DETAILS OF THE TELESCOPE USED ON THIS WEBSITE

This photo shows the constituent parts of the present Galilean telescope (above, numbered), and the complete assembled telescope (below). Click on it to see a larger version.

Part Descriptions:

1. Main tube:
   • PVC 1-¼" 160 PSI tube, 34" long.
2. Focusing tube:
   • plastic 1-½" x 12" tailpiece (under sink drainpipe), end flange cut off.
3. Eyepiece and objective mount holders:
   • Left: 1-¾" piece of straight section.
   • Right: 2" piece of end (coupling) section.
4. Eyepiece and objective mounts:
   • Nylon (Hyco) electronic box hole bushing marked KSS, 3B-30

The above parts can be obtained from Home Depot or Lowe's. The bushings from a large hardware store.

Assembly Directions:

1. Cut plastic to length and smooth ends. Objective lens end of main tube can be squared by standing tube on end on sandpaper and rotating until tube is vertical when rotated.
2. Focusing tube (2) will need one or two pieces of masking tape lengthwise until it moves easily in and out of main tube (1) and will snug up upon rotating it.
3. Eyepiece and objective mount holders: The eyepiece end (3) is wrapped with 5 or more layers of masking tape and then thinly coated with 5 min epoxy and pushed into focusing tube (2) about 1 inch. The large end of the objective mount holder 2" piece is treated the same as the eyepiece end.
4. Eyepiece and objective mount bushings have four little snap tabs that must be cut off with small wire snips. Lenses are mounted with a small amount of RTV around their circumference. Bushings are simply pushed into ends of tubes.
5. Telescope is spray painted from both ends with tube in the vertical position. Several thin coats are better than a thick one, as a thick coat will be shiny.
6. If baffles are desired they can be made from "Darice" brand black extra thick ¼" (6 mm) foamies, available from arts and crafts stores. If a tube section of the size to match the end product tube is beveled inward on the outside and the foamies material put on a scrap piece of plywood the tube can be pounded thru the foam with a hammer, and the opening similarly hammered through with a curved chisel, or cut out with an Exacto.

For details of the lenses used in this telescope and some additional suggestions see our page on Building a Galilean Telescope.

Images © Tom Pope and Jim Mosher
Last modified: March 14, 2006