play in main gear

[bgjames111]

Noticed today there is probably 3-5mm play, up and down in the main gear on my new extreme. The manual was terrible, mostly pics, and no text. I read the stratus manual and it briefly mentions shimming. I can't imagine shimming 3-5mm, seems like a lot.

I'm disappointed with MA for not including shims.

Am I missing something?

[kthane]

Something is missing if you can get a tail rotor shaft in there! 3~5mm is a huge gaping hole. Should be crown gear hub, shim, teflon ring, shim, then the auto hub, then shim, teflon ring and lower collar. Granted my fury is old as the hills, but they included extra shims with mine.

[bgjames111]

I swear they didn't include extra shims! I'll take it apart and double check, but I'm pretty darn sure I got it together right.

[DavidH]

Most of the time putting the constant drive tail hub together as specified in the instructions will have it a little too tight for my preferences, If you have 3-5mm vertical play as you say. Then you have assembled it wrong.

Here is a drawing of how it should go together.
http://www.ronlund.com/images/plans/xlse/main_shaft.jpg

Also pages 19 thru 22 here
http://www.rchelibase.com/xcell/extreme.pdf

My preferences is that there is 1mm, maybe 2mm of vertical movement between the crown gear and the main gear hub. That will give what I think is the smoothest operation of the unit. The crown gear hub is attached directly the main shaft. So there is no vertical play between the crown gear and the pinion. The main gear will move vertically on the clutch bell pinion. This is not a problem.

David

[bgjames111]

Thanks David, I had one of the shims in the wrong place.

The heli makes a noise that I'm not sure is normal. Kind of a warble if you will. I've checked everything I can think of. The heli flies super tight, and smooth so I'm not sure what can be making this sound.

[kthane]

Check and see if you have up and down play in the clutch bell. The pinion is held with loctite to the inside race of the buttom bearing of the start shaft block. If this breaks loose, it'll make a very hi pitched squeaky gurgly kinda noise. If the noise gets better the more you fly it, it's probably the gears whistling til they break in, if it get worse, you got something going on.

[bgjames111]

Thanks, I'll check it.

[bgjames111]

no up or down play in the clutch bell, but I did discover that I didn't install the tail drive pinion right in the center of the crown gear. I fixed that, reset mesh and I hope that was maybe the issue.