Now you know the other use of the template I used for installing the
aluminum spacer tabs. With its radiating lines notating its center,
the template is now being used as a centering alignment target to aid
in collimating the 6" f/10 "GJD", which shows the task completed in
the image above. But, below I will explain the steps.
The
general rule in collimating an achromatic refractor is to first
collimation the focuser to the objective, and then the objective to
the focuser. In applying the rule, the template was first put in
placed in front of the mounted objective, then the laser collimator
was inserted directly into the focuser's visual back, secured and
switched on (ATTENTION!!! --- PLEASE
DO NOT LOOK DIRECTLY AT THE LASER,OR POINT IT AT YOUR'S AND ANYONE
ELSE'S EYES). The focuser was then methodically
adjusted using the three (3) sets of collimation bolts (two bolts per
set --- one bolt pushes-pulls, while the other locks down the
position). To facilitate the alignment process, with all three sets of
bolts loosened, I would grab holder and pull back on the collimating
ring that holds the GSO 2" Dual-Speed Crawford focuser with just
enough force to keep it from flopping around. Then, I would begin
turning the "push-pull" bolts for each of the three (3) sets to get
the laser beam pointed directly at the center of the template. Once
the laser beam is center on the target while still pulling back on the
focuser, I would then evenly tighten down the locking bolt for each of
the three (3) sets, thereby establishing accurate alignment
collimation of the focuser to the objective.
With the focuser
end done, the next step was to collimate the objective to the focuser.
This was performed with the laser collimator still in the focuser with
the beam pointed at the center of the template in front of the
objective. Held firm and pulling back on the front lens cell, I then
loosened the locking bolts and meticulously adjust the push-pull bolts
of each of the three (3) sets to cause the reflection of the laser
beam off the back of the objective to travel back down the OTA to the
focuser end; whereby I aimed the laser beam at the center hole of the
45-degree display on the laser collimator itself, which actually is
where the laser beam originated. Once the beam was centered, I
tightened down the locking bolts on the objective's front lens cell to
preserve the collimation alignment settings.
Collimation of the
"GJD" is now done! Once the dew shield is installed, the construction
of the OTA will be complete! |
|
