Date: Mon, 6 Dec 1999 10:59:42 -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, toomey@jeans.ifa.hawaii.edu,
    vern@hokuhele.ifa.hawaii.edu, watanabe@jeans.ifa.hawaii.edu


Vern and Ray are working on the GT trying to
understand exactly what is moving. There are
several possible simple fixes which we can try
over the next day or two. Doug Neil and Vern 
have suggested extending the GT axial all the
way to the cover plate. This separates the 
bearings and seems to me to be the best way
of fixing the flexure. This redesign and fabrication
will take about two weeks assumming there are no
show stoppers fitting it into the space available.
With your input I'll decide whether to pursue this
once the simple fixes are tried.

I don't plan on a cooldown until we have a solution
which works warm.

The science grade 1024x1024 will arrive in the next
few days. Once it is here we need to mount it in
the spectrograph mount for cold testing in the 
lab test dewar. This will mean using another mount
in the spectrograph to continue flexure testing
with the mux. Peter says we have a spare we can 
use. This allows us to do these tests in parallel.
Peter will figure out the best way to use the
readout electronics but it might mean swapping
things between the cryostat and lab test dewar.

Before removing the mux from the spectrograph
mount we must measure the position of the mux
in the mount very carefully so that we know
exactly how to position the science array/mount
relative to the optical beam. Peter/array, 
Vern/mount and John/optics will need to co-ordinate.

The cal box fabrication is almost complete. Greg 
is assembling and pinning the mounts. I'll let 
Darryl know when he should come across and start
work on installing the lamps and power supplies.

Over the next week or so Greg will be variously
occupied with taking things in and out of the
cryostat (GT, guider filter wheel, spectrograph
detector mount). He's also working on a plan for
shipping SpeX.

The bottom line is that by using the spare mount
in the spectrograph we can make progress on the
science array testing in parallel with fixing the
GT.

Please think about the implications of this and
let me know if there are other things we can do
to maintain a schedule for shipping about April 1.
This includes mountain issues (MIM mount, counter-
weights, cooler plumbing, chiller etc.).

Thanks,

John