© Opticstar Ltd / Ascension 2007-2014
18
APPENDIX C: The Focuser
Focuser Adjustment
The Ascension comes with a 1:10 dual-speed focuser
that has been adjusted at the factory. In certain cases it
may be necessary to regulate the tension to improve
performance by adjusting the two silver thumb-screws
below the focuser. This may be required if the focuser
was adjusted at room temperature and then used in sub-
zero temperatures.
Also as the focuser is worked-in over time surfaces smoothen out and the
focuser may need slight re-adjusting. When done for the first time this
procedure requires patience and time.
We recommend only adjusting the focuser beyond simply re-adjusting the
two silver thumb-screws, as outlined below, if there was a real need. The
focuser has been designed to be fine-tuned
externally
by the user.
It is also possible to re-adjust the
internal
clutch of the focuser
mechanism to regulate the tension
on the focuser drawtube for which
the clutch will need to be removed
for the adjustment to take place.
Please keep in mind that this is a
rather
difficult
procedure
to
perform without experience and
the right set of tools.
To set the tension on the focuser drawtube follow the instructions below:
1.
Remove all accessories from the telescope drawtube
2.
Tilt the telescope to say 60 degrees and pointing to the sky
3.
Loosen thumbscrew
A
4.
Loosen thumbscrew
B
5.
Tighten/adjust thumbscrew
B
in very small increments till you obtain
the preferred focus tension
6.
Attach a heavy accessory to the focuser like a 2-inch diagonal and
eyepiece.
7.
Go to step
4
and repeat the process until the tension is right.
8.
Lightly tighten thumbscrew
A
until it comes in contact with the
