Mirror Cell Modifications
Well, while the optics are off getting coated, the mirror cell has been
modified
a bit to work better.
First, the baffle tube was removed. It was mounted to the part of
the
cell that held the mirror and TILTED, so whenver the collimation was
adjusted,
the baffle moved and was no longer aligned properly. This would
be
remedied later. Next, the handles were removed, along with all
the
old bolts. The baffle tube base was squared up, and the top was
trimmed
to the new proper length as per the optical design.
Next, the baffle tube was modified so that it could be collimated, and
was
set up for "push-pull" bolt operation. Holes were cut in the 1/4"
aluminum
plate that backs the cell in preparation for three cooling fans.
Handles
were reinstalled near the edge of the cell.
The new focuser, a wonderful two-speed
unit from MoonLite
CF2-s (normally used on large refractors), arrived and
is also pictured below. It's anodized black, and the motion is
silky smooth. Fit and finish are first rate. The knob at
left is the coarse focus, and the knob at the right is the fine
focus. Ron Newman of MoonLite even made a custom base (seen best
in the two photos after these) that was thicker and larger than normal
to accomodate the location of the baffle tube. The larger plate
also reinforces and reduces flexure of the back plate of the cell,
making the whole assembly more stable. The focuser can be
collimated during final assembly of the telescope.
Next, the base was removed from the new focuser and bolted on the back
of
the cell. It was then removed so holes could be drilled to
remount
the baffle tube with the push-pull bolts.
Finally, both the baffle and the new focuser were mounted, and lots of
pictures
were taken of the entire assembly. Now, all it needs is the
mirror! The focuser has 4.5" of travel (!!!), so it sticks out a
long way when fully extended. The baffle tube limits inward
travel by a small amount, but this still leaves us with 4.0" of
travel. That's more than our old focuser, and much smoother!
