BryFlyGuy67

Hello everyone. I did some repair work on my 450 V2 last night, including changing the main shaft. Now, when I spin up the Heli, I hear this cyclical noise coming from the main gear area. It is very noticeable as you spool up and then the sound disappears (or is drowned out) when the Heli reaches hovering throttle / pitch. If the bolt is through the hole on the bottom of the shaft and the shaft locking collar is secure against the top of the bearing block, there shouldn't be any issues with up / down alignment of the gear, right?

It almost looks as if the autorotation gear is not rotating in a flat plane and is riding up and down on the tail drive gear. I can't say that for sure, but that may be it.

Anything jump out at you that you want to pass along?

hennesseylord

make sure you push the main gear up before you tighten the top collar. when i took mine apart i had to loosen and tighten it a few times because somehow it kept having space when i pushed up. thats all i can think of atm.

glattica

Are you sure the copper ring is in place ? and the shaft is tightened with the locking collar. ? Also some triflow on these components helps considerably.

BryFlyGuy67

I am pretty certain that the answers to all of your questions is "yes", but I am just now headed down to check on this once again. If I can't find the problem, I'll post a video clip of a spool-up.

BryFlyGuy67

Here is video of me spooling up in te basement with Align Pro 325 mm blades.

http://s215.photobucket.com/albums/c...fvibration.flv

What the heck is wrong?!?!? [&:]

T/Aguy

i'm no expert by far but it seems that the main rotor slows down really quick in the video. how tight is it? does it spin freely??

juneebear

bryfly,

Did you check if there is any binding between your main gear and tail gear? Sounds like it.

stevennh

It sounds like you may be short a few teeth in your main gear. Rotate the main rotor slowly by hand and check for a flat spot or missing teeth on the main gear.

Steve

IM-A-PRO

Yes, definitely sounds like a missing or rolled-over gear tooth.

BryFlyGuy67

Okay, I just gave the Heli a lube job, let it sit for a minute, cleaned her up and put her back together. What had happened was that the shaft and main gear assembly were too far down. This was causing the slightly out of center autorotation gear to only barely make contact with the tail rotor drive grear and produce a cyclic sound.

When I put her back together, I made SURE that the shaft and main gear were pushed up firmly against the washer and lower bearing. Now, there is much more engagement of the autorotation and tail drive gears and the shaft spins nicely.

Now to put the tail back on and spool her up again to check for proper operation under load.

I'll post back when I confirm, but this appears to be nothing more than a n00b mistake. I guess it was a good exercise in troubleshooting, though!
[hr]

Here is a link to a new video I took after the adjustments. I show blade tracking as well.

http://video.google.com/videoplay?do...37028413&hl=en