Originally Posted by
helispotter
what if those are reaching the limits of travel of the Nodamatic suspension system? Such limits must be reached eventually? What loads are transmitted between the parts once that is happening?
The nodal arms have up and down stops that limit the travel. In Post 127 just below the break in the lift link, you will see one of the up stops. Once the nodal arms hits those stops that result is directly transmitted to the airframe which you will feel in the aircraft. For example, if the minimum blade angle or autorotation RPM is not set properly, the nodal beams will bounce against the down stops and produce a noticeable "knock" in the cockpit with the collective full down. The common "fix" is to simply pull a bit of collective to pull the beams off the stops, however, the correct fix is to adjust the min blade angle or auto rpm.