1 LBT Q Eng/SW Review SHTR: Shutters

2 Highlights (Q1/2009) Shutters have been working well, generally Shutters have been working well, generally Latch stations have been performing well, however, we have found that the bolts used as pivots loosen with time, added to PM schedule Latch stations have been performing well, however, we have found that the bolts used as pivots loosen with time, added to PM schedule Discovered bolts on the lower right shutter door drive sprocket were broken off and the door would not move. Lucky the door was closed when this happened. Discovered bolts on the lower right shutter door drive sprocket were broken off and the door would not move. Lucky the door was closed when this happened. All of the bolts on the other 3 couplings were also broken or just about to break. These were caught before any damage was done. All of the bolts were replaced with grade 8 bolts and torqued to 100 lb-ft. We continue to re-torque these bolts weekly. All of the bolts on the other 3 couplings were also broken or just about to break. These were caught before any damage was done. All of the bolts were replaced with grade 8 bolts and torqued to 100 lb-ft. We continue to re-torque these bolts weekly.

3 Open Issues Technical Technical Access for shutter door repair and installation of the donuts Access for shutter door repair and installation of the donuts Access for repair of the shutter door dampers Access for repair of the shutter door dampers Schedule Schedule SL1007 problems with cone and balls, ball motor gear broken SL1007 problems with cone and balls, ball motor gear broken Install new donuts Install new donuts Install new pin design and modify ECS PLC code Install new pin design and modify ECS PLC code Financial Financial Cost of spare parts. Cost of spare parts. Cost of new pins and receivers Cost of new pins and receivers Resource Resource Time to work on the shutter with the telescope in the right orientation and weather, limit access Time to work on the shutter with the telescope in the right orientation and weather, limit access

4 Planning (Q2/2009) Maintain shutters Maintain shutters Fix right shutter door upper drive Fix right shutter door upper drive Grease the shutter track Grease the shutter track Fix SL1007, pull pin and rework cone and balls Fix SL1007, pull pin and rework cone and balls  Finish repair of SL0716 Modify ECS PLC code for the new pin and socket design Modify ECS PLC code for the new pin and socket design Install new pin and socket design on one of the out board stations Install new pin and socket design on one of the out board stations Install the cable and pulleys to manually close the shutter doors, if necessary Install the cable and pulleys to manually close the shutter doors, if necessary Determine why the analog output module for commanding the shutter door motion changes output with time Determine why the analog output module for commanding the shutter door motion changes output with time