So, i took off in stabilize mode

it shot up about 20ft straight up instantly and had to disarm and fall to the ground. i broke one arm and it is reprinting now. i am way overpowered with a 500mm frame, 2814 motors and 1237 props.

my minimum throttle is about 20% before the props spin. so, i have 400w down before i get lift. what should i use as ballast? a fishing rod and assistant till i get it tuned?

was stab mode the wrong mode? do i need to use alt hold? with ballast???

did you follow the ā€œarducopter tuning process instructionsā€ page step by step?

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Do you have a log (*.bin file) for this flight?

If he canā€™t fly it he canā€™t tune itā€¦

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It is obvious we have a terminology barrier to get past. What do you mean by " I have 400w down before I get lift"?

We need a COMPLETE parts list and how much the aircraft weighs with EVERY THING installed including the battery.
Also post some pictures of the aircraft and post the data flash log files, either .log or .bin.

Here is the log. i will upload some photos later.2021-01-24 13-32-34.log (926.0 KB)

Add to whatever else you have going on there a potential power problem. Your battery voltage sagged >2V to 10.3V during that take-off.

And as OldGazer pointed out this makes no sense.

BTW-What you experienced there may simply be typical Stabilize Mode behavior.

look at the current. it pulled 40A on that takeoff.

if this was normal STAB mode, does stab take off and shoot up to 30ft instantly? i didnt give it a chance to level off or anything since it was ā€˜out of my controlā€™ i killed it instantly.

Yes, I see that. The battery canā€™t provide the current required w/o a large sag, this was my point. Some is expected but 10.3V for a 3S battery is below what many fly to with a depleted battery.

so crappy batteries, need better ones to handle the load. got it! this bird needs heavier batteries anyway.

Here is the build.
All 3d printed body.
2814 1100kvā€™s
1238 props
5200mAh battery
Pixhawk2.4
Unsure of its current weight.

Hard mount the FC that should fit it.

Had you flown this in an assisted mode (AltHold, Loiter) before this takeoff attempt? I ask because the MOT_THST_HOVER value (.457) came from somewhere.

Had you flown this in an assisted mode (AltHold, Loiter) before this takeoff attempt? I ask because the MOT_THST_HOVER value (.457) came from somewhere.

only crashed it twice as i tried to get it to fly. what value should i knock that down to to let it retune?

.39 is default, that should do. Also, how did you arrive at the MOT_SPIN_ARM/MIN parameter values? Iā€™m not saying they are wrong just that most everything else looks to be at default. And before flying again definitely set the initial tuning parameters for the prop/battery size. Use the Alt>A plug-in in Mission planner and enter the values manually.

Using motor test. They dont spin till 19%, so i set them there to make sure they start reliably. Is that right?

Generally yes. But I wonder why they donā€™t start until 19%. What ESCā€™s are they? Why donā€™t you set these to 0 and try the motor test again:
MOT_PWM_MAX,
MOT_PWM_MIN,

Mystery 50A

will do once the printer finishes the new frame plate.

I thought you were suggesting No name ESCā€™s and you really are if these are what you have. I would suggest at the next re-build opportunity to replace those with some better quality BLHeli firmware ESCā€™s.
ESC

There are 2 versions of these ESCā€™s. Red shrink wrap and yellow shrink wrap :grinning:

Are 12-inch propellers the suggested size for this motor?
Any signs of heat at the motors?
I believe 10-inch (11-inch max @ 3S) propellers do better.
Did you do a successful ESC calibration?

Yes

No flight time to know. But it wouldnt hurt to order some 10"s. What pitch though?

Yuppers!