techrtr

Is it normal for a Draganflyer to constantly pogo up and down with the throttle steady? If I fly mine more than a couple of feet off the ground, It will maintain height for a few seconds, then drop, hit the ground, bounce back up, maintain height for a couple of seconds, then drop again. If I try to anticipate the drop and give it more throttle, it drops, then shoots up. I back off the throttle, it drops again, and the whole thing starts all over again. I've also noticed that sometimes when I fly with TI on, it pulls really hard one way and I have to compensate with stick. If I let go of the stick, it wants to shoot one way, even though the trims are set right to fly without TI.

XStroX

I just asked the same question the other day. Its under the "Low Height Oscillations" thread very close to this one.

Stro

techrtr

Yeah, I read your earlier post but mine does this 15 feet in the air when it's free of ground effect. It's pretty unnerving to have the thing suddenly drop then shoot up, especially when you're under power lines. I've had a couple of wicked crashes after the copter did a bounce, got kind of high, and then got away from me. Not sure if this a typical flight characteristic of all helicopters or just something draganflyers tend to do.

jodaboda

I have the same problem exactly; it's almost like exaggerated thermals. Let me know if you figure anything out.

techrtr

I've gotten used to it. Don't think it has anything to do with the copter, it's caused by rotor downwash. Keeping the DF moving prevents a downward flowing column of air from forming under it.

Odyn

this came up in a thread of mine as well:

http://www.rcuniverse.com/forum/m_4886683/tm.htm

laceycopter

Sorry I moved it to DF randomly loses altitude .... and I couldn't delete this.