This is my resign of Mirrcr Call. It ;s simple but it provides very
little adjustment. As I machine the ends of the tulle square and grind
the back or the mirrors to give even thickness a s not necessary. Also
the mirror is located on its front face. Mirrors differed in thickness
and each cell was machined to suit. A small amount of adjustment to
hold the mirror against the retaining washers on the side support pillars
is provided by The vinyl cads with the gruo screw behind them.
The end ring forms part of the cell and it and the top end ring are
machined from the same casting. The three pillars and wasners ;hat hold
and locate the mirror are machined from hard black nylon rod. The pillars
are machined out 'o suit each mirror. Adjustment for alignment is by
compressing the neoprene `0" nngs between the mirror holding elate and
the end ring. There is very little adjustment but I have round that
this was all that was necessary.
However with the mirror cell fixed in the tube. the positioning of the
focussung unit is very critical. Holes cannot be cut 5y trial and error
until right. I therefore made a modified cell for others to use who
do not have my facilities. With provision for variation in mirror thickness
and where it can be moved up the tube until the correct position is
found. However a separate end ring is required to give the telescope
a finished look.