Warped Main Gear

[Tooly]

I've just started assembling my ECO8, using the autorotaion wheel and stock ECO motor.

One problem i have noticed is that the main gear appears warped after bolting to the autorotation hub, and has a definite wobble when the mainshaft is spinning! This results in some binding and stickiness when the tailrotor gear is meshing. I've never flown a heli before, but i am sure this is bad karma.

Has this happened with anyone else's maingear? I have tried tightening the bolts to the autorotation hub evenly: less/ more.. still wobbles. Also tried another main gear. The gear appears to remain flat until you bolt the hub to it...

Am i being paranoid, ie; should i leave it?or is there a better way?

Cheers,

Tooli

[Mike Sayer]

My main gear wobbles, but it doesn't seem to be a problem. I can adjust the gear meshing so that there is no binding, but there is still plenty of tooth engaged even where it is loosest.

regards

Mike

[Ripstop]

Tooly:

You're right, the problem is with the hub. As the mounting screws tap into the plastic hub, the plastic around the holes expands, (it simply has no where else to go.) The result is a warped hub. The solution is simple: drill out the holes to accomodate the screw diameter, then mount the hub to the gear with fibrelock nuts. (I plan on installing mine this way). Of course, you'll have to use longer screws for this.

Good luck.

[JOHNNOBLE]

DEAR TOOLY

I too noticed a slight run out on my main gear when i was building my heli,how ever i have`nt got the auto unit on yet(on order).
If your worried about it, what i would sugest is you take it off and start again,but when you are tightening up the screws,do them in a sequence;ie,tighten one up,then do the other opposite to it.You could also try boiling the gear in a pan of water for 30 minutes to take out the stress`s.


[This message has been edited by JOHNNOBLE (edited 04-09-2000).]

[Tooly]

Thanks folks...

Mike was right. The right gear meshing is important! I have the meshing quite loose at the moment, and it doesn't bind now(u can see the eccentricity from the bottom while the gears are turning). But the wobble still bugs me and i'll try the other solutions a bit later.

Happy flying!