How to align the calibration unit
Information on the original alignment can be found here
This is not a routine maintenance procedure.
The procedure should only be done if no alternative are available.
The person executing this procedure must be very familiar with the calibration unit system - mechanics, operation!!
Currently the procedure is not tested and might fail even if followed properly!
As long parts of the swing arm and calibration unit have not be changed or touched we do not expect, that the calibration unit has to be re-aligned!
However, in 2020 we experiences on SX some misalignment in rotation, which required re-adjustment to close day time the loop for the LGS system with the calibration unit.
Therefore, we describe here how to algin the calibration unit in rotation in more detail.
- Allen keys:
- For cover screws: M3
- For cover amr block screws: M4
- For clamp set screw: M2.5
How to align the calibration unit in rotation
The rotation angle can be determined before the calibration unit cover is removed.
Remove the calibration unit cover with the telescope at Horizon
- Remove the M3 screws indicated in the image below. There are loose washers underneath as spacers.
- Remove the cover.
- Put the screws and washers back so you don't loose them.
- Loosen the M4 screws holding the cover arm block, tow on each side (see image below).
- Slide down the block to release tension on the roller arm.
- Tighten screws.
Get the amount of rotation
Entrance window position on patrol cameras:
Entrance window position difference between patrol cameras:
Formula to calculate the rotation angle:
This formula has still to be tested!! Data to do testing is urgently needed!!!
Rotate the calibration unit
- Move swing arm to park position.
- Climb up to the platform where you can access the calibration source.
- Loose the small screw in the cone. Take care! Don't remove the screw because it holds a clamp, which can fall away.
- Turn the unit of the needed amount.
- Check the position on patrol cameras (see previous paragraph)
- Re-do until alignment is perfect
- Fix all screws
- Go back to horizon and attach the cap
- Visual/functional inspection if in all orientations cap, switches, swing arm, etc. works properly
- 24 Aug 2020