Sricketts

I have rencently begun flying on a raptor 50, a few weeks ago i was flying the heli and crashed it. It was a minor crash, or so i thought at the time, the blades, the landing gear snapped and one of the oval stablizer bar contol rods cracked. so i replaced and reassembled the heli. When i went to do a test flight, on run up i noticed a relatively heavy vibration. so i stopped the heli and inspected further. What i have realised is that the pitch of one of the blades is at a negative attitude of about 15 degrees. ie. when the throttle is at idle the blade is 15 degrees pithched down, and at full throttle the ptich of the blade is all most at flat pitch. How do i fix this problem, is it possible that something is damaged in the main rotor hub? has anyone had any similar problems after a crash. Your help would be much appreciated.

K_Martin

Sounds to me like you may have bent either the double link, or the long link for the pitch control. These two links are used to adjust tracking, which is basically what your problem is at the moment. I presume you have already statically balanced the blades?
Measure the double links and the long links on each side, they should be close to the same. If not, readjust till they are the same, then try adjusting one blade (put a little 'x' on the blade and the holder, that way, if you take off the blades, you can put them back on the same way), turn it one full turn, check your tracking, if it's still off, adjust the OTHER side the opposite direction of the way you just did, then check tracking again. Keep going back and forth betwen blades till your tracking is set, and you should see that flutter (AKA vibration) disappear.
You should check to see if any of the links are bent first, if they are, either replace or straighten them.

BarracudaHockey

My Feedback: (11)

Before you go making any adjustments pull a blade off.

Take the remaining blade and put it straight out.

Put a hex driver on the bolt going into the spindle and turn it.

If the blade tip moves up and down your spindle is bent. Replace it. Make sure you lube it and the dampeners with silicon dielectric grease when you change it.

If the spindle is good start looking at double links.

Sricketts

Thanks Guys, I will try both when i go home, actually now that u mention it, when i was replacing the oval stabilier bar contol rod, i had had tried to disassemble the rotor head to replace the oval control rod, before i realised that if could fit over the blade grip without deforming, and i had been trying to loosed the 2 hex nuts at each end of the spindle, but to no avail. Is it possible that i messed up the pitch of the blade this way?

Thanks again.

sdavied

My Feedback: (4)

99.9% of the time, when you crash, you will need to replace the spindle and main shafts.