Collimators Positioning Positioning

Relay Mirrors

Set two of the alignment posts on the collimator axis, one towards each end of the optical table, 425mm from the edge of the optical bench. Mount one table extension onto the telescope end of the table, set up a laser with its beam going through the tips of the alignment posts. Do the same at the opposite end of the table. Make sure the rails are firmly clamped to the extensions. Put crosswires onto the front of the relay mirrors, marking their centres. Using the template from RGOC, position relay mirror 1 (R ) onto the optical bench. The laser beam should hit R 7.5mm from the centre of the mirror - i.e. 93.5mm from the straight edge of the mirror. Measure the position from A to X (put one alignment post in here temporarily) - this should be 1104.6mm. Position the second relay mirror (R ) in a similar fashion, except it should be 1100.2mm from X. To tune the angles, set up a laser going from the transmission position, through the pivot point (326.5mm from X) and onto the centre of R . Track this onto the centre of R by tweaking the tilt of R . Then track the beam back onto the pivot point by tweaking the tilt of R . Fix the baseplates securely to the optical bench, and lock all adjusting screws on the kinematic mounts. The relay mirrors can then be removed as a complete assembly in their mounts by releasing the kinematic seats fixing them to their baseplates. The table extension at the door end of the optical table can be removed once the relay mirrors have been accurately positioned.