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Disclaimer: All the how-to directions below are for information only. They are not intended to be sold or used for unlawful purposes. The author takes no responsibility if they cause the reader bodily harm, loss of life, or cause the damage of any property, person, dog, cat, or any other animal. They are presented for information only and all liability is on the part of the reader.
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Building a Better Solar Finder
By Larry Alvarez
Purpose:
The purpose of this how-to is to demonstrate the building of a solar find. This will help you locate the Sun when using a telescope. Finding the Sun sounds easy enough but when you actually try to do it, its not so easy. There are several methods but a simple finder is always easiest for me. The finder uses pinhole projection and some simple parts and costs around 30$.
Understanding the basics:
You need some basic knowledge of cutting glass and using power tools to complete this project. Its not too difficult but it will take some patience and finesse to work some of the pieces.
Parts lists:
Square aluminum tube 5/8 x 5/8 - 14$
Flat black spray paint - .99$
Small piece of wood 1/2" thick
Drill
Glass breaking pliers
Hacksaw
Miter box
Small drill bit and cone shaped drill bit
Frosted glass - 5$ on ebay
Silicon rubber cement - 2$
How To:
Start by measuring and marking the Square aluminum tube. In my case I made it around 2.5" to match the clam shell on my scope.
Use the hacksaw and miter box to cut the tube at the correct area. The miter box will help keep the cut straight. If you've got a good eye you can do this without the miter box.
Next, you'll want to sand the edges on both sides to make them smooth and bur free. I put beveled edges on mine to give it a more finished look.
Use a ruler or tape measure to measure the inside of the tube. In this case its 5/8" x 5/8". We will need this to accurately cut the glass and front waveguide for the finder.
Draw a square on the wood piece the same size as the inside of the tube. Put an X that runs from corner to corner. The middle of X will be the location of our pinhole and a guide for the cone shaped drill bit. Use the small drill bit to make the pinhole all the way through the wood. Then use the cone shaped drill bit to burrow down but don't go to far or you'll crack the corner and have to start over like I did.
The cone shaped bit went down too far in this image.
I had to redraw another square and repeat the process.
After you get a good square with a pinhole and a cone leading to the pinhole check its fit inside the tube. It should be snug but still moveable. You can sand it down if its too tight to make it fit better.
Next we want to cut the frosted glass. This is a delicate process and one that requires leather gloves to be safe. Start by laying the glass on a hard flat surface. I used a flat piece of wood. Next measure and draw out a line across the glass in one direction and then do the same in the other so that the axis makes the need size square for the back of the finder. It would be a good idea to also draw out a backup square.
When scoring the glass. Hold it down with one hand while scoring with the other. Its a good idea to use a guide board to help keep the scoring pen straight when going across the glass.
When the scores have been made grab the edge of the glass with the glass pliers and crack the glass. If the glass is scored well it will crack down the line. If not it will go willy nilly across the surface and you'll have to redraw and try again. Below was my 3 try at it and I was able to make 3 good cracks. Check the fit of the glass in the tube to make sure it fits. If not redraw and recrack.
At this point we need to examine what and where we want to mount the finder. I have a Televue 76 scope that I want to mount it to. There are two threaded holes on the clam shell that take an m5-.8x16 screw. I bought 2 at home depot for 1.29$.
Drill two large holes on the bottom of the finder and two smaller ones on the top. The small ones should be big enough to fit a small screwdriver in to tighten the screws. After the holes are drilled it would be nice to paint the finder to match the scope. In my case it will be flat black.
When the paint has dried take the screws and check the fit of the finder on the scope. After checking the fit take the tube of the finder and put the screws in it so that they stick out the bottom. Once this is complete you may want to put some tape on the ends of them to keep them from falling back into the tube. Place a bead of silicon on the inside of the rear portion of the tube and put the frosted glass in place. The silicon should only touch the edges of the glass so don't apply too much to the inside of the tube. Next do the same for the front and place the wood piece in place. When the silicon cures remove the tape from the screws and mount the finder.
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