Update for December 2009

The assembly now has a secondary mirror spider.  I decided to use the Meade spider for now.  If that works OK we may keep it.  The original design called for a rotating secondary and 3 focus place positions, but in the interest of getting the OTA up and running sooner we decided to give this a try and fix the position of the focuser.

Speaking of focuser plates, ours is partially fabricated now for the project.  The plate was formed out of 1/4″ hard plexiglass, and will eventually have an aluminum plate that the focuser will be mounted to.  The aluminum plate actually has 2 positions, one setting for increased back focus.  Please see images below.

View of the secondary mirror with focuser plate removed

Side view of the focuser plate.  An aluminum plate goes under the square hole and this is what the focuser will bolt to.

A view of the under side of the focuser plate and secondary spider.

Focuser plate.  The plate was cut from a single piece of opaque black plexiglass.  The top and bottom edges were heated and bent upwards at 90 degrees to form a more rigid base for the focuser.

Dark skies,

Larry Owens