Tools Required:

• 7/64 T-handle allen wrenche
• Palm grip handle tool found in the LRIS storage area on the Keck 1 Nasmyth deck or in the instrument lab LRIS cabinet (bin marked special tools).

Procedure

Log in as lriseng and bring up a punaluu xterm window. Type the following command at the punaluu prompt:
• s gristran (should read gristran=stowed; if not type m gristran=0 to move the grism into the carousel)
• grisload.tcl (This will bring up a small GUI window which allows you to rotate the appropriate carousel.)
1. Rotate LRIS to the fill position so that the grism carousel is at the top of the instrument. This will make it much easier to load and unload the grism.
2. Click on the position number you wish to remove, and click the SET button to move the carousel. The carousel is now in position for replacing the grism.
3. Climb on top of the instrument and locate the carousel.
4. Pull the tethered T-handle pin which locks the load door in place. Note: The pin is an interlock for the carousel!
5. Open the load door.
6. Screw in the palm-grip handle. This allows you to lift out the filter, and also locks down the latching mechanism to the cell assembly.
7. The holder is kept in place using 3 or 4 screws which secure the optic cell around the edge of the plate. Use a 7/64 allen head wrench to loosen these captive screws until they rattle.
8. Carefully lift the grism out of the carousel.
9. Place the grism to be serviced in its storage case or cart.
10. Remove the palm-grip handle from the grism.
11. Close the load door.
12. If removing more than one grism, repeat steps 3 thru 12.
13. Insert the tethered T-handle which locks the load door in place.

Pictures with the 7/64 T handle in one of the four retaining screws and the palm handle inserted.