vibration

[gamernathan]

i am using jr's GSR 260 for a camera ship with NHP 800mm mains.
with out the camara mount on there is no vibration smooth as glass
however with the 10lb or so mount on the machine has a low freacency
vibration that take a couple seconds to set in and gets very violent very fast the hole machine starts to shutter. any help would be much apreciated, main shaft bent, bad bearing block ect. head speed was 1500
and then reduced to 1260 with the same result

[miami6]

i would start one piece at a time to log where the problem was at

main shaft , spindle, bearing blocks, engine, clutch, fan, tail shaft , blades , paddles,
boom supports, etc check every screw and so on
one item at a time

[gamernathan]

ok thanks, i have pulled the main shaft and spindle and will have them dial indicated, also the top bearing block on the main shaft feels bad and will replace. will keep my findings posted

[kaptkaos]

dont bother dial indicating the shaft, pitch it and replace it.
if you said the heli is fine without the mount, then i would look at the way you secure your mount, and your CG. The mount has to hang really loose, I mean, really loose! They all need the same tension and slack, have even corner weight.