I chose a 6-inch f8 design to build my telescope from. This size combines a reasonable cost for mirrors, a high-contrast image for planetary viewing, and a wide enough field for deep-sky viewing. It's a good first telescope size, and a good combination size for all kinds of viewing.
Here are the parts I purchased, and what they all cost. I bought almost everything from Home Depot -- my favorite store! The primary and secondary mirrors came from Orion, and they turned out to be excellent optically, no regrets there.
| Quantity | Item | Cost |
| 1 | 4 ft. by 2 ft. .75-in Plywood Sheet | $ 9.25 |
| 2 | 18-inch pine pre-cut circles | $ 13.50 |
| 1 | 8-in. Quick-Tube concrete tube | $ 4.38 |
| 1 | 1.25-in. PVC conduit cap Female | $ .83 |
| 1 | 1.25-in. Sink Drain Extension | $ 2.25 |
| 1 | 1.25-in hardwood dowel, 36-in. long | $ 4.00 |
| 1 | .75-in by 2-in birch, 36-in. long | $ 2.00 |
| 2 | Cans flat-black spray paint | $ 5.64 |
| 2 | Cans gloss white spray paint | $ 5.64 |
| 2 | Cans navy blue spray paint | $ 5.64 |
| 4 | Cans gray primer/sealer spray paint | $ 5.64 |
| 1 | Can gloss black spray paint | $ 2.82 |
| 1 | 33 RPM record (Pink Floyd!) | $ .33 |
| 3 | 2.5-in. Magic Sliders | $ 2.50 |
| 4 | 1.0-in Magic Sliders | $ 1.25 |
| NA | Various bolts, screws, washers, sandpaper | $ 3.00 |
| 1 | 6-in. f8 Primary mirror | $149.00 |
| 1 | 1.3-in. secondary mirror | $ 33.95 |
| Total Cost: | $251.62 |
The design is a classic Newtonian telescope design, on a Dobsonian mount. The Dobsonian
mount was devised by John Dobson of the San Francisco Sidewalk Astronomers (Visit them here),
as an easy-to-build, inexpensive yet sturdy and useful telescope mount. It is by far the most
popular design among telescope makers today. Below are the plans and specifications I used
to build my particular scope:
I used NEWT 2.5, a freeware program available here
to design the optical part of the telescope, as the image shows. This is a wonderful program that will let you lay out
all of the parameters for your scope, and see how everything fits together optically. Highly recommended!
Here are two drawings that show the side and top view of the mount design. The base is made of the two pre-cut 18-inch pine circles. I cut plywood sideboards that mount on top of the base, 24 inches high and 13 inches long. Two cross-braces made from the birch wood cross the sideboards at the front to provide stability. A .5 inch shoulder bolt, 3 inches long, goes through a center hole drilled in the two base circles and acts as the azimuth bearing. The 33 RMP record goes on the bottom of the top base circle, and three large magic sliders at 120 degree angles are attached to the bottom base circle just inside the diameter of the record. The record sliding on the magic sliders provides a very smooth motion in azimuth. I cut a 45-degree notch at the top of each sideboard for the altitude bearings to ride in... at first, I was going to cut half-circles in the sideboards for these bearings, but with nothing more than a jigsaw, cutting circles was HARD! I had already cut circles for the mirror cell and tube rings, and frankly I didn't want to cut any more circles by hand. The notches have worked out well, but if you have a router and circle jig, I'd go with circles. You can see in the side view how the tube in its rings, with the altitude bearings attached to the sides of the rings, rides in the mount. The planning was all done, it was time to get started building...
Questions? Comments? E-mail me! lefevre@midway.com
(all pages copyright 1999, Paul LeFevre. No text or images from this site may be used without permission.)