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 * Type B Past Week Summary
  * Mark and Hirata-san worked at Kamioka, with valuable help from Enzo (on loan from Type Bp team).
   * We got all the adapter cables for the BF made (Hirata-san did some work on Monday at Mitaka).
   * We installed the extension for the BF yaw pico on the IM pico adapter cable.
   * We got all the in-vacuum and in-air cabling for the IM OSEMs done.
   * We tried to install the stepper and LVDT adapter cables but realized we didn't have enough information on which wires was which. (We later tracked this info down but did not have time to do anything with it - we would have needed to do the rest of the in-vacuum and in-air cabling and set up the stepper motor and LVDT drivers, so we concentrated on the OSEMs.)
   * We plugged in the IM OSEMs, set gains and offsets, and did a noise test (analysis and klog pending).
   * We mounted the OSEMs on the IRM and routed the cabling neatly.
   * We released the suspension.
   * We adjusted the OSEM mounting plates to center the OSEMs on the flags.
   * We adjusted the OSEMs in/out to midrange.
   * The suspension is now ready for OSEM-OSEM TFs!		  * 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).

Scraps of text for incorporation in the VIS Meeting Minutes

KAGRA/Subgroups/VIS/MeetingNAOJ

  • 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).

KAGRA/Subgroups/VIS/TypeB/Minutes (last edited 2022-10-28 10:02:46 by fabian.arellano)