ORION TELESCOPES & BINOCULARS StarBlast AutoTracker 10140, Instruction Manual

6

Telescope Maintenance

While your StarBlast telescope requires little maintenance, 
there are a few things to remember that will ensure your tele-
scope performs at its best.

care and cleaning of the Optics

In general, your telescope’s mirrors will only need to be cleaned 
very infrequently, if ever. Covering the front opening of the tele-
scope with the dust cover when it is not in use will prevent dust 
from accumulating on the mirrors. Keeping the dust cap on the 
focuser’s 1.25" opening is also a good idea. Improper cleaning 
can scratch the mirror coatings, so the fewer times you have 
to clean the mirrors, the better. A little dust or small specks of 
paint from the scope’s interior have virtually no effect on the 
visual or imaging performance of the telescope. So avoid the 
urge to clean the optics unless it is absolutely necessary!
To clean the primary mirror, carefully remove the mirror cell 
from the telescope. To do this, you must remove the screws that 
attach the mirror cell to the steel tube. These screws are located 
on the outer edge of the mirror cell. Then pull the cell away from 
the tube. Be careful not to touch the aluminized surface of the 
mirror with your fingers. Set the mirror on a clean, soft towel.
Fill a clean sink, free of abrasive cleanser, with room-temper-
ature water, a few drops of liquid dishwashing detergent, and 
if possible, a cap-full of rubbing alcohol. Submerge the mirror 
(aluminized face up) in the water and let it soak for several 
minutes (or hours if it is a very dirty mirror). Wipe the mirror 
underwater with clean cotton balls, using extremely light pres-
sure and stroking in straight lines across the surface. Use one 
ball for each wipe across the mirror. Then rinse the mirror 
under a stream of lukewarm water. Any particles on the sur-
face can be swabbed gently with a series of clean cotton balls, 
each used just one time.
Dry the mirror in a stream of air (a “blower bulb” works great), 
or remove any stray drops of water with the corner of a paper 
towel. Dry the bottom and the edges with a towel (not the mir-
ror surface!). Leave the entire assembly in a warm area until it 
is completely dry. Then reinstall the mirror cell in the telescope 
optical tube with the screws.
To minimize the need to clean your telescope, replace all lens 
covers once you have finished using it. This will prevent con-
taminants from entering the optical tube.

collimation

Collimation is the process of adjusting the telescope’s mir-
rors so they are aligned with one another. Your telescope’s 
optics were aligned at the factory, and should not need much 
adjustment unless the telescope was jarred while in transit. 
Accurate mirror alignment is important to ensure the peak per-
formance of your telescope, so it should be checked regularly. 
Collimation is a relatively easy process and can be done in 
daylight or darkness.
To check collimation, remove the eyepiece and look down the 
focuser drawtube. You should see the secondary mirror cen-
tered in the drawtube, as well as the reflection of the primary 
mirror centered in the secondary mirror, and the reflection of 
the secondary mirror (and your eye) centered in the reflection 

of the primary mirror, as in 

Figure 5a. If anything is off-center, 

proceed with the following collimating procedure.

The collimation cap

Your StarBlast comes with a “quick collimation cap”. This is a 
simple cap that fits on the focuser drawtube like a dust cap, 
but has a tiny hole in the center and a reflective inner surface. 
The collimation cap helps center your eye over the focuser 
drawtube so that aligning the optical components is easier to 
achieve. The reflective surface provides a distinct visual refer-
ence that is helpful in centering the mirror reflections

. Figures 

5b through 5c assume that you have the collimation cap in 
place.

The Primary Mirror center Mark

You’ll notice that the primary mirror of the StarBlast has a tiny 
ring (sticker) marking its center. This “center mark” allows you 
to achieve a very precise collimation; you don’t have to guess 
where the exact center of the mirror is.

Figure 5. 

Collimating the optics. 

(a) 

When the mirrors are 

properly aligned, the view down the focuser drawtube should 

look like this. 

(b) 

Here, the secondary mirror is centered 

under the focuser, but it needs to be adjusted (tilted) so that 

the entire primary mirror is visible. 

(c) 

When the mirror is 

correctly aligned, the center “dot” of the collimation cap will 

be centered.

a.

b.

c.