Vibration at lift off!

[Superbike1]

I finally spun up the dragonus today to try and trim it out. When I get it off the ground, the skids start to vibrate and shake real bad. Other than that it was all great. Tracking is good and it floats, to a degree. It just vibrates as soon as I climb into a hover. Any Suggestions? I am at a loss. Everything is smooth until liftoff and a hover is acheived. Blades are balanced. Anything?

[Superbike1]

Anybody?

[marty_one]

do you have a different set of blades to try? does the vibrations stop at any point?

[JustPlaneChris]

Watch the center of the head block during spool up or spool down... see if it's wobbling in a little circle instead of being perfectly true...

[DeadTom]

+1 on the wobbly plastic headblock as JPC has eluded to above.
Do yourself a favor and get the aluminum upgrade headblock it is well worth it.
The aluminum swashplate is another great and well worth it upgrade.
DT

[rc247]

I have the aluminum headblock as well but it seems like it doesn't want to sit true on the main shaft. I've tried to get as straight as I could but it's still got a little wobble. Vibe goes away once it's up to speed. Anyone else have this prob w/ the aluminum headblock? If so
got any tricks to get it on alittle straighter? Sorry for the hijack on your thread!

[Butuz]

Try doing up the jesus bolt on the headblock a bit tighter? I had this once where the ally head block seemed a tad loose on the shaft - if you strip the head right down to the head block you may be able to wobble it yourself. I thought it was tight enough but clearly it wasnt so I closed my eyes and put another half turn on the jesus bolt and hey presto true as a die.

It's now been running fine for about 6 months after tweaking that bolt.

Butuz

[Superbike1]

I turned my throttle curve up a little and that fixed the vibration. I actually hovered it and tuned it today for a few minutes but now it oscilates in a 6 foot circle and I find I am try to hold it still and correcting continuously. I think it is still turning too slow. I have a 3500kv motor on it and I didn't want to over power the plastic head at full power. I had my original throttle curve at 55 percent and then I turned it up to 65 percent. It hovers nice and smooth except for the osscillation. I am not sure what the head speed is or what it can be on 3500kv 13 tooth 11.1v ,and I am just trying to get it to hover well and do some scale type flying around. Thanks for all the help and ideas from everyone. I think I will get t set up a little better in regards to weight distribution and then I am going to go flybarless with a sk360 or the likes.
Dean

[rc247]

Originally Posted by Butuz

Try doing up the jesus bolt on the headblock a bit tighter? I had this once where the ally head block seemed a tad loose on the shaft - if you strip the head right down to the head block you may be able to wobble it yourself. I thought it was tight enough but clearly it wasnt so I closed my eyes and put another half turn on the jesus bolt and hey presto true as a die.

It's now been running fine for about 6 months after tweaking that bolt.

Butuz

Thanks Butuz! I'll try that.

[DeadTom]

Originally Posted by Superbike1

I turned my throttle curve up a little and that fixed the vibration. I actually hovered it and tuned it today for a few minutes but now it oscilates in a 6 foot circle and I find I am try to hold it still and correcting continuously. I think it is still turning too slow. I have a 3500kv motor on it and I didn't want to over power the plastic head at full power. I had my original throttle curve at 55 percent and then I turned it up to 65 percent. It hovers nice and smooth except for the osscillation. I am not sure what the head speed is or what it can be on 3500kv 13 tooth 11.1v ,and I am just trying to get it to hover well and do some scale type flying around. Thanks for all the help and ideas from everyone. I think I will get t set up a little better in regards to weight distribution and then I am going to go flybarless with a sk360 or the likes.
Dean

Are you in normal mode or in idle up? I would kick up your throttle curves even more or pick up a tooth on the pinion. If you are chasing it in idle up like you are saying then I would get the headspeed up a little more until it will hover nicely with out too much input.
DT