From rayner@galileo.ifa.hawaii.edu Fri Dec  3 10:05:38 1999
Date: Wed, 1 Dec 1999 18:43:06 -1000 (HST)
From: John Rayner <rayner@galileo.ifa.hawaii.edu>
To: bergknut@jeans.ifa.hawaii.edu, denault@jeans.ifa.hawaii.edu,
    gching@galileo.ifa.hawaii.edu, kuwata@jeans.ifa.hawaii.edu,
    neill@galileo.ifa.hawaii.edu, onaka@jeans.ifa.hawaii.edu,
    rayner@galileo.ifa.hawaii.edu, rayner@galileo.ifa.hawaii.edu,
    toomey@jeans.ifa.hawaii.edu, vern@hokuhele.ifa.hawaii.edu,
    watanabe@jeans.ifa.hawaii.edu


Following mods to the GT I retested for flexure
today. Flexure (0 to 60 degrees tilt) is much better:

Axis 1     dx   dy
spec        1   1
before     12   2
now         2   0

Axis 2     
spec        1   1
before      2   2
now        0.5  1

This was achieved by increasing the bearing load
from 20lb-f to 80lb-f and which should reduce the
movement in x (wavelength) by about 4 times as 
observed. There was obviously some coupling into
y (along slit). 

Other mods to the GT included a debris shield and 
pinning the Hall Effect mount.

Vern checked the limits on bearing load and
has concluded that it can be safely increased to
170lb-f which I've asked him to do. He will also
increase the load on the worm and on the angular
contact bearings. If things still scale these 
these mods will bring us to within spec.

During testing this morning we noticed that the
guider filter was working but running very noisily
probably due to an assembly problem.

Plan:

Thursday am -  Remove GT (Greg)
               Re-assemble guider filter wheel (Greg)
               Mods to GT (Ray and Vern)
               Using jig plate, drill holes in top of vacuum
               jacket for cal box plate (Shonn) 
 
         pm -  Install GT (Greg)
               Install prisms (John)
               Flexure test (John)


Friday       - If all OK, close up cryostat and pump (Greg)

Saturday     - Leak test (John)

Monday 12/6  - Cooldown  (Greg and Lars)

Wednesday    - Cold tests (John)
Thursday

Friday       - Start warmup

Monday 12/13 - Open up
 
December       Prepare cryostat for science arrays:

               Assemble and test cal box (ideally using a mux)
               Install all available filters
               Mods to improve access to filters?
               Metrology of muxes
               Remove muxes from mounts and install arrays
               Test 1024 array+mount in lab test dewar 
                 - H filter test
                 - blank-off test
               Test 512 array+mount in lab test dewar? 
               Install arrays in cryostat
               Cooldown


Please think about the schedule and let me know what you
think.

Thanks,

John