GHRIL derotator Change Checklist

Jürg Rey 5 December 2007
Revision 1.0

Description: WHT Ground-Based High-Resolution Imaging Laboratory
Location : WHT Nasmyth Focus

Installing the optical derotator:

Team required :  3  (e.g. 3 mechanical)
Approximate time :  30 minutes

This should be carried out at least the day before the instrument is setup on the table.

IMPORTANT: Disable limit switches! Derotators have NO rotation limit while INTEGRAL must have the mechanical limit at the 0 degree mark on the rotator in place. This consists of a mechanical cam screwed on the rotator.

Tick each box when complete	Tick box
1. Locate the derotator box in the WHT dome area and lift the derotator into GHRIL. Bracket and sling attached.
2. Rotate GHRIL rotator to get access for removing the limit cam at the 0 degree mark.
3. Rotate GHRIL rotator until the 180 degree mark on the rotator is on the top.
4. While 1 person is lifting the derotator on the sling standing on the bench, 2 people need to push the rotator against the flange while at the same time supporting the weight and fasten the 6 screws.
5. Rotate GHRIL rotator to the 0 degree mark.
6. Mount the counterweight.
Preparation Complete                     Signature :                                                           Date :

Removing the optical derotator:

Team required :  3  (e.g. 3 mechanical)
Approximate time :  30 minutes

This should be carried out at least the day before the instrument is setup on the table.

IMPORTANT: Enable limit switches! Derotators have NO rotation limit while INTEGRAL must have the mechanical limit at the 0 degree mark on the rotator in place. This consists of a mechanical cam screwed on the rotator.

Tick each box when complete	Tick box
1. Rotate GHRIL rotator to get access for removing the counterweight.
2. Remove the counterweight.
3. Rotate GHRIL rotator until the 180 degree mark on the rotator is on the top.
4. Mount the bracket holding the sling for lifting the derotator.
5. While 1 person is holding the derotator on the sling standing on the bench, 2 people need to undo the 6 screws. When undoing the last screws push the rotator against the flange before slowly removing.
6. Rotate GHRIL rotator to get access for mounting the limit cam at the 0 degree mark.
7. Store the counterweight in the box below the rotator and the derotator in its box in the dome area.
Preparation Complete                     Signature :                                                           Date :

JR Revision 1.0, 05/12/2007