Betsy, Travis

This alog represents the last ~month of intermittent assembly work on the 3IFO QUAD unit "Q7".

After switching out 3 problematic wire segments and the entire set of top stage blade cartridges, we have finally launched a first round of testing on Q7 this morning.

Details:

After assembling and fully suspending Q7, we had a difficult time bringing the 6 DOFs of each chain into coarse alignment.  We discovered that the top most blades used in the QUAD were the softest of any QUAD unit thus far, as per the stiffness catalog T1000068.  In fact, this set had a much wider variation in stiffness than any other unit as well which was adding to our challenge.  We decided that we should delegate this set of blades to the spare bin and swap them with another set.  After swapping in a set from the middle of the stiffness range (Tops Set 7), we saw the QUAD chain alignment was much improved in side shift.  We then continued to struggle with differential height.  We decided that we might have had a wrong wire segment length lower in the chains so we first switched in new main chain PUM loop which had no effect, and then switched in a new set of reaction bottom and final wires which did help our differential height issue.  (We confirmed the removed sets were ~1-2mm longer than the new set although we really don't know which is "correct".)   With all of this new hardware, we were able to align the chains to within the coarse specs.  We laced up the reaction chain lower stages and readjusted alignments and suspension mechanical groundings.  Yesterday we assembled the top mass tablecloth and cabled/attached/aligned top 12 BOSEM sensors.  Today we are running TFs.