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* Activity report for week of 12/12 * Mark, Fabian and Enzo continued BS Test Hang work: * We shipped BS mirror box parts to Shoda-san and components for a new LVDT cable to Hirata-san. * We posed for pictures of the BS by a team from National Geographic. * We installed the BF fishing rod stepper motor adaptor cable. * We tried to install the BF LVDT cable but first we encountered trouble routing it, and then several wires broke at the D-Sub end. * We laid 6 in-air cables from the tank to the PR2 rank for BF and SF picos, steppers and LVDTs. * We lifted the BF/IRM/IM/RM/BS section to weigh it and check its balance. * It was 195.6 kg, which is 18 kg(!) less than the capacity of the SF. * There was a major imbalance in roll: with all four built-in trim masses moved up the +Y end, it still needed 270 g of extra trim mass to be level. This can probably be made up easily by designing the 18 kg of extra mass appropriately. * Unfortunately when we put the payload, the IM was slightly yawed and ended up on the horizontal EQ stop screws. This let the IM-BF maraging rod go slack, which disturbed the leveling of the IM (because every time it is picked up the maraging rod settles in a different place, giving a different suspension point). * We removed the end panels of the IRM to get access to the IM and rearranged the trim mass on the the IM to get it balance to bubble-level precision. (We still need to do fine pitch adjustment with the OL so that the BS is at the right angle, secure the trim mass properly and replace the IRM panels and OSEMs.) * Miyakawa-san and Yamamoto-san redid the cabling from the computer room to the PR2 rack and expected to finish by lunchtime on Friday. * Hirata-san * Did parts and fastener lists for the SR payload. * Did a 3D model with the SR suspension on the BS assembly frame (to help Mark make adjustments to the frame design). * Did 2D drawings of Fabian's concept for BS EQ stop parts. * Did a 3D model of a wire clamp with replaceable jaw parts (to avoid having to reuse parts with scars from pressure). * Did 2D drawings of a new wire clamps for on top of the BS and SR RMs. * BF issue * The BF has three issues that may or may not be related: * The keystone is sitting at an angle, which means: * The bottom of the keystone just barely clears the magnet yoke without rubbing. * The suspension point for the IM rod is offset, so the BF does not hang level, even with all built-in trim masses moved to their limits (an additional 270 g stacked on the +Y side of the cap is required). * The load capacity is slightly less than measured by Hirata-san during tuning at the ATC. * The frequency is rather higher than measured by Hirata-san. * Also, the BF/IRM/IM/RM/BS system is 18.1 kg light (195.6 kg) compared to the load capacity of the SF (213.7 kg). |
* Hirata-san: * Updated the 3D assembly model for BS (among other issues, it turned out that parts were not correctly mated near where the suspension sits on the hydraulic jacks in the tank). * Liaised with IJECT. * Made an inventory for Type B (BS and SR). * Packed and shipped second winch to Kamioka. * Packed some jigs for adjusting BF blades. * Attended NINS information security seminar. * Attended the public hearing for the Opt-IR Research Division Chief Election. * Mark, Fabian, Enzo * Cabled IM picos and used IM yaw pico for adjusting RM. (Later, a wire broke at the connector, disabling the IM yaw, but we were able to continue by manually rotting the pic.) * Helped Takahashi-san in adjusting BF. * Initial round of adjustment made transverse perfect but overshot in longitudinal and made vertical unstable. * Second round of adjustment made vertical stable but left longitudinal offset. * Concluded that we can probably manage without bringing the BF back to Mitaka, but it will take some careful surveying of the existing offset and several more days of adjustment. |
Scraps of text for incorporation in the VIS Meeting Minutes
KAGRA/Subgroups/VIS/MeetingNAOJ
- Hirata-san:
- Updated the 3D assembly model for BS (among other issues, it turned out that parts were not correctly mated near where the suspension sits on the hydraulic jacks in the tank).
- Liaised with IJECT.
- Made an inventory for Type B (BS and SR).
- Packed and shipped second winch to Kamioka.
- Packed some jigs for adjusting BF blades.
- Attended NINS information security seminar.
- Attended the public hearing for the Opt-IR Research Division Chief Election.
- Mark, Fabian, Enzo
- Cabled IM picos and used IM yaw pico for adjusting RM. (Later, a wire broke at the connector, disabling the IM yaw, but we were able to continue by manually rotting the pic.)
- Helped Takahashi-san in adjusting BF.
- Initial round of adjustment made transverse perfect but overshot in longitudinal and made vertical unstable.
- Second round of adjustment made vertical stable but left longitudinal offset.
- Concluded that we can probably manage without bringing the BF back to Mitaka, but it will take some careful surveying of the existing offset and several more days of adjustment.