A Busy Day

[Tom Droege <tdroege@veriomail.com>]

Yesterday was a busy day.  First I designed a really kludgy fix for the 
trombone focus.  I put a bar on the end of the focus lead screw which 
attached to the center of the camera bar instead of to one side.  This 
worked.  There is no way I can show what is being done without a drawing, 
and then it is not obvious that it should have any effect.  But it 
works.  It would not work if everything was completely rigid.  If 
everything was completely rigid I could push from one side and that would work.

Next came data taking.  The I camera worked just fine, but the V camera was 
all little angels pointing to the left.  I tried everything to focus it, 
then changed out the camera.  Finally I thought to rotate the lens.  Sure 
enough, there is something tilted in the lens assembly.  I removed the rear 
lens cell and looked at it.  It appeared to have the lenses mounted at a 
slight tilt.  Note that I have had to work a lot on the lens cells since 
the lenses were glued in and broke and ... anyone who has been following 
knows all the problems.  I had to build a new rear lens cell from scratch 
as I have no spares at the moment.  I built it from the new lenses.

This had no effect, but rotation still changed the image.  So I looked at 
the front assembly.  The lens retaining ring was not completely screwed 
in.  This could indicate a front lens problem.  I attached the new rear 
lens cell to a new front lens assembly, and the focus problem went away.

I was now able to focus and took some first light V and I shots with 
MICHAEL.  I then set up to scan the sky and ran the rest of the night 
(until the moon was in view).  The result is two disks full of data that I 
will shortly send to Michael for inspection.  There should be complete 
coverage in V and I for about 12 x 60 degrees of sky.  I have not yet 
looked at the data to see how well the Declination drive is working.

Tom Droege