Homemade AR telescope
Posted: Mon Apr 22, 2013 2:19 pm
Hi everyone
I really don’t know how to put this in front of all of you.
I have been witnessing so many discussions on the forum regarding AR telescopes, but was not sure whether to buy one for my rifle(Canon LG 150 22 cal) or not and moreover my AR was minus the rails as you could see in the pictures.
Some days back, I just thought of making one for myself. I recollected all the information gathered during my school days. “Optics” was a chapter of Physics course in class x. I remember there were few projects given at the end of the chapter and how to make a telescope was one of them.
I remember that the fore lens (objective) was convex ( + sign ) and the hind lens (eye piece) was concave (- sign).
I wear specs with – power and the power is -3.5 D . I had few old lenses lying with me. I went to an optician and asked for some old lenses with + power. He gave me few old lenses for rs 10.00 . I came back and made pairs of both the + power lenses and the – power lenses and found that some of them were in coordination, that is, I was getting en enlarged, vertical and virtual image. The next problem was to find holders to fix the rectangular lenses. I used a Pepsi bottle cap for the hind lense and a Listerine( mouth wash) bottle cap for the fore lens. But before doing so, I had to see whether the diameter of the both the caps were more than the width of the lenses. Then I went back to the same optician and asked him to reshape the lens as per the new dimensions.
Meanwhile , I went to the market and bought 2 plastic pipes of ½ “ dia and ¾” dia, one foot each( rs 13 for both). These pipes could easily slide into each other.
Once I had acquired all the constituent s, I decide to assemble the telescope.
The main problem was to make holes in the bottle caps, so that the pipes could be put in . I took an iron pipe( ½ “) and put it on the gas stove till it became red . Then I inserted the pipe in the bottle caps and with a little bit of twisting and turning, the holes were ready . I, then inserted the plastic pipes in the holes and sealed the joints with feviquick.
After this , I fixed the lenses on both ends , again with the help of feviquick( the + lens on the bigger bottle cap). After this, I slided the pipes inside each other and judged the magnification and the clarity of the image thus formed. The image was distorted. I had to cut the ½ “ pipe a bit to get the exact length and a clear image and to my joy the image was about 4- 5 times the size of the object and quite clear. My telescope was ready.
The problem I faced after that was the ½ “ pipe kept sliding out of the ¾” pipe. To solve this ,I made a small hole, at the rear end of the ¾”pipe, with the help of a compass, fastened it with a gear ,which was of my old mixer juicer grinder. Now both the pipes were held firmly with the help of this gear. It also acted as the main pivot, to increase or decrease the size of the telescope .
I did all this with no idea about the focal length of the lenses and size of the plastic pipes. It was just trial and error method.
But now the main question was how to mount it on the AR. At the rear end of the telescope I fixed a plastic nut ( with feviquick), and at the fore end I fixed 2 moveable iron clamps – U shaped ( available at any electric goods store). The plastic nut went in perfectly, in the peep sight assembly, and the U shape clamps , held the spring chamber and the telescope, as you could see in the picture.
My experiment came to an end. The assembly is crude, though, it is not sophisticated but still it but works.
The entire exercise was for about 30- 40 rupees, but the outcome was precious.
I sincerely thank you Mr Sharma (my Physics teacher in cl x).
It is working perfectly. I did try a few shots with the telescope on and most of them were bulls eye.
I wish to have your comments.
Enjoying viewing and Regards…….
I really don’t know how to put this in front of all of you.
I have been witnessing so many discussions on the forum regarding AR telescopes, but was not sure whether to buy one for my rifle(Canon LG 150 22 cal) or not and moreover my AR was minus the rails as you could see in the pictures.
Some days back, I just thought of making one for myself. I recollected all the information gathered during my school days. “Optics” was a chapter of Physics course in class x. I remember there were few projects given at the end of the chapter and how to make a telescope was one of them.
I remember that the fore lens (objective) was convex ( + sign ) and the hind lens (eye piece) was concave (- sign).
I wear specs with – power and the power is -3.5 D . I had few old lenses lying with me. I went to an optician and asked for some old lenses with + power. He gave me few old lenses for rs 10.00 . I came back and made pairs of both the + power lenses and the – power lenses and found that some of them were in coordination, that is, I was getting en enlarged, vertical and virtual image. The next problem was to find holders to fix the rectangular lenses. I used a Pepsi bottle cap for the hind lense and a Listerine( mouth wash) bottle cap for the fore lens. But before doing so, I had to see whether the diameter of the both the caps were more than the width of the lenses. Then I went back to the same optician and asked him to reshape the lens as per the new dimensions.
Meanwhile , I went to the market and bought 2 plastic pipes of ½ “ dia and ¾” dia, one foot each( rs 13 for both). These pipes could easily slide into each other.
Once I had acquired all the constituent s, I decide to assemble the telescope.
The main problem was to make holes in the bottle caps, so that the pipes could be put in . I took an iron pipe( ½ “) and put it on the gas stove till it became red . Then I inserted the pipe in the bottle caps and with a little bit of twisting and turning, the holes were ready . I, then inserted the plastic pipes in the holes and sealed the joints with feviquick.
After this , I fixed the lenses on both ends , again with the help of feviquick( the + lens on the bigger bottle cap). After this, I slided the pipes inside each other and judged the magnification and the clarity of the image thus formed. The image was distorted. I had to cut the ½ “ pipe a bit to get the exact length and a clear image and to my joy the image was about 4- 5 times the size of the object and quite clear. My telescope was ready.
The problem I faced after that was the ½ “ pipe kept sliding out of the ¾” pipe. To solve this ,I made a small hole, at the rear end of the ¾”pipe, with the help of a compass, fastened it with a gear ,which was of my old mixer juicer grinder. Now both the pipes were held firmly with the help of this gear. It also acted as the main pivot, to increase or decrease the size of the telescope .
I did all this with no idea about the focal length of the lenses and size of the plastic pipes. It was just trial and error method.
But now the main question was how to mount it on the AR. At the rear end of the telescope I fixed a plastic nut ( with feviquick), and at the fore end I fixed 2 moveable iron clamps – U shaped ( available at any electric goods store). The plastic nut went in perfectly, in the peep sight assembly, and the U shape clamps , held the spring chamber and the telescope, as you could see in the picture.
My experiment came to an end. The assembly is crude, though, it is not sophisticated but still it but works.
The entire exercise was for about 30- 40 rupees, but the outcome was precious.
I sincerely thank you Mr Sharma (my Physics teacher in cl x).
It is working perfectly. I did try a few shots with the telescope on and most of them were bulls eye.
I wish to have your comments.
Enjoying viewing and Regards…….
, you have dared to venture where few think. Kudos to you.