A slight problem...

I had a question about my Belt cp V2. I'll start off by saying this heli is awesome. Once youve got it all set-up it is unbelievable stable! Im putting an arialvideo on youtube soon. \


Anyways, the only problem im having is that when Im powering down the motor my heli starts to vibrate then shake and bounce all over the place from some serious vibration.

I had a crash about a week ago and replaced the feathering shaft and the only thing I can think of is that the main shaft might be bent, but it flys perfectly when its in the air. So if anyone has a few suggestions or thoughts feel free to say them, Thanks.

every crash, the first thing you need to change, especially if you damage the blades is the main shaft. of course you wont be able to notice it as the heli spins really fast. but as it slows down it will give you a vibration resulting the damage of your bearings, shaft support and some screws might get loose. Always get a few parts extra such as feathering shaft, main shaft and tail rotor shafts. you this things always at perfect conditions, Also every now and then, check your screws after 7 to ten flights.

Blackrain0119 is right. After my first real crash, I stripped my CP v2 down, replaced all the 'noticibly' damaged parts (feathering shaft, fly bar, main gear, etc.) and checked the main shaft. And by checking I mean I pulled the retaining lug off and rolled it on a piece of smooth glass, looking for any real wobble or sound indicating it was anything less than true. I didn't really notice any.

However when I reassembled the heli and the head (and without blades on), I noticed it was doing the hula at low speeds telling me something was definitely OFF. And without the blades on, I knew it obviously had to be a head component or the main shaft...

Nothing was bent or out of shape in the head, so I went back to the shaft and tried a slightly different method for determining if it is bent, even slightly...

Lay the shaft on a flat surface and, with one or two fingers located at just one end of the shaft (either end, around the retaining screw hole), roll it slowly, while at the same time, tapping the other end of the shaft. If the shaft is bent, it will make a ticking sound when tapped as the bent end raises up and is tapped back down against the tabletop.

NOTE: You may need to give the main shaft a little attention with some sandpaper or steel wool to remove any excess screw lock from the area of the retaining lug, or any burs where the screws go through the shaft ends.
If the shaft is straight and true, it won't make any noise as you roll and tap.

In my case, when I found that the main shaft was indeed bent, I identified the the direction of the bend and how badly out of true it was, and found it to only be about the thickness of 2-3 sheets of paper (I could JUST slide 3 pieces of paper between the raised end and the table surface). This seemingly minute bend was the cause of my whole heli doing the shimmy-shake while spinning up.