@ ransomhall
The circle around a vertical axes can be because the blade screws are too loose. There must be some friction. Had the same problem on heli and someone corrected that for me…
I must replace a battery in a cheap heli. Will post a photo of the pcb. Saw the gyro on there…
But I don’t have a “syma” though…
Thanks for the tips guys. Syma seems to be the name brand that has produced a lot of knockoffs. Some of these are okay, some are total cr*p.
I have a Syma, it flies great. Very useful for giving people an idea of what it’s like to fly my quadrotor without handing over the controls for it. I’ve never had mine do anything odd, nor have I really ever had to trim it much.
EDIT: Yes, it does actually have a real gyro on it. You cannot stabilize on the axis the gyro is used for (yaw) with only two sets of rotating blades. There is some fairly active control theory going on inside those helicopters which is very apparent if you twist one in the air suddenly. Watch how fast it stops yawing when you let go.