vibration, tuning and performance
A TOP Lockheed helicopter engineer once told me that his main job was tracking down and eliminating EVERY vibration. Vibration severely limits performance, eating energy, and drastically shortens the life of the heli.
That's why I go to such pains to adjust the 80+% of these 5888s that are not
And because every individual 5888 blade and mechanical part is different, it is necessary to compensate with selected parts from dead helis, or new parts or to modify those parts, such as micro-bending or twisting the alu plates and filing the too-often thicker end of the plastic pieces that are sandwiched between the plates, etc.
And to try diff. blades, swapping the blades " 180° ", trying diff links, esp. the upper link [only use ONE!!], moving the link to the other side, finding which ball on the stabilizer bar is larger, BALANCING the stab. bar [often swapping or changing scress is enough], trying diff pinions, inverting the pinions ....
until everything is silky smooth, with NO resistance by hand and NO vibration in flight.
Try it ... you'll love it!