Mixer Arm bearings

[scottward]

Hi Guys,

Just wondering, those little bearings in the lower and upper mixing arms, they'd be getting a pretty good workout wouldn't they?

I doubt any maintenance is really required on them (e.g. oiling), better to just replace them when required?

But, how to know when required?

I'm thinking that the best way to check these little bearings would be to remove the mixer arm from the heli, and put a firm fitting shaft of some sort into the bearing, then give the bearings a tilt on the shaft to see if there is any play. If there is play, they need replacement.

The reason I ask is that last year my heli starting wobbling a bit, intermittenly.

I put new mixer arms on last year (platic to metal) and the problem went away.

Just recently the same issue has cropped up again, and although nothing else has changed, no crashes etc etc, I'm suspecting that perhaps it's these little mixer arm bearings???

Also, I recall some discussions about gluing the outside of the bearings into the mixer arms (perhaps only relevant to plastic)?

Thoughts?

Scott.

[scottward]

Any takers?

[B335]

You could check for play in the mixer arms by just manipulating them with your fingers. These should be on your pre-flight checks anyway (check all items for slop).

I'm on mixer arms that have been on there 2yrs+ with no play.

[scottward]

There should be absolutely no play whatsoever correct?

If there was play here, this could cause in flight wobbles?

Thanks for the help.
Scott.

[B335]

Correct, no slop/play on any parts. Tracking would be one issue, yes.

[scottward]

Cheers B335, I will check it out......