The design of the addtional steel support structure is based upon extending the existing six-point hexagonal strong-back design of the Kennedy dish to form a second hexagon structure in the same plane as the original hexagon but with the new hexagon vertices exactly underneath the rim of the current dish. The six new extension petals that form the annulus will be supported by bolting/clamping upper and lower extremeties of each petal onto the existing rim of the dish and onto the new steel hexagon structure. The project is being performed without unmounting the current dish; instead, temporary scaffolding will be used to gain access the dish edges and the new components will be added to the existing structure piece at a time from the scaffold position. The details of the new petal design are a straightforward extension of the structural design that was used for the existing Kennedy petals, except that 1-1/2" square x 1/8" thick tubing will be used in place of the 2" round tubing in the original design and 1" square x 1/16" thick tubing will be used in place of the 1-1/2" round tubing of the original Kennedy design. The new design has been put into TurboCAD for the Apple Mac computer and is used to check dimensions and final fit before cutting metal.

DISH EXTENSION CONCEPT DESIGN VIEWS (September 2009)

 

Figure above: Steel support structure to be fabricated and added to the existing steel structure of the mount. Blue circles are positions of the existing 340" dish rim and the new 480" dish rim. Support arms are 3" x 1-1/2" x 3/16" thick steel channel. Hexagon sides are 2" x 1" x 3/16" thick steel channel. Bolt plates are constructed of 6" x 6" x 1/4" steel strap drilled to accept four 1/2" x 13 tpi steel bolts and nuts each.

 

Figure above: Structural design of one of the six identical extension petals that will comprise the extension annulus. Dark lines are constructed using 1-1/2" square x 1/8" thick aluminum tubing. Light lines are constructed using 1" square x 1/16" aluminum tubing, except for the annular rings which are constructed using 1" dia. circular aluminum tubing. Aluminum members in each petal will be welded together using an aluminum spool gun MIG welder. During installation onto the dish, petals will be bolted to each other to form the annulus.

Figure above: Six-petal annulus shown assembled. Annulus diameter is 480" (12.1 meters).

Figure above: Top view of annulus.