edmond.merilh@LIGO.ORG - posted 16:31, Monday 04 December 2017 - last comment - 07:07, Tuesday 05 December 2017(39628)
IM1 & IM3 Mechanical Alignment
Cheryl, Ed
Ed - IM3 - After re-centering the mounting plates for the leaf springs to better center the wires in their spaces, I was able to recover a good portion of the YAW alignment as it was after I zeroed the sliders. Pitch requires the removal of the baffle which was not done at this time. Images below show values before any work was done and then what I finished the day with. More aggressive physical positioning may be required to recover best alignment.
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Comments related to this report
IO work, 4 Dec 2017:
IM1 - bias relief and viton pads installed
- removal of the baffle altered the IM1 tower enough that pitch and yaw changed by up to 50urad
- bias relief in pitch was difficult as usual
- for bias relief in yaw I used more than one strategy, in that I moved the plates that hold the blade spring and it's mount, and also adjusted yaw using the blade spring adjustments screws, which proved to live up to a comment made during installation in 2012 - they're touchy
- reinstalling the IM1 baffle revealed two new pieces of information
- the flat washer-type viton is going to be the best option for installing between the SiC baffle and the IM towers
- in the case of IM1, there's a baffle that sits very close to the optic, and I had to remove that baffle in order to install the viton on IM1
- the interference was the nut on the 1/4-20 bolt, and not the baffle itself, so I'll be altering the bolt/nut installation in order to reinstall the baffle
IM3 - work continues
- the wires suspending the optic were only 1/4 of the slot width away from the front side of the slot, irrespective of any bias I put on the optic
- Ed's alog indicates he was able to adjust that placement to better center the wires
- still to do: baffle removal and adjustments to pitch and viton/baffle install