One Way Bearing On My Align 500

[Derek]

Marius's recent post got me thinking about my 500. Keep in mind that my helicopter is a flybarred helicopter with the Align GP780 Heading Hold gyro. The swashplate is level and the blade pitch is set at +/- 10 degrees. I did take the head completely apart and each bearing is in good working order and it free and clean of any debris. I did add oil and grease when I put it back together. The helicopter will not hold a steady hover. Without correction, it wants to roll to the right. It's not leaning to the right, it wants to roll to the right slowly. Worse yet, last time I flipped it inverted and tried to punch out with negative collective, the tail whipped around and I nearly lost it.

So, like I said, Marius's recent post about the OWB got me thinking that maybe the OWB on my 500 is going bad or is slipping. So, I just removed the main gear set from the helicopter. I grabbed the main gear and tried to turn the autorotation gear. It will turn in it's usual direction with ease and when I tried to turn it the other direction, I couldn't turn it with my hands...using a great deal of force. Maybe I'm wrong but I would think if the OWB was slipping, I should be able to turn it in the direction that it normally wouldn't turn.

Any thoughts?

[Derek]

I went ahead and ordered a brand new one way bearing for my 500. I can't confirm that it "needs" it but a NEW part never hurt anything.

[pvolcko]

Owb is fine from the sounds of it. If it were slipping it wouldn't cause a roll. Sounds like a mechanical leveling / setup issue.

[Derek]

Owb is fine from the sounds of it. If it were slipping it wouldn't cause a roll. Sounds like a mechanical leveling / setup issue.

Thanks for commenting, Paul! Aside from the OWB, I just really don't know what has gone wrong with my precious 500 helicopter. I'll just leave it on the shelf for now. Perhaps we'll get another "rainy day" on one of my days off and maybe I'll sit down with it again.

Bummer!

[pvolcko]

It's a flybar, does dialing in some left roll trim not fix the issue with the rolling?

As for inverted...

Are you sure the swash is level throughout the travel of the collective? Almost sounds like it is picking up some tilt as you get away from zero collective.

[Derek]

With the helicopter on the bench, I can click on the left trim switch and I can see the swash moving to the left. Ok, recenter the trim switch and try to hover. It wants to roll to the right....begin clicking the left trim and, believe it or not, it still rolls to the right.

As for inverted, yep, I'm sure the swash is level throughout the travel of the collective. The rotor head that's on the 500 is the upgraded aluminum head. I still have the stock head with the plastic blade grips. I'm thinking that I'm going to try going back to the stock head and see what happens. If the helicopter will fly normally with the stock head, then I'll know that "something" is wrong with the upgraded head.

[Lee]

When my OWB went in my old 500, i could hear the fluctuating RPM.
I could hold the Main gear and turn the blades the wrong way by hand.
It didn't affect any handling though.
How is the longitudinal CG?

[Derek]

How is the longitudinal CG?

It seems to be "right on". I've not changed any component placement and the helicopter use to fly very well. This problem with the 500 just "showed up". Like I mentioned above, I'll put the stock head back onto the 500. Then level the swash, set the blade pitch and we'll give it a go. If the helicopter reacts the same, then the issue isn't with the head. If the helicopter reacts as it should, then the issue is with the upgraded CNC head.