What Constitutes "Bent"?

[KeukaBlackBear]

I'm still new to this game and I need some calibration.

I'd like to do AVP with my Logo 10; however, I have a bit of vibration. Tearing down the heli, I find that the main rotorshaft is 'out' by perhaps 0.005". I'm guessing at this as I have a good straight edge, but no real way to measure gaps except by inserting paper. 'Regular' printer paper just fits in the gap between the main rotorshaft and the straightedge.

Is this enough out-of-straight to cause noticable vibration in an AP video cam?

Ah yes, my headspeed is 1440 rpm.

Thanks for your help,

Sandy

[EricTheRed]

I would think that anything that is not "true" would cause a vibration. Even a bad bearing would cause a vib. After my first main shaft went, i replaced it with the "hardened" version. At 1440 HS, you may amplify the vibration problem somewhat. Try a higher head speed and see if the vibration issue goes away.
-Eric

[trireme]

I would think that anything that is not "true" would cause a vibration. Even a bad bearing would cause a vib. After my first main shaft went, i replaced it with the "hardened" version. At 1440 HS, you may amplify the vibration problem somewhat. Try a higher head speed and see if the vibration issue goes away.
-Eric

Since vibration is so critical in AP, I would assume that any amount would be NG. Some people dont even use new shafts if they are slightly out. The main shaft is a very cheap part. I would swap it out, and if you dont notice any improvement, that you have a spare.

[KeukaBlackBear]

Hi Guys,

Thanks for your comments. ErictheRed, I agree that anything that isn't true is bad, but to a point. I was hoping someone could tell me if the cut-off for a main shaft runout is measured in increments of 0.001" or 0.0001".

I'm guessing it's the latter and if you can see light against a straight edge, the part in no good.

I did, in fact, buy both a std and hardened shaft to replace what I believe is a bad one, and you're right, trieme, they're inexpensive enough to do some testing. BTW the hardened shaft showed nothing on any rotation against my straight edge. Haven't checked the std shaft, yet.

Thanks again,

Sandy