Duho...stupid tail wag

[maddog57]

I owe it all to Bullitt. I'm a happy heli boy.

Chris

[tony521]

I just noticed on mine, if i pull on the tail grips, there is a lot of play along the hub, even though the grip bolts are tight, i don't have any wag, but i was wondering if this is ok.

[bullitt]

Tony,what seems like excessive tail blade grip end play on the hub is normal on the atom.

Maddog, as I recall you said you bought the tailgrips and hub as a factory assembly.
My guess is one of the thrustbearing races was installed backwards so as the balls were running on the flatside of the race instead of the side with the radius cut for the balls to ride in.
just a hunch

[tony521]

ok , thank you very much, had me a little worried, but all in all, i don't have any wag.

[geckgo]

I ordered some new grips and anew hub for my B450 after reading this. It's one of the few pieces I have not ripped apart on it.

[maddog57]

I just finished taking the bad tail grip/hub assy. apart and think I know why this assy. caused my wag. I remember reading in a thread here, that the thrust brg, races have different I.D.s and I think the larger one goes on the inside of the grip and the smaller one goes to the outside. They were in backwards which will cause tail wag, yes?

Bullitt yes, this was a factory assy. You were close on your guess about the thrust races man.

Think I'll assemble it the right way and put it on to see if it still wags. If it still wags, I'll just toss it as I don't find anything else wrong with it... and after all the headache and heartache I've gone thru, it's not worth any more.

I thank all the guys who tried to help me last year. I learned something from all the helpful posts. I especially thank Bullitt for curing the problem!

Chris

[Jeff_Barrett]

Check the thrust races as frequently they come installed wrong from the factory, this will cause wag.

And yes, the in/out play of the grips on the hub is normal ... the Warp 360 main rotor hub was designed around this same principal. Centrifugal force pulls the grips out against the spindle bolts and into their proper position.

I prefer this design as I've seen others where everything has to be just right or the grips won't rotate freely due to side loading on the radial bearings.

[maddog57]

I don't understand the reasoning for the thrust races having different I.D.s. I would think that you'd want both races to be the smaller dia. I think the main blade grip thrust brgs, are the same way.

Chris

[Jeff_Barrett]

I think the main purpose is so that there's less chance of the race dragging on the hub shaft. Most thrust bearings have a smaller ID on one side.

[maddog57]

That makes sense, thanks Jeff.

Chris

[bullitt]

Originally Posted by maddog57

I just finished taking the bad tail grip/hub assy. apart and think I know why this assy. caused my wag. I remember reading in a thread here, that the thrust brg, races have different I.D.s and I think the larger one goes on the inside of the grip and the smaller one goes to the outside. They were in backwards which will cause tail wag, yes?

Bullitt yes, this was a factory assy. You were close on your guess about the thrust races man.

Think I'll assemble it the right way and put it on to see if it still wags. If it still wags, I'll just toss it as I don't find anything else wrong with it... and after all the headache and heartache I've gone thru, it's not worth any more.

I thank all the guys who tried to help me last year. I learned something from all the helpful posts. I especially thank Bullitt for curing the problem!

Chris

I knew about different race id's on main shaft thrust bearings but not on tails.
Nice catch Chris.That assembly should work fine now.