My Quad Flew like a Rocket sky high by itself! please help
« on: November 24, 2017, 01:25:18 pm »
Hello every one

please help me today i tested my quad, because i changed motors from racerstar BR1806 2300KV to EMAX RS2306 2750KV
i was using same PIDS, with the racerstar BR1806 2300KV my flying was ok no problems at all actually its very smooth,
but i bought the EMAX RS2306 2750KV so i had to try it out.

so after installing the EMAX RS2306 2750KV to my quad i tested it outside, i try to hover it and it was fine its smooth then
i try to land it and it bounced to the ground and what happened after the bounce it flew to the sky so fast and high wow! thats
so dangerous please help me fix this, in my previous setup when i bounce sometimes on landings it kinda recoils but not like the emax
that is so violent and so fast!

heres my setup

DYS xcite 250
20amp esc
EMAX RS2306 2750KV
emax avan s
2200mah

is it the PID setting that's causing it? if yes how come i dont experience it in my old motors?
please help me what to tune down to get rid of sky rocketing when bouncing on landing
i dont want to hurt somebody because of it :(

Re: My Quad Flew like a Rocket sky high by itself! please help
« Reply #1 on: November 25, 2017, 05:45:39 pm »
Does it still fly well, just need to avoid bouncing it?

What board is this and what flight mode and thrust mode are you using?

I have seen this a little before, but it never goes anywhere.  A few CM / inches at most.

Where I have seen this more is when using Altitude Hold/Vario thrust mode (or GPS modes) that use the baro and the baro is not properly shielded from prop blast.  Once you hit a high level of prop blast the extra pressure makes the baro think it is too low, so it makes the motors run even stronger which makes it think it is even lower (repeat)...

A video would be great.

Re: My Quad Flew like a Rocket sky high by itself! please help
« Reply #2 on: November 26, 2017, 04:34:17 am »
Hello Cliff

yes it does fly very good to be honest, its just that when i bounce on the ground (which means my throttle is low) BOOM it sky rockets up high.

its a cc3d im in attitude mode

thanks

Re: My Quad Flew like a Rocket sky high by itself! please help
« Reply #3 on: November 26, 2017, 05:04:34 am »
I bet you have a problem that if you yaw quickly back and forth that it climbs a lot then too.

These are somewhat normal small problems that are made worse by ESCs that don't do LightDamping or COMP_PWM.

Re: My Quad Flew like a Rocket sky high by itself! please help
« Reply #4 on: November 26, 2017, 01:52:03 pm »
Hello Cliff if you are saying its my esc thats good because im planning to replace my 20amp esc's soon with 30amp esc's
if esc is the issue, if not what could cause it? yes you are correct there are times that i get climbs a little when yawing fast

any esc you can recommend for my emax rs2306? im running emax avan props 3 blade 5x65

is it possible that the rapid climb was caused by my I gain? because when values of my I gain is 800 when i bounce the crazy fast climb
happens when i tune down to 100 I gain then when i bounce it climbs but not so fast and not so high its kinda normal,
but whats weird is this happened when i changed from 1806 motor to 2306 motor, in the 1806 motor the I gain can be crazy high
and when i bounce my quad accidentally to the ground when landing it bounce normal nor crazy rapid climb.

Re: My Quad Flew like a Rocket sky high by itself! please help
« Reply #5 on: November 26, 2017, 05:03:42 pm »
Any time you change the lift of the motor system (prop (sizexsize, type, brand), battery cell count, motor (KV mainly)) you should consider retuning PIDs if you want best performance.

From your description, it sounds like you know that your PIDs are too high.  Does it ring (decreasing oscillations) at all?