HB2 Rotor head wobble

[Gizmo]

Has anyone had this before? It's the standard assembly and it just wobbles horribly.

The main shaft is not bent i can see that, it's the actual rotor head assembly that is of centre (if thats what it is).

The flybar and blades are properly balanced.

The main shaft holding pin is not bent.

Even without the blades on it does this.

From this photo you can see that the main shaft is true, even the bottom of the feathering shafts vertical counterpart shows its inline, but the top portion of it is not.

http://www.3dstyle.net/CB.HBCP2.unbal.jpg

How can i stop this? The shaft fits into the head nicley, with a little movement from side to side where the holding pin is, but this slight play is supposed to be there right?

Thanks for any help

[marktigere1]

Hi

Are you sure the main shaft is not bent further up itself?

Best way to check is to remove it and roll it along a piece of glass or very smooth worktop.

I had a similar thing on my Trex. Shaft looked true near the middle but there was a wobble on the head.

When I rolled the shaft on the kitchen worktop it was out. Not much but enough to caused a problem.

Also check feathering shaft in the same way.

Another thought, are the main shaft bearings okay with no play?

Cheers

Mark

[lbl25a]

Does this happen both on the ground and in the air?

My head is a sloppy fit on the shaft, maybe as a result of crashing? It wobbles on power up but as the blades begin to lift the wobble stops.

I am thinking of machining up a new alloy hub to take the existing plastic collective but haven't got round to that yet.

[Sesame]

If you check the shaft and still think its straight, what I would do is take the head off and just quickly run up the motor and see if there is any movement in the main gear, shaft or bearings.

probably not the best thing for the motor with very little load but a quick spin at low revs should be ok. enough to see if you have a prob there.