YOUR Telescope

Mount SAC Astronomy students. You can easily make your own telescope! It will give beautiful views of the Moon's craters, the phases of Venus and the moons of Jupiter. It can do everything that Galileo's telescope did.

Unlike most astronomical telescopes, with this one the picture is right-side-up. So it also works well for bringing birds and distant wildlife up close.

I made the telescope you see above. With it, I see Saturn's rings, but they look really really small. Don't get your expectations TOO high.

I took this picture of the moon with my cell phone attached to the telescope. Waxing crescent Moon taken through the telescope

Parts list

  1. Eyepiece with erector prism taken from a pair of binoculars. $7.86
  2. Objective lens $8.00 (Shipping is $6.00)
  3. Pipe, PVC 1 1/4 inch inside diameter, for the telescope tube. $3.40
  4. Dewcap is made from a PVC pipe coupling. $0.86
  5. Flat black spray paint. $3.98
  6. Masking tape. $2.48
  7. Camera tripod. (I already had one.)

Total spent: $30.58 (Includes shipping, but not tax.)

Where to buy the parts

Eyepiece with prism. These come from a pair of Ozark Trail 8x21 Binoculars, $7.86 here:Walmart Ozark Trail 8x21 Binoculars.

Objective lens. Ordered online from Surplus Shed, www.surplusshed.com, $8 here: 27MM DIA OBJECTIVE IN BRASS CELL 285MM FL. (Shipping is $6.00)

Telescope Tube. This is a piece of PVC pipe, 1 1/4 inch "schedule 40" from Home Depot, store SKU #987414, $3.40 here: Charlotte Pipe 1-1/4 in. x 2 ft. PVC Sch. 40 Pipe. I cut it to a length of 25 cm (9.8 inches). This length will be OK if you use the objective lens and eyepiece specified above. If you use other lenses then you can determine the right length as described in my video.

Dewcap. This is a PVC pipe coupling for 1 1/4 PVC pipe from Home Depot, Store SKU #293989, $0.86 here: Charlotte Pipe 1-1/4 in. PVC Sch. 40 S x S Coupling.

Flat Black Spray Paint. This is needed to stop reflections inside the telescope tube and dewcap. I used Rust-Oleum Painter's Touch Flat Black, store SKU #621138, $3.98 here: Rust-Oleum Painter's Touch 2X 12 oz. Flat Black General Purpose Spray Paint.

Masking Tape. Tape is wrapped around the eyepiece and objective lens to make them fit inside the telescope tube. I used 1 inch wide tape, but next time I want to use wider (2 inch?) tape on the eyepiece and narrower (3/4 inch?) tape on the objective. Anyhow, the tape I did use is from Home Depot, store SKU #690187, $2.48 here: 3M Scotch 0.94 in. x 60.1 yds. Contractor Grade Masking Tape.

Camera Tripod. You need some way to hold the telescope steady and a tripod works well. Check Walmart. You could try this: Search Walmart for tripods.

Tools

  1. Small, flat blade screwdriver. 3 mm wide is good. Needed to take apart the binoculars.
  2. Sharp knife. Needed to remove rubber from binoculars.
  3. Hacksaw with blade for cutting metal. Needed to cut off an aluminum "bump" on the binocular tube that will be used as the eyepiece. (See video.)
  4. Vise or table clamp. Needed to hold the binocular tube as you are cutting it. You could use a kind volunteer to hold it, but make sure they are wearing gloves to protect their hands.
  5. Files. Needed to file down the aluminum tube.
  6. PVC cutter. I used a miter saw because it makes perfect 90 degree cuts.
  7. Sandpaper. Coarse and fine for cleaning the pipe and removing sharp edges.
  8. Acetone. Technically this is not a tool, but it is very useful for cleaning up spray paint. (Note: Home Depot might not sell Acetone without I.D.) Be careful! Acetone melts certain plastics.
  9. Alcohol. Useful for removing fingerprints from lens surfaces. (Don't use acetone for cleaning lenses.)
  10. 1/4-20 tap and No.7 (or 3/16") drill bit for making the threaded hole the camera tripod holds on to. I had my own already but you can get it at Home Depot, Drill America 1/4 in. -20 High Speed Steel Tap and #7 Drill Bit Set (2-Piece)
  11. Drill. I used a battery-powered drill which can spin slowly for making the 1/4-20 thread.

Construction

Please look at my telescope construction video on YouTube.

Study this Facebook page that has the original design, the STEM Spyglasses for Puerto Rico.

I want to credit the article The STEM Spyglass Project. How to make a small, very inexpensive refractor. by Jerry Oltion in Sky and Telescope magazine, July 2020.

Peter Halverson 9/2020

phalverson@mtsac.edu

pghalverson@gmail.com