2001/05/24

"Big Ben" the warm bulkhead and telescope mount unit on the lathe for insertion of O-ring groove and G10 collar groove.
Front side detail showing pass holes and threaded holes for NW40 vacuum fittings for electrical feedthroughs, vacuum ports, and vacuum sensors.
Backside detail showing NW40 pass holes, cryostat main O-ring groove (just inside of the outermost hole circle, and the groove to hold the G10 collar connecting the warm bulkhead to cold bulkhead and cold bench.
Back view of Big Ben on lathe. Inner groove is to contain G10 collar to be cemented in place with epoxy.
Cold bulkhead being machined. Central opening is to accept collimator optics unit. Outer ring of rectangular openings are to hold electrical feedthroughs from the warm to the cold environments.
Front cover and window holder before holes for mounting bolts were drilled.
Domenic Sarcia painting epoxy onto woven fiberglass fabric as the main G10 collar is wrapped for fabrication. This G10 collar carries the entire weight and moment arm of the cold bench and optics and acts as a thermal barrier between the warm bulkhead and the cold mass.
Detail of Domenic painting epoxy onto fiberglass fabric. A tight wrap was needed to achieve the necessary strength, so a combination of light epoxy painting and excess epoxy removal by straightedge were employed.
The final G10 collar, as wrapped in our lab, still on its custom mold and before final machining at the shop.