Next: Relay Mirrors Up: No Title Previous: Equipment requirements
Next: Relay
Mirrors Up: No
Title Previous: Equipment
requirements
Refer to figure 1 for details of the positioning of the components.
All components are positioned on the optical bench relative to one optical axis - the axis through the collimators. It makes sense to use a line of holes, as it is then possible to use the alignment posts to get a laser onto this axis. This axis was taken as the line of holes 16 holes - 425mm - in from the edge of the optical bench. The projection of the pivot point for the camera on this axis (point X) was taken to be 1,425mm from the telescope end of the bench, thus avoiding having either relay mirror one or two colliding with the spectrograph cover.
The slit axis was marked relative to the collimator axis: it crosses
the collimator axis 60.4mm further from the telescope end than X, and making
an angle of 4.51 degrees with it. This is constructed by measurement; from
figure 1, the slit axis is at a distance of 93.5mm from the collimator
axis point A 
, 1125.9mm from point X. This makes the centre of the focal surface 1186.3mm
from A
i.e. 60.4mm beyond X.
The pivot point for the camera is 326.5mm away from the X - note the position of the hole at 325mm from X.
The positions of the baseplates for the collimators, relay mirrors, slit unit and camera are defined using the templates taken from the setup at RGO Cambridge. These should enable positioning to better than 1mm.