First drone build - Unstable, keeps dropping

joe809

New Member
The flight controller is flashed with Ardupilot, so I'm using Mission Planner for all configurations.

The issue I'm having is that whenever I push the throttle to the center or above 50% the drone takes off. However, without me moving the throttle up or down, it keeps falling down after reaching 2-3 feet then it lifts up again all by itself.

That's one issue. The other issue is that without me moving the roll/yaw, by just pushing the throttle to lift the drone higher, it keeps moving slowly to the right by itself.

r/diydrones - Drone won't stay stable, keeps dropping
In Mission Planner, FailSafe, when I put the throttle to about 25% you can see that Motor 1 is speeding a lot faster and Motor 2 is slowing. They should all be close to the same speed.


Drone specs:
Kakute F7 mini
4 in 1 Tekko32 ESC
3s 5200mAh Lipo Battery
HMC5883L Compass

Here is a Google Drive link to two Mission Planner .bin logs files from two flight tests I did.

https://drive.google.com/file/d/1_1JFMpIua2FVU2DUvvilG9Tyo38k-R1T/view?usp=sharing
 
A. Combination of it fail safeing or browning out, and then.. gravity takes over. The flight controller is browning out from voltage drop caused by throttling up and supplying all those motors with serious amps. Bungee cord the quad down to the top of a step ladder, then throttle up to 10% and hold for 10 seconds. If ok, try 20%, and hold. 30%, and hold. 40%, and hold. At some point you'll find where you brown out and flight controllershuts down, if that's the case. In a correct power supply setup, you should be able to throttle up to 100% and hold for 30 seconds, and no brown out.

B. Needs leveling out on a table first (quad) with a bubble leveled table, or trimming (plane). You do this while connected to a computer while setting up the values in your flight controller configurator.

My pro tip is do not try and test fly it like the self proclaimed "experts" tell you to do, line of sight hover first.... in your kitchen, garage, driveway or backyard.... all very bad choices. I've seen guy say oh, you need to test it LOS first, and I want to face palm. It's actually very hard to fly a quad LOS, as it will immediately start to drift off in any direction given the slightest amount of wind, and unlick a plane, when things get confusing, it's hard to tell which way is nose first.

Instead, take it out to the biggest widest open space you can find imaginable, a football field, farmer field, etc... stick it in ANgle mode, and start right off the bat FPV but just in case be ready to hit that disarm switch. I can fly an out of control quad that is not calibrated FPV doing weird stuff, you just compensate in the other direction with the sticks, but I'll be derned one could fly a wacky one LOS. You can immediately tell in the goggles which way it is yawing wrong, but not so fast LOS. At least that's my opinion.

As soon as you can, get away from flying in Angle mode for good and permanently, as it's trainging wheels, and only useful for the most inexperienced of pilots, testing a new quad, or still photography work.

If you haven't spent at least 500 hours in a quad simulator first, then you need to set all this down on a table, do not touch it further, and back the F up, and do that first. 1,500 hours is actually a better number. Play it like your favorite video game, and the hours will fly by.

choppergirl
 
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