Rattling noise at low RPM

[pvande]

Recently I've started hearing a rattling noise whenever I start up my Raptor 30V2. It sounds like the tail belt is beating itself to death against the tail boom.

As soon as I pick up RPM it disappears - at about 1/3 stick on the throttle. While flying there is absolutely not rattling.

The tail belt feels like it is under tension - anybody experienced this before or have ideas where to look for the problem...

[Badger50]

Does it go away when you hold your tail rotor push rod. Sometimes at idle it will vibrate the hell out of the pushrods inside the tail rod slides. It does the same thing on my rap 90, so I just twist the rod guids a little to take the slop out of the guids. Make sure to also check to see if the rod is vibrating against the tail case assembly. The reason you probably don't hear it when your flying is because your heli is not solid on the ground, which will magnify all vibrations. Hope you find the problem.:lol:

[Skarn]

Could it be that at low headspeed the sound is lower and you can actually hear your knees rattling against each other? LOL!

Ok, sorry, I had to do that ;)

I hope you get your issue resolved.

Skarn

[Maxime30]

I've seen this happen when the bolt that goes trough the gear system and main shaft is loose. Make sure this bolt is snug (but not too tight, as it could break during flight).

[pvande]

Maxime - thanks for the idea. I'll check it out this weekend.

Skarn - didn't think of that and tested the idea. After identifying both the knocking knees and teeth chattering I still have the same problem..:YeaBaby: