Fujii with help of Ito, Shimizu from MPC, and R. Takahashi,

1. Since the BF-GAS seemed to be locked based on the TF (klog#6423), I tried adjusting the EQ stopper on the keystone ring. For this purpose, the top flange of PR2 chamber was opened.
-- I made larger gap between the screws/nuts and the BF-keystone. the keystone was touching to the stopper nuts and it went to the lower position after the adjustment. 
-- Actually the york which we adjusted yesterday was not in a straight line. However, when the BF-EQ stop screws were loosened, the BF-keystone started to oscillate (rubbing also existed in some extence though). this might mot be a main reason of the rubbing.
-- However, when all the masses were released, the BF-keystone rubbing effect became larger, especially when the Recoil BF was released. (I'm not sure why for now.)
-- Now the keystone is in a position where it can oscillate (confirmed by time series). all the check with TFs is to be done.

[Note]
-- current SF-keystone heigth was a bit low (~64.5 mm), this is not problem though.
-- Vertical OSEMs are now in better postion for them
-- During the work by MPC, accidentally one of them touched to the optics on the table. this broke the alignment. I sincerely apologize this.