The Extreme 18" Aluminum Scope



Upper Cage


This is the upper cage that positions the secondary mirror, focuser and any finderscopes. The main idea is to make this piece as light as possible, since every pound up here requires many pounds of offsetting weight below the balance point for proper weight distribution. We make sure that your telescope will balance preceisely without the need for any counterbalancing measures.







Here are the beginnings of the secondary cage. The rings are 1.25" wide, 3/8" thick Baltic Birch plywood. Using the homemade circle cutting jig, I cut the rings 21.4375"od x 18.9375"id.

Always make the outer cut before the inner cut otherwise you lose your pivot point. Also make all the marks you'll need before you begin cutting.

Here's my faithful helper. She's always there with me with her "party hat" on. Here I'm drilling holes through rings to lighten the cage.

The 18" skeleton cage compared to the 10" cage of my current scope... nice!
Oh, that's not blood, it's the red stain I've been using for the scope.

Update 6/20/02:

OK, I decided to redesign the secondary cage. This time *with* the .171" diagonal offset built right in. Plus I'm making the rings 1/2" instead of 3/8". I will sacrifice a little weight gain (14 oz) for more rigidity. The scope still comes out 98 inch-pounds bottom heavy... YES! (with a fist pump)
It is almost complete, I'm currently staining the rings and will polyurethane them after that. Stay tuned for pictures of the new cage. Actually, just imagine the cage above 1/8" thicker 8^)

Update 7/1/02:

Secondary cage #2 is done.


Looking down the business end of the telescope.

Another shot of the cage.
The Kydex baffle stops unwanted stray light opposite the focuser. The finderscope is the 9 x 50 brought over from the 10".

The nice looking red anodized Moonlite focuser with the lovely Televue16mm Nagler Type 5.