On Wednesday 6/8 we collected the repaired flags from TAMA and took the dummy BS, flags, prisms and gluing equipment to Kashiwa.
We checked with Hirose-san about the intended orientation of the BS. We realized that the dummy BS drawing D1604820-v1 is ambiguous and we had assembled it upside down, so we rearranged components accordingly. The correct orientation is with the arrow pointing from right to left as viewed from the side as shown in the drawing of the main body D1604820-1 but not in the top assembly. Hirata-san will put an extra view in the assembly drawing showing the arrow.
Then we assembled everything without glue for a fit check. Everything was fine except that the locating pins for the left secondary prism holder were a bit short, so that one of them failed to touch the side of the holder. Since the secondary prism position is not critical and the uncertainty in position was only a fraction of a millimeter, we decided to go ahead. See attached photo.
We used sapphire prisms #5 and #6 (of 6). We were careful to place them groove-first in the holders so the grooves would end up outermost after gluing (likewise for the secondary prisms).
We put flags with the N pole at the tip end in the upper left and lower right positions, and S ones at the upper right and lower left.
Finally we mixed glue with beads and applied it to all the flags and prisms. (When looking at the photos, note that we did the flags anticlockwise from lower right.)
We will come back on Monday 6/13 to check the status.
Photos of this and other BS Test Hang stuff are at https://goo.gl/photos/tVGoebw7FTRMAYB2A .
