Mirror Covers
Secondary Mirror Cover
The Secondary Mirror Cover (Figure 1) should be installed so that the blue arrow is up when the telescope is in the stow position (pointed south and telescope truss tube parallel to the floor).
Make sure the dome shutter is open before removing the secondary mirror cover so that the mirros is protected from any dust or debris falling from the dome shutter during opening. Likewise, make sure the secondary mirror cover is installed before closing the dome shutter.
To remove the cover, carefully reach into the truss tube and pull the cover straight off away from the mirror. Do not twist or rotate the mirror cover. Take care to not touch the mirror surface. Set the mirror cover carefully on the desk for safe keeping during the observing session.
To install the cover, align it so the blue arrow is facing up when the telescope is stowed and carefully install it over the mirror, taking care to not touch the mirror surface.
Figure 1: Secondary Mirror Cover in Stow Position
Primary Mirror Cover
The primary mirror cover is two leaves that latch at the center to protect the mirror (Figure 2). Please make sure to not touch the surface of the primary mirror while opening or closing the mirror cover. It is challenging to get one's arms and hands through the truss tube structure to get to the mirror cover and its latches.
To open the mirror cover, do the following:
- Make sure dome shutter is open before opening the mirror cover. This ensures that the mirror is protected from any dust or debris falling from the slit shutter during opening.
- Rotate the mirror cover lock clockwise (up) to unlock.
- Flip open the top mirror cover using the tab (not the spring) and attach to the upper mirror cover latch (Figure 3).
- Flip open the lower mirror cover and lower it gently and latch to the lower mirror cover latch (Figure 4).
To close the mirror cover, do the following (and close the mirror cover before close the dome shutter):
- Unlatch the lower mirror cover by pushing out (towards secondary mirror) on the latch.
- Fold in the outer flaps of the lower mirror cover slightly as you raise the lower mirror cover (Figure 5) until cover raised to about 45 degree angle.
- Continue raising the mirror cover until it is flat against the primary mirror.
- Unlatch the upper mirror cover.
- Gently lower it until it meets the lower mirror cover.
- Rotate the lock counter clockwise (down) to secure the mirror cover in the closed position.
Support Astronomers Last modified: Wed Feb 5 13:22:04 PST 2025