Re: [ATM] Use of bearings in (static) mirror cells

["Don Clement" <clement.focuser@verizon.net>]

Flexures do have friction. The advantage of flexure over sliding or rolling
bearings is the absence of stiction with a flexure. Stiction is where there
is higher friction when moving from a static state than when changing
velocity of a moving state. Stiction is the reason why tapping is sometimes
used to nudge sticky static mechanisms.  Before taut band meter movement on
mechanical analog indicators there were sticky meters. In fact, some
aircraft instrument panels have a vibrating module to free the  sticky panel
meters. John Strong mentions very low friction quartz fibers in " Procedures
in experimental physics"  The most precision metrology positioners use
stiction free flexure bearings.



Don Clement

Running Springs, California

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