Hi,

I am new to RC and have just built my Raptor 30. When I give throttle/collective everything is smooth. When the heli is just about to leave the ground the entire heli shakes violently! I am afraid to lift off due to the vibration. Any suggestions?

I have a Futuba 9CHP
Raptor 30
Futuba GY401 Gyro
OS 32 Engine

Thanks for your help!

Make sure your blades are balanced. Also is your engine running smooth. Im not a rappy owner but I have heard that rappys suffer from a shake on spool-up, not sure if this is true. Have you lifted it off the ground? If so does the shake stop?

Mine shakes when I'm at a high blade speed and just to start to get light on the skids. That is normal, if you are shaking bad while spoling up then your blades are unbalanced. I think it's funny to let my heli start to shake and then do a drag race style kind of start. It wouldn't hurt to have someone take a look at your heli to make sure your blades are not going too fast or too slow, and that your heli is set up correctly.

Thanks for your help. I checked the blades on a digital postage scale and they weigh almost exactly the same. The engine is smooth and not bogging down. Any other ideas?

from my experience it sounds like your throttle curve is off. Your headspeed is to fast for the weight you are putting on the heli. Move your throttle curve down a few points and try again. My machine did freak a bit but it was at lower rpms. By the time I got to take off speed I was past the harmonic that makes the machine shake.

I had that problem on my venture, after talking with a few others they suggested that I had to much pitch and not enough rpm. I doubted them but checked the pitch and sure enough to much, Im then leaned out my engine and guess what? No more vibration. Moral being recheck pitch, throttle curve, and mixture instead of driving yourself crazy as I did.
Thank heaven for the people on this site

I too am new to helis and have had the same problem. (I also have a Raptor) When it come to blade balance "almost exactly" is not close enough. Also, how about the blade CG? I admit it scared the s--t out of me seeing my heli shake like that but I finaly got rid of it.
Good Luck!

Thanks, I rechecked the weight of the blades and both weigh 3.9 grams. I am going to check the throttle curves this weekend and go for it.