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hole of the bulls-eye screen and pretty
much disappears, except for some
red "spray" around the periphery of
the hole (Figure 5b). You can make
certain the laser dot is properly aimed
into the hole by slightly adjusting one
of the collimation knobs to bring the
laser dot out of the hole, then return
it by turning the collimation screw the
other way. Collimation of the optical
system is now complete! Go out and
enjoy the view! The alignment of the
mirrors should not need to be adjusted
again unless the telescope is handled
roughly. If you handle the telescope
gently during transport, then only slight
adjustments will need to be made to
the mirrors. Use the LPCS before each
observing session to check and make
adjustments to the mirrors as needed.
To preserve battery life, be sure to turn
the laser pointer OFF after each use.
4.2. Care and Maintenance of
your LPCS
The LPCS is manufactured of the
highest quality components. Great
care was taken to avoid any backlash
between components. If it is dropped
or handled roughly, the internal ball
bearings may become loose, and the
LPCS performance might be reduce
Avoid exposing the LPCS to water,
dust, heat, or prolonged periods of
direct sunlight.
appendix a: Marking the Primary Mirror
To achieve the best accuracy when collimating with the Orion LPCS, your
scope's primary mirror should be precisely center marked. If your mirror was
not center-marked at the factory, you can do it yourself with one of the supplied
collimation targets. This will not affect the telescope's performance at all. To
accurately locate and mark the mirror's center point, you must first make a paper
template. First, remove the primary mirror from your telescope. If you are unsure
how to do this, consult your telescope's instruction manual. If the primary mirror
is glued into its cell, it is not necessary to remove it from the cell. Handle the mir-
10
Figure 17. Adjusting the primary mirror
screws moves the laser dot on the viewing
screen.
Figure 18. The laser dot is projected
on the viewing screen. When perfectly
collimated the laser dot is coincident with
the central hole.
a.
b.
d.
e.
Figure 19. To mark the center of an unmarked primary mirror, a) trace the outline of the
mirror on a piece of paper and carefully cut out the circle, b) fold the circle in half, and c)
then in half again, d) cut the tip off the paper wedge, e) place the template on the mirror
surface and carefully register its edge, f) stick the ring label to the mirror surface through
the hole in the template. Then remove the paper template.
ror by its edges only, and be careful not to touch the surface with your fingers.
Get a clean sheet of paper that is big enough to cover the mirror's entire sur-
face. For large-diameter mirrors, you may need to tape several sheets of paper
together. Lay the primary mirror on the paper and trace its outline with a pencil
(Figure 19a). Next, cut out the circle you have just traced with a pair of scissors.
Fold the paper circle into quarters by folding the circle precisely in half, and then
folding it in half again (Figure 19b and c). Now, cut about 1/4 inch off the tip
of the paper wedge you have created (Figure 19d). Unfold the paper, and you
will find that you have a paper template of your mirror with a hole at the center.
Make sure the template is still clean; place the paper template over the surface
of the primary mirror. Carefully register the template edge with the edge of the
mirror (Figure 19e). Now, take one of the supplied adhesive collimation targets
and affix it to the center of the mirror's surface through the hole of the paper
template (Figure 19f).
The center of the primary mirror is now marked, as in Figure 13, and you can
reinstall the primary mirror in the telescope. Note: For mirror cells that use mirror
clips to secure the primary mirror in place, it is important not to overtighten the
mirror clips. For Orion reflector telescopes, tighten the mirror clip anchor screws
until just snug, and then back off each screw by 1/2 turn. Overtightened mirror
clips will put stress on the primary mirror's figure, and will introduce astigmatism
into the optical system as a result.
c.
f.
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