Thirty Inch Telescope Secondary
The secondary is mounted on a motor driven slide.
On the right you can see the d.c. gear motor.
In the middle is an aluminum plate that holds the
Renishaw encoder readout device
that is used to measure the position.
Limits
The motor travel is restricted by the limit
switches shown below.
The limit on the right (nearest the primary)
is the home position (mils=0).
The left limit switch is at about 1360 mils (1.36 inch).
The motor takes about 1 minute to travel 500 mils.
Collimation
The collimation is adjusted manually by tweaking
three push screws.
Two of these large screws can be seen in the photo below.
For a more amusing view of the secondary, go here.
Thirty Inch Telescope
Last updated on 2002 September 17.