Orion NEWTONIAN ASTROGRAPH 9527 - Manual (Page 3)

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are M6. It is likely that only the center hole will be needed to
attach the rings to a dovetail plate for your mount or for your
guide scope assembly.
Balancing the 8" f/4.0 Newtonian Astrograph is achieved
by sliding the dovetail mounting plate (sold separately) for-
ward or backward within the mount’s dovetail saddle. You
can also move the telescope forward or backward within the
tube rings. The tube rings offer the most adjustment range.
Loosen the tube ring clamps slightly and slide the telescope
tube forward or backward as needed to reach optimum bal-
ance, then retighten the tube ring clamps. Rotating the tele-
scope to achieve a comfortable eyepiece or camera angle is
done in the same fashion. Simply loosen the tube ring clamps
just enough to allow the optical tube to rotate within the tube
rings. Retighten the tube ring clamps securely once you have
reached the desired eyepiece or camera orientation. Dual-Speed Crayford Focuser with Linear
Track Bearing
The 8" f/4.0 Newtonian Astrograph features a machined alu-
minum, 2" dual-speed Crayford-type focuser
(Figure 2) that
incorporates a linear track bearing design. The linear bear-
ing eliminates drawtube play and enables support of heavier
loads without slippage. If the drawtube does slip under the
weight of your imaging system or heavy visual accessories,
simply increase the drawtube tension by gently tightening the
drawtube tensioning thumbscrew as needed.
The smooth focus motion and fine-focus wheel allow preci-
sion adjustments for critical focusing of eyepieces and camer-
as. Once you have reached focus, you can lock the drawtube
in place by tightening the focus lock thumbscrew.
The focuser drawtube has 50mm of travel and English and
metric hash marks, which allow you to note the drawtube
position at the precise focus point so you can return to it when
you need to.
Figure 2. The dual-speed 2" Crayford-type linear bearing focuser
Accessory lock
thumbscrew
Focus lock thumbscrew
2" Collar
Accessory
lock
thumbscrew
10:1 Fine
focus wheel
Coarse
focus wheel
Coarse
focus wheel
Drawtube tensioning
thumbscrew
Brass
compression ring
Accessory lock
thumbscrew
1.25" Adapter