Rig=RC timer dead-cat/tbs frame with motor gimbal
qbrain esc throttle set/ carbon props balanced.etc
4500 amp battery...to rear of frame to balance gimbal weight.
I have carefully followed Peter kings setup vids previously and had 100% success.
my problem on this new scratch build is the aircraft wants to tip forward on take off.
A low speed take off results in a forward flip higher speed gets me airborne.
but flight is not smooth very jerky especially...pitch in loiter which results in the aircraft rocking backwards and forward (swinging) or flying off.
I have re balanced the esc throttles but these all spin up at same time but holding the airframe with props on take off results in the stern end lifting before the front.
setup compassmot motors test have all been completed
main problem to resolve is level stable take off............
update pids tuned down from 6.0000 to 4.5000 has made it smoother peter has suggested re flashing qbrain with blue heli which I will give a go...
I have the same RCTimer spider quad, parts supplied from Peter King.
I have the PIDs etc set to the default values from Peter K and it's flying well.
Can you provide a screen shot of your 'Extended Tuning' page so I can see what is different to mine?
I find a quick burst of throttle is needed to get it off the ground. Too slow and it will roll over - and mine doesn't have a gimbal.
Having EXACTLY the same problem with my new hexa build. At first, I couldn't get enough throttle signal to the ESCs, but changing the THR_MAX parameter from 80 (8%) to 1000(100%) fixed that problem. Now it wants to tip forward and a little to the right. CG is checked good, balanced props, etc. I'm stumped.
To be fair i am now airborne again dropping battery size helped using a 2200ma battery 100% better so mainly weight related . So I will try bigger props in future and re balance CG.... when using 4500ma battery...
I am running 5S 5000mAh batteries (only a single stack now) with 15x5.5 CF props. That's about as big as it will go in terms of props. Which PIDs did you change? What are the Peter K PID settings referred to in Alan's post?
Attached is a screenshot of the settings i'm using.
Mine has 10x4.5 props however.
I see several right off the bat that are different from the default PIDs in AC 3.1. I wonder how they'd work in a hex.