g20 help

[jjoos99]

I have been fighting a tail vibration on my new radikal. I have tried new tail blades, tail hub, new tail bearings, new starter shaft bearings. I was spinning the head over today and am hearing gear mesh noise where the main tail gear is meshing with the belt drive gear. Looking closer the main tail drive gear is actually moving up and down as it is turned where is meshes with the belt gear. Can someone take a look at theirs and let me know if this is normal. I would think that maybe at high speed it might be causing my vibes. What do you think
thanks
Jeff

[Lieutenant Dan]

that gear should not be moving up and down, do you have a manual, there should be 2 small washers/ 1 on each side of that gear, or it may be that a bearing is shot,
ether way/ rather that's your problem or not you need to fix that

[jjoos99]

The main tail drive gear isnt moving up and down in the center but out at the teeth as if the gear is warped or not seated properly on the hub. This heli was partially built when I got it and it was new. I probably need to pull the gear out and check how it is mounted to the hub.
Jeff

[Billme]

Also, put your thumb on the clutch bell, and see if you can move it side to side, since this is a used heli...If there is play, then you need to drop the clutch and put some tape around the bearing to make it tight inside the housing..

[Tino Tweak]

Saw about yr vibration in the tail.
I had it with my G20 and some other guys as well here in the Netherlands.

We solved it by using at complete tailrotor of the Trex 600.

Grtz, Tino

[Mr.HillBilly]

Both of my birds you can hear gear noise, if you hold one gear there should be a little bit of slop. Every bird I have ever had with molded gear, the gears wobble a bit. How I set my mesh is I take a strip of paper in between the teeth of both gears then press them together, lock down the tail and spin the paper back out. I do the same with the clutch.

As for checking the clutch bearings goes you really need to drop the motor so you can try wobbling the bell around. When the bell is still on the clutch it is hard to tell how much movement you are getting. I had a weird vib that took me for ever to figure out, when I would have the motor loaded everything sound good, but as soon as I would go to a unloaded head I would hear a bunch of noise. Lower bearing on the clutch was completely gone.

If you do pull the bell all the way out, hold the top bearing and spin the bell. I some how warped a bell and it had a good wobble when spun holding it from the pinion side.

Does the vib. stay when loading the head also or just in a hover.

If you have not done it yet, I would pin the front and back cases of the tail so they can not slide on you. Do not do both sides until you get your belt at the right tension.

[jjoos99]

Will the drive gear wobbling cause a vibration. I would guess it is moving up and down 1/8 -3/16 in where it contacts the tail belt gear. this heli is basically brand new other then maybe a dozen or so hover flights. I just replaced all the bell and starter shaft bearings because I thought one was alittle bit rough. The gear mesh noise wasnt bad at all till it got to the same spot as the rotor head was rotated. That is how I actually found the main tail gear moving up and down. This heli has been so frustrating, I havent gotten to fly it other then hover flights.
thanks
Jeff

[MotorRotor]

Originally Posted by jjoos99

........... This heli was partially built when I got it and it was new. I probably need to pull the gear out and check how it is mounted to the hub.
Jeff

IMHO, any heli that one receives that has been "partially built" by someone else, should be disassembled and reassembled to insure it was properly assembled in the first place. Specially a relatively complex heli like a gasser.

What version of the Radikal G20 is it, the G-10 framed LT, the G-10 framed HD, or the carbon framed LT?

Do you have any experience with gasser helis? I guess what I mean is if you have ever assembled a heli that uses and IC engine and know how to dial indicate the motor shafts etc.

[Lieutenant Dan]

Originally Posted by jjoos99

Will the drive gear wobbling cause a vibration. I would guess it is moving up and down 1/8 -3/16 in where it contacts the tail belt gear.

(1/8 -3/16) sounds like a lot to me, both my drive gear and main gear only wobble about .010/.015 each, I would replace that drive gear myself, I have to wonder if that heli had crashed and then rebuilt

[Mr.HillBilly]

Glad to hear someone has gotten flat gears. All of my gears have wobbled more than a 1/8". My main gears are always warped, after they get spun for a bit the mesh gets smooth and less noisy.

Anyway you can get us a vid. so we can she what your bird looks and sound like. From idle though hover would be best. All of my birds have a bit of a vib. now and then but you should be able to get most of themt smoothed out.

Other thought, have you checked the motor shaft to see if it is warped? Most gasser vobs are motor tuning or a warped crank.