This past week the observatory used 5 days and nights primarily to work on the shutter drive assemblies. This work was a carry over from last summer when the drive boxes were replaced. At that time 1 of the new boxes developed a leak and it turned out while these were exact duplicates of the originals, they were improperly specified for our application back in the 1980s. Consequently the only solution was to have new units designed for our application installed. The following is a short summary of the engineering activities of the week. The enclosure shutter drive repairs were completed for both the left and right shutter. The refurbished and modified drives that were installed are not leaking like the one installed last summer. We found that drive to be nearly empty of lubricant as feared. The double seals on the downward facing shaft flanges should prevent the failure mode we experienced with the original drives and the 1 new drive. Other improvement are properly placed refill plugs, modified inner seal, and low temp oil. Doors open and close smoothly. Motor currents look nominal. No work on the wheels, bearings, or rails was accomplished but some work is still planned for the June engineering time. Dome exterior paint touched-up since we had the lift handy from the shutter work Grim evacuated and cooled. Dis red camera noise was improved significantly by the grounding of the power supply returns. -- Mark Klaene Observatory Engineer, Deputy Site Manager voice: 505 437 6822 Apache Point Observatory fax: 505 434 5555 PO box 59 2001 Apache Point Rd Sunspot NM 88349 APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 671 in the apo35-general archive. You can find APO the archive on http://www.astro.princeton.edu/APO/apo35-general/INDEX.html APO To join/leave the list, send mail to apo35-request@astro.princeton.edu APO To post a message, mail it to apo35-general@astro.princeton.edu APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO