= Tip/Tilt Suspensions =

For the PRC/SRC folding we will use Tip/Tilt stages modified to be used passively.  No active damping, no coil drive. Just magnets and natural eddy current damping.

We have got five initial TT delivery. 4 is for the PRC/SRC folding. 1 is for tests/spare. We would employ 4 more TTs for the Input/Output steering, though we should seriously consider the foot prints of them.

   * [[https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=7074|Bram's TT assembly document on the dcc]]

   * [[http://ilog.ligo-wa.caltech.edu:7285/advligo/Tip-Tilt_Stage/Tip-Tilt_Mechanical_Design|Bram's TT wiki / drawings]]
   
[[Suspensions/Tip_Tilts_IO|We are using 4 newer versions of the TTs for the Input/Output steering.]]

== TT SolidWorks models and drawings ==

There are many TT versions and hence there are many SolidWorks models too. Dependencies of the components are quite complicated. Here the SolidWorks model for the 40m passive tip-tilt with a modified mirror holder is packed.

{{attachment:40m-tt.jpg}}

[[attachment:D09xxx_00_TipTilt_Assembly_SECD.easm || eDrawings file ]]

[[attachment:D09xxx_00_TipTilt_Assembly_SECD_40m.zip || SolidWorks file (made with an educational license. Don't mix any component in an aLIGO model]]

== Assembly and Installation ==
 . We will employ vertical springs designed by Valera@LLO. Mike@LLO suggested the items additionally needed for attaching the vertical springs.

 || '''Qty.''' || '''DCC No.''' || '''Item''' ||
 || 2 || [[https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=2836|D0901164]] || Blade Spring ||
 || 2 || [[https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=2837|D0901165]] || Blade Wire Clamp Block ||
 || 2 || [[https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=2838|D0901166]] || Blade Wire Clamp ||
 || 1 || [[https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=3653|D0901404]] || Blade Spring Mounting Platform (Active Tip-Tilt) ||
 || 1 || [[https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=3682|D0901409]] || Viton Damper Mount ||


=== Issues ===
 . There was a problem of the backplane. A beam of the backplane blocked the laser light goes through the TT optic.

{{attachment:TT_crosssection.png}}

 . {i} ''' The design has been modified to address this issue.''' 
   . The modified design is here.  [[attachment:TT_ECD_Drawings_for_40m_100215.pdf]]

=== Design/Installation/Assembly Details ===
 .  '''Baking order to Bob:  ''' [[attachment:TTparts_2010-03-11_K_Arai.xls]]

 . '''Magnets: '''10mm dia. 10mm thick SmCo magnet pressed in the mirror holder.

 . '''Wires: '''<200um musical wire for the mirror suspension / Bram will  give us tungsten wires.

 . '''Titanium screws:''' We try grade 3 cheap Ti screws (#2-56 3/8") ~$1.3ea (c.f. McMaster ~$15ea)

 . '''To Do:'''''' '''Wire Jig drawing




== Links ==

   * [[Compliant_Eddy_Current_Damping_in_Suspensions ]]
   
   * [[ https://nodus.ligo.caltech.edu:30889/wiki/doku.php?id=surf2011:ttsuspension | Summer Project 2011 ]]