Congratulations on your purchase of a quality Orion 2" dual- speed Crayford focuser. This focuser is intended for use with the Orion
Crayford focusers generally perform better than
The strong machined aluminum construction supports heavy 2" eyepieces as well as heavy camera bodies. The smooth focus motion and fi
Installation
This focuser was designed to be a
1.Locate the three screws holding the existing focuser onto the tube wall. In the case of the larger 120mm refractors, locate the screws that hold the focuser to the optical tube adapter collar.
2.Remove these three screws, making sure to hold onto the focuser itself so it does not fall when the last screw is removed. Do not lose the screws as they will be required to install the new focuser.
3.Remove the 2" focuser from the tube.
4.Place the 2"
5.Install the three screw, and tighten the screws fi rmly.
Usage
Using the 2"
The large focus lock thumbscrew near the focusing shaft (see Figure 1) locks the drawtube into position once focus has been achieved. This is especially useful when using a camera or heavy eyepiece in the focuser. Be sure this thumbscrew is loosened when focusing. The socket head set screws above the focus lock thumbscrew (see Figure 1) adjusts drawtube focusing tension. If a heavy eyepiece
Eyepiece thumbscrews
Focus wheel
Fine focus wheel
Focus lock knob
Drawtube tension adustment screws
Focus wheel
1.25" Eyepiece adapter
Figure 1. The Orion 2”
causes the drawtube to move inward by itself (drawtube tension too loose), or the focus wheels are diffi cult to turn (drawtube tension too tight), then you will want to adjust these set screw. This requires the included hex keys. Slightly loosen the center screw, then slightly tighten the outer screws equally. Test for tension and repeat if necessary (or reverse the procedure if the tension is too tight).
Fine Focus
The focuser features dual speed adjustment with the fi ne focus wheel. This small black wheel located on the side of the right hand focus wheel allows precise focus adjustment at a ratio of 11:1, meaning one turn of the focus wheel equals eleven turns of the fi ne focus wheel. Use the focus wheels to achieve rough focus on your target object, then use the fi ne focus wheel to coax out even more detail. You’ll be amazed at the amount of detail fi ne focus adjustments allow you to view on targets such as the lunar surface, planets, double stars, as well as other celestial objects.
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