1%, mine are around the 2-3% range for all my motors AFTER arming. These are new motors straight from the vendor. They don't get hot to where I can't touch them either, so they seem fine to me but I don't know I am noob so I could be wrong. Anyways, I greatly appreciate the help, and thank you in advance! Happy Flying!
Heres a list of my components too just in case it helps:
When you are bench testing this is pretty much normal so long as disarm cuts them off you're okay. The vibrations from motors on the bench are adding errors in the gyro data and it has basically no control authority so if you tell it to go with the controller it will continue to try and correct even when you reduce throttle. Would say throw props on it (assuming disarm works as expected) and try it in a field (at least 10ft away). Arm it and push the right stick only no throttle make sure the roll and pitch do the right thing first just give it a little input for each direction on right stick. If it shifts around on the ground how you would expect then level things out again and give it a tiny bit of throttle till it comes off the ground. If something is backwards or prop is in wrong position you should notice during first step with right stick only but once you give it enough throttle it will either hover or flip out.
Also the motor control using the motor sliders in the motors tab should work like you're expecting low value = low motor speed but receiver input goes through PID loop and with no control authority it gets into a runaway basically.
I actually tried this after watching a Joshua Bardwell video and assumed it was just that but it did happen to me with props on and luckily I tested under a tree and so the quad hit the tree before getting too high and I just hit the failsafe. It actually did hover for a small amount of time but seconds later it started elevating and hit the tree. Even after I told the throttle to go down it still went up. I also did the roll test and everything works right there, it's just the throttle. I tried re-configuring my ESCs but that didn't work. Should I try re-configuring my motors?
Motors are dumb devices really (just wires and magnets so nothing to be calibrated there really). That sounds like some pretty crazy behavior though. What Betaflight version are you using now? It sounds like the FC is giving bad control to the ESCs if the ground testing works as expected but just when flying it has an issue. Make sure the escs and FC have a common GND that is well secured (I have seen weird behavior when no common gnd between FC and escs since signal has no common baseline, some signal may still get through but will be tons of noise too)
I have betaflight Configurator 10.4.1, I wanna reconfirm my findings because from what i saw today it definitely was weird but tomorrow im going to go to a more clear and open area where I feel more comfortable letting it go just to triple check but i think it will still happen. Lets hope for better results
The ESCs get some throttle signal and they do all the wizardry to spin the motors up to or down to that throttle speed from whatever the current speed is. The ESCs basically just use MOSFETs or FETs for short that are basically electrically controlled switches or "gates" and when the gate is open current flows through the mosfet ( so the esc opens one pair of gates to connect one coil of wire in the motor to positive and negative voltage then quickly switches to the next coil then the next and so on, the faster it fires the gates opening basically the faster it rotates the magnetic field and the magnets move along with it ).
The FC should have all the input and gyro data to tell each esc the right thing to do but sounds to me like this is where the problem is, would try flashing with slightly newer or older BF version. Be sure to use CLI/terminal in BF and "diff all" then save so can restore your config.
So I played with some settings in Betaflight and was actually able to solve my problem. I disabled air mode and anti-gravity and tested it out this morning. Throttle works perfectly now and lowers when I tell it to. I have a feeling it was actually anit-gravity that was giving me this problem but i'm going to continue testing both settings out to see why because I know it's wise to have those both enabled. I appreciate all the help and thank you again!
Glad to hear you figured it out. After watching some vids and reading about 4.0 to 4.1 upgrade saw some things about fixing runaways in there that started to make me suspect you had some FC that suffered that problem with 4.0. super glad to hear you got it sorted out though can always activate air mode with the same switch you go into angle mode with, generally if angle mode is off you want air mode on. Then can take off with it turned off and land with it (airmode) turned off since this is where I've seen it cause flip outs... Let us know if this helps too or if it was actually antigravity causing it would be good to know for future diagnostics (and guesswork )