My amateur telescope
The "Deep Space Scope"
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We now have the two ends of the telescope, and need to firmly
them relative to each other.
- Create an optical bench. One
easy way to do this is with a straight 2x6 board or (carefully) a 2x4
First, lay the board outside, on a table or bench, aimed at something a
long way away. The top of a telephone pole will work for an object way
the primary mirror box on it's side onto the end of the board, aimed
at the far away object. Then, somehow attach the secondary cage
to the board, standing up. One way to do this is with wood
clamps. Another would be with a few bricks. Move the
focuser in/out until it is in the halfway position.
Tighten/loosen the primary mirror mount until it is in a good firm
position, not totally compressing the mirror mount springs.
- Place an eyepiece
focuser. Now, move the primary and/or secondary back and forth
until you have a good focus.
- Measure from the attachment points (brass rods) on
the secondary to the top of the primary mirror box. Add 1"
the depth of the truss holes in the mirror box. Add an
1/2" for the distance between the top of the trusses and the holes in
the trusses. Also, add 1" of extra truss, since we
only have a rough estimate of truss length at this point. This is
an estimate of the distance from the top to the bottom of the
- Create the trusses. This is done
using 6 pieces of aluminum tubing, 3/4" in diameter.
When you buy this tubing, get the alloy that you can bend by
pounding. Using a hammer, flatten the tubing for a section
4" long. Use a sander, grinder, etc to round the tops of the
trusses. Drill a hole into each truss, 1/2" from the flat end, using an
diameter drill bit.
- Cut the trusses to the length as
calculated above. Use a hack saw or tube cutter. If you use
a hack saw, smooth the end using a sander.
- Clean up the trusses using a circular
wire brush that goes into a drill.
- Use the trusses to build the
telescope. Placing this contraption onto the 2x6 above, and
aiming at a distant point, check out the length of the trusses.
- If necessary, cut the trusses until
your eyepieces focus in the middle of the range of movement of the
focuser. Be sure to check all of your eyepieces before
- We now have a telescope that needs a