freck

I have fitted a pair of nhp razor pro 515 blades to my swift, the head and blades are balanced fine but i am getting the dreaded chicken shake on spool down only it is fine when spooling up, the mod for the feathering spindle has been done so that is ok, i find that if i tighten the blades up pretty tight in there blade grips it is a lot better but if i slacken them of so they just stay straight without dropping it shakes quit bad on spool down, any ideas greatly welcome.
Freck.

mrasmm

this might not be of much help, but to me it sounds like when you have the heli sitting there the blades are pretty straight... for some reason when you spool up and the blades find their appropriate lead-lag positions the positions are not in balance. I don't know exactly what to balance to correct the lead-lag positions... but maybe that will give you a place to start if you didn't already know that... If you did, then it's probably not much help at all =(

freck

thanks mrasmm,
have had a good look at things the only way to stop the shake is to tighten the blades down hard in the blade holders , then it hardly shakes at all.
Freck.

mrasmm

a couple of things you might check are to make sure that the flybar paddles are level (parallel with the head assembly, they shouldn't have any pitch in them), that the flybar is centered. That the blades balance. If there are any weights on the fly bar, that they are at the same distance from the head. Maybe check to see that your main bearings and swash are properly lubed, and that there is not excess play in the head you have somewhere. Sounds like you have already given it the once over. If you can't find out what is causing it then I would just do what you are doing and clamp the blades down extra, even though normally that is not what you want to do.

and btw you're welcome =)

freck

yes i might just have to put up with it, i have about checked everthink possible but i wont give up just yet, i am of to fly it in a couple of hours so i will see how it goes.