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Mirror box for the 6-inch

The mirror box has an aluminum handle  
from a kitchen drawer that allows it to be
easily carried on the plane.  It is 8x8x10
and made from 1/2" plywood. 
A top and bottom of 1/4" plywood velcros
on to protect the mirrors which are inside.
  This shows the top of the mirror box
  removed revealing the focuser board
  with the focuser near the top.  The  
  board rests at the corners on 1/4 round
  and stays in place with velcro.  A
  slight tug removes the focusing board.
 

   The focusing board not only holds  
   the focuser, but also the secondary  
   mirror which is glued (silicone) to
   a brass single-stalk holder. 


   To collimate the secondary you
   first adjust the distance from the
  board to the secondary (see below)
  and then bend the stalk to get good
  collimation. Crude, but effective.

   The brass stalk for the secondary 
   goes through a hole in the focuser  
   that I drilled and fits into a piece of
   aluminum with a lock bolt that
   tightens it as shown.  By pushing
  it in or out of the hole, the secondary
  mirror can be accurately aligned with
  the primary mirror.

   The focuser is from AstroSystems
   It is a Phase 4 (Very nice).  The
   secondary mirror is from Orion
   and seems to be fine.

   Removing the bottom piece of 
    1/4" ply  reveals the collimation
   bolts.   They are #10-32 bolts
   with tapered heads that snug down
   (and are glued - silicone) into 
   countersunk holes below the mirror.

  The mirror cell (pictured below) is
 two pieces of 3/4" ply held apart by
 strong springs that the collimation
 bolts go through.  By tightening or
 loosening the wing nuts shown here,
 the two boards are pulled together or
 pushed apart (by the springs).

The white page-reinforcing ring is to aid in collimation with a laser collimator.
   The mirror cell is very similar   
   to the one described in Berry's  
   book (pages 86 & 87) except for
   the collimation bolt system
   described above.

  The mirror is held in place by
  silicone glue as Berry describes.


   The bottom board is bolted into
   the box by bolts and furniture nuts
  (two nuts are shown here and you
  can see all 4 in place in the picture
  above). This allows adjustment of
  the mirror (cell) in the box.

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