Dean
    A few of my thoughts, experiences and questions. I have used cross
flexures in the VBB style sensor described by Sean Thomas. I experienced oil
canning with parallel 0.001" steel stock but not as much with 0.005 phosphor
bronze. I think what I was experiencing was the fact that the two parallel
shims were not in the absolutely same plane. I think the idea of something
other than 90 degrees would work well. I haven't calculated the moment of
inertia of fine music wire vs flat stock but parallel music wires might
prevent this phenomenom.
   With regards to flexural steel properties, have you any  references or
input relating to steel relaxation vs time under stress? The VBB sensor uses
an ~ 0.018" strip bent in ~180 degrees for a vertical spring. I have needed
to adjust the zero for several months before the deflection/relaxation slows
down. Someone in an earlier message likened this to the slow relaxation of a
piano wire under stress. I think this would be a similar mechanism. I would
be interested in a possible relation between strain vs time at various
stress levels. How sensitive  might this be wrt different metals?
Regards
Barry




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