I am sorry to hear of your distress @Mark Mickels but I think i speak for everyone when I say that we have all been there before. Usually when i have vibes i go through a series of eliminations.

I first start by removing the head and tail assembly leaving only the main shaft and tail shaft protruding.

Clamp the model down and spool it up FAST v. Look at your vibe analyzer if you have one or place your hand on the boom.
Is the vibration there? If it is separate the tail assembly from the body - spool again. Check for the vibes once more by holding the body. If no vibes its probably your torque tube.

If at this point you do not have any vibes, put your boom back on.

Spool the helicopter again. Take hold of a screwdriver, position it perpendicular to the tail shaft and lightly touch the end with the screwdriver while it is spinning flat chat (be carefull). If you hear a ticking noise you know your tail shaft is slightly bend or the bearings are possibly damaged. Do the same for the main shaft again with no head or links attached. It should feel as smooth as butter with very light pressure.

If you have vibes and you do not have a vibe anlalyser, watch the swash plate when you spool. If you have vibes the swash will usually tilt and lean to the side after 10 seconds or so. At this point you have either found the fault or it is to do with the head and tail assembly.

First assemble the rotor hub onto the tail and attach the tail blades. Make sure the model is clamped firmly down. Spool the heli once more. Watch the swash plate - if it has vibes it will tilt or behave erratically.

If the vibes are present at this point disassemble the rotor hub and check that the assembly is correct. Check every washer, bearing etc because something would be throwing it out of center if there are vibes -

If no vibes then move on to the head and do the same. Be VERY CAREFULL Now as it will have main blades on it. Usually I never have to do this last part because if everything else is ok it must be in the head assembly (IE i have put an extra spacer on the feather shaft during the head assembly or something else silly).

This method has helped me eliminate vibes in every case so far.

Also the above is assuming that all your blades are balanced and not damaged.

Hope this helps,.

 

Good luck and keep us informed. Vibes can be the most frustrating element to track down at times.

 

That is simply divine! Now there is an upside to this. A) the mysterious vibes which can elude us always have a logical conclusion. By keeping cool and using a process of elimination you can break it down B) You now have many spares C) Each type of model has its own quirk. You have discovered a major one for the torque tube. Quite simply a bent boom will cause torque tube vibrations! Well done!

 

Vibrations have caused even the most experienced heli mechanic to their knees at one time or another. Always use the process of elimination on any new model you acquire.. Great work!