The clamp mechanism itself has three thumbscrews that push against three specially
designed flexure areas of a thin internal plastic sheath (figure 3.13). These flexure areas
are deigned to deform inwards to form ‘folds’ of plastic that grip the eyepiece by friction.
Figure 3.13 Inside the eyepiece clamp.
Top
: The plastic sheath that overlies the three thumbscrews has a
flexure fold over each screw with tiny plastic connections that are designed to break when the screw is
sufficiently inserted (CAD model is shown left, actual clamp is shown on the right).
Bottom Left
: Before the
connections break the flexure folds are flat against the inside of the clamp giving maximum clearance.
Bottom Right
: After the connections break there will always be some residual in-folding of the flexure giving
narrower clearance.
When this clamp is brand new (freshly printed) the flexure folds of the inner sheath will be
flush against the walls of the clamp (figure 3.12, bottom left) but with use these folds flex
inwards and the tiny connections of the folds in the sheath
are designed to break
to
allow maximum flexing to hold eyepieces of up to to 2.5 mm variation in diameter. Once
those tiny connections are broken the indented folds of the sheath will never return fully
flat against the clamp (figure 3.13, bottom right) –
this is normal for the design of the
clamp and is not a fault
.
OptArc AF51 Camera Page 39 of 99 User Guide v1.02
