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View Full Version : Slight friction in one mixing arm


p28driver
12-05-2009, 12:26 AM
My 500esp kit arrived today! :banana I don't know who was more excited, me or my 2-yr old, who on seeing the box immediately said something that reasonably approximated 'helicopter', along with a clear "open, open!!' He was most upset when we put the parts back in the box and sent him to bed.:(

Anyway, I of course immediately jumped in and built up the head through the flybar. However, I noticed that one mixing arm has slightly more friction in its movement than the other. I don't even know if I would have noticed it had I not had the other one to compare to, but I think so. The only think I can think of that didn't go perfectly is that on one side (don't know which) the screw slid back through the bearing after I put a touch of loctite on the tip (I put the loctite on the tip after putting the screw into the bearing, intentionally trying to avoid getting any loctite inside).

I would have thought that any loctite in the bearing would freeze it up pretty solid. Does the amount of friction in the bearing depend at all on how far the screw is tightened? Should I be worried? Should I be ordering a new pair of bearings?

On a marginally related note, anyone else find a ridiculously small amount of blue loctite in their kit? I mean they actually would have had to try pretty hard to get such a small drop in the bottle!! :roll: First item on my shopping list...

superjoe83
12-05-2009, 09:26 AM
i found that one of mine was a little tighter than the other, i can still move it easily and it will move if i give the head a shake, so im going to run it as is, if yours is considerably tighter that the other one i would take it back apart and check the bearings and make sure all of the washers are in the right spot

p28driver
12-05-2009, 05:01 PM
I'm probably overly worried - it definitely flops back and forth quite freely. If I lift up the heavier side and let go it just takes a little longer for it to fall than the other side, and I can feel the difference when I move it my hand. It still feels smooth, no notchiness and not much drag, just enough different to notice. Could it just be a little more torque on the screw than the other side? I would have thought it wouldn't matter unless you tightened enough to start crushing the bearing.

Timmster
12-05-2009, 05:19 PM
If it falls on it's own with gravity you are definitely good to go. If you want to be a perfectionist, pull it apart and check the bearing itself make sure the inner race is actually moving and not seized and rotating around the screw. (a possibility) When I put those on I found it easier to slide the screw in, dip the end of the screw in some loctite and wipe off the excess with a paper towel or my finger then it goes on nice and smooth and no loctite squishes out into the bearing. Oh yeah, and make sure you didn't accidentally drop a washer!

p28driver
12-05-2009, 11:29 PM
Ok, thanks guys. I applied the loctite after putting the bolt through, but should have wiped it off more, and should have left my finger over the head to keep it from sliding out when I tipped it upside down! I don't really think it's a loctite issue, but I'll probably disassemble anyway just for kicks. No sense in giving up on perfection after the first day!

skyfrog
12-06-2009, 02:42 AM
I just built mine this weekend and found the same issue. The problem was the spacer between the two bearings in the arm was soft and crushed when I tightened it causing it to rest on the inner and outer part of the bearing. I bought some plastic mixing arms from the LHS and took the bearings and the spacer out of them and they were interchangable. I reassembled them into the ESP metal arm and it was smooth as butter.:thumbup:

p28driver
12-06-2009, 09:13 AM
The problem was the spacer between the two bearings in the arm was soft and crushed when I tightened it causing it to rest on the inner and outer part of the bearing. I bought some plastic mixing arms from the LHS and took the bearings and the spacer out of them and they were interchangable. I reassembled them into the ESP metal arm and it was smooth as butter

Now THAT makes sense. I'm stopping by the LHS today to pick up some other stuff, so I'll see if I can do the same. Wouldn't hurt to have an extra couple bearings around anyway, if that's not the problem.

Any suggestions on how to pop the bearings out without damaging them?

Maybe my "torque wrench" (aka fingers) needs a recalibration... :YeaBaby:

skyfrog
12-06-2009, 12:37 PM
I was worried that the spacer crushed into the bearing so I reloaced them with the ones in that came with the palstic arms. They are the same. Since I was replacing them I didnt use too much caution taking them out. I used my allen in the center of the bearing and pushed them out tapping the back of the allen driver on the table. Also, be sure to use the shim washers that come with the plastic arms too. you will see that on the ones that you have already used on the original install will be concaved from tightneing. These are the small shinny washers that go on each outside surface of the bearings. This was the only issue I had with the build. They just seemed waayyyy soft. The ones I replaced then with were more stout...even by looking at them they were not as (tin-like).

PyroM!KE
12-06-2009, 02:12 PM
Is this problem on the esp too?

superjoe83
12-06-2009, 02:18 PM
it was on mine

p28driver
12-06-2009, 05:23 PM
Mine's an ESP also. I don't know yet if my problem is related. My LHS didn't have the part, so I'll have to order. I probably won't disassemble and check until I get the replacement. I'll post when I figure it out.

skyfrog
12-06-2009, 10:06 PM
Yes, mine is an ESP. New frame version too!! Here is the part #. Its only $9.99. Not disassembling is a good idea. If you do it will be worse the 2nd time around.

H50024 SF Mixing Arm T-REX 500

Timmster
12-07-2009, 06:31 PM
I think the moral of the story here is don't over tighten the mixing arm!?! let the threadlock do it's thing! :thumbup: As long as you have a fair amount on there you do not need to apply excess pressure to lock it down.

skyfrog
12-07-2009, 11:25 PM
That is good advise too!! It just seemed like the spacer was much softer and of poor material vs the older version that came with the plastic arm. I just built a 600n right before this one and you do have to be a bit more carefull to not crush stuff on the smaller birds...:thumbup: