Result of bent main shaft during AP

So after my crash into the tree last week, I did the "roll the main shaft on the table" thing and thought it was ok, until I saw my first videos from flying. The first thing I noticed was blade tracking off by a lot. I figured it was because of new blades, I was able to get the tracking right on so I figured it was OK. Nope, as the video shows during autorotations it was terrible, so I took it apart and put a dial indicator on it in the lathe, the result is .004" TIR and lots of Jello.

http://www.youtube.com/watch?v=eomQHtfaWZ0

Nice video and demonstration.  Your video productions are getting better too.

Thanks, after being able to get the blade tracking right on with a bent main shaft just shows how complicated this stuff can be. I can just see a total newbie pulling out hair trying to figure out "what is wrong with this thing"!

Don't need me to tell y'all but "they" will say and I've found it also true that whenever the head takes a hit, even the smallest of hits you'll find the main shaft will also be bent ... Well I can't or shouldn't say it's a certainty but darn near to it !!! I'm at the point I don't even bother checking to see if the shaft is bent, I just assume it is and order a few new ones with the other crash replacements I need ... Meh, I replace them regardless of what maybe or might be, even better to have lots in inventory as your going to need em sooner or later

EDIT: Hey just a thought but you have the machinery to go into the shaft production yourself ... Whoops, forgot to mention the bearings often take damage also which can complicate any resulting vibration issue

I've found that the bearings will hold up better than the components they are mounted in.  I've had bearings that were fine, but it doesn't matter if the bearing's outer race is loose in whatever it is mounted into.  Sometimes a drop of thread locker on the bearing's outer race can help with that.