Back around the very early 90's the Kyosho Concept 30/60 and the Kalt spacebaron/enforcer 30 had independent teetering head blade grips, however now we use the isometric rubber dampeners to create this effect withe a solid feathering spindle. During this era 3d was not in existance but for rare instances,, also lead lag of the blades was never limited, this lead to a condition of a main blade boom strike, which either sheered off the boom in flight or caused enough damage that ended in a crash anyways. the result was the schoonard helicopter xcell custom design of a solid feathering spindle dampener system. All manufacturers have followed suit ever since.

if any maker potentionally has one available would be Vario.