BenMer

Just a simple question. I have a CF inner and outer shaft and the old bird has been flying really well (CX\2), But last night her shafts started to 'wobble' and got progressively worse. I did all the usual checks and everything is fine. BTW, NO crash involved!! The bird is over a year old and I was wondering, could worn out bearings be causing this unknown wobble? The bearings are the only thing that hasn't been replaced! Actually, I never had to replace the servos either. Could it be the bearings, or something else underlying that I'm missing? Thanks!!

Mack66

Well something is out of balance, that's for sure. Not sure what you mean by the "usual" checks, but whatever you didn't check is likely the problem (haha?). You may be right, since too much play will also present itself in any rotating machinery as vibration.

Sometimes you can get a clue by studying the heads while running up the heli while holding it in your hand. Let it spin slowly and see if you can tell what is wobbling off-center. You know it could be something as simple as loosened upper head set screw that allows the head to slip up slightly from the upper bearing, allowing the bearing to float and wobble.

You would think it would be related to vibration induced loosened screws and fasteners or something like that or like you said worn bearings.

If it were me and I was sure the shafts are true, I'd do a general tear down and inspect everything. That being the case I'd have new bearings in hand before doing the tear down and replace them regardless. The upper inner shaft bearing could be the culprit I suppose.

Since you've obviously done this before it should be no biggie for you to do the tear down.

Let us know what the cause is when you find it.

Mack

BenMer

Hi Mack, and thanks for the reply. I removed the CF outer shaft and replaced with a new factory shaft, thinking that maybe the CF did something crazy. However, the problem remains. As a matter-of-fact, the factory wobbles worse than the CF one did. The problem seems, as far as I can tell, centered around the outer shaft. I tried holding her and it seems that the faster the spin the worse the wobble until it gets going so fast you can't really tell. Normally, I can fix a wobble, but this one has me baffled! So, I guess I'll run down to my LHS and pick a complete set of bearings, including the one for the center shaft. I'll let you know how it goes. Again, thanks!!!

JPEE

Hello,


I am with MACK on this but I have a plan for you that wont cost you a dime.

1.a Take out the battery and stick a pencile up throgh BOTH gears gently. Then try and turn the top blades and see if they are "locked" down to the bottom drive gear. Do the same with the lower blades.

1. Take off the flybar and spin up the heli and check for vibrations.

2. Take off the top blades """"""""""""""""""""""""""""""""""""""""""""

3. Take off the lower blades"""""""""""""""""""""""""""""""""""""""""""

4. Check the screw on the blade holder rotor posts, if they have come loose then the blades are tweeked by the swashplate.

Good luck JPEE

BenMer

Thank you both for your replies. However, the problem is now fixed. I took one of the old bearings down to the LHS and when the 'mechanic' looked at it, his first reaction was that the bearing is full of oily dirt. What I did about a month ago was put a drop of 3 in 1 oil into each bearing...big mistake. When dirt got into the bearing it couldn't fall out again because it adhered to the oil and eventually 'chewed' the insides to bits. Okay, that's being a little melodramatic, but it did ruin them. So, to make a long story short, he graciously sold me a new set of bearings, I installed them and now the Old Bird is singing happily again!! Not me, the helicopter Again, thank-you for the replies, it was much appreicated!!!

JPEE

Ben,

I would have never believed that if you had not written it. I dont use oil on my bearings, I use grease! I bought a Rc device called...."the greaser" and it is made for RC toys and will force grease in any bearings. I have greased all of the my helis and my plane motor bearings as well. If the grease collects dirt it will stay on the outside.

JPEE

BenMer

Hi JPEE! Greasing the bearings makes alot more sense than trying to use oil because, as you said, if it does collect dirt it'll stay on the outside. I just wish I would have realized that before hand!! Oh well, 'live and learn,' huh? One things for sure, I won't make that mistake again. BTW, where can you get one of those 'greaser' things? That is, without a doubt, the more sensible way to go! Thanks for the tip!!

Mack66

Hey JPEE, yes let us all know where you got that bearing grease packer. It's a typical device used in automotive applications so I guess I shouldn't be surprised if someone made one for tiny bearings. To me it sounds like something clubs should own for their members.

Mack

JPEE

MACK,

This first link tells you all about it. The second link it to Petes website and it on the left top side of the front page.

http://homepage.ntlworld.com/kevin.maxfield/greaser.htm

http://peteshobbies.com/

Let me know your thoughts

JPEE

J-MICHAEL

Ben ~

I'am glad ya found the problem with the wobble... Good to also see the CF shafts are working out good ! Now you have the outer CF...?! [8D] Sweet....



I WANT ONE....!

Mack66

This is great. Thanks, JPEE.

Mack

BenMer

Thanks JPEE!! I am also interested in that 'Greaser' and when I went to his site I noticed that it hasn't been updated since December 2006, so I e-mailed him just to make sure that it is still available. If it is, he'll be getting my $39.95!! Again, thanks for the link!!

JPEE

Ben,
I am told that old Pete makes them. I spoke with his wife and they are a mom and pop store kinda out of the house.

But they are carried for the same price at Helipoz posted below for you


http://www.heliproz.com/searchprods.asp


JPEE

BenMer

Thanks JPEE! I followed your link and, sure enough, it was there! Now, my only problem is I have to wait until the wife gets home from shopping to get my credit card back!![] Again, thanks for all the help and info and I know more than just I appreicate it!!

JPEE

Ben,


When I ordered from Pete he included a tube of grease. If you buy from Heliproz make sure they include the grease too!


My pleasure to help, isn't that why we here to help RC brothers............


JPEE