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Homemade red dot sight???

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Homemade red dot sight???

Unread postAuthor: The_Kangsta » Tue Apr 01, 2008 12:40 am

Has anyone here ever made their own red dot sight or understands exactly how they work?

Because im not allowed to go to Wal-mart or some place and get one, plus, making one homemade is probably cheaper.

I have a general understanding of the red dott sight, where the led projects the dot in front of the objective lens. Any suggestions? [/b]
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Unread postAuthor: boilingleadbath » Tue Apr 01, 2008 3:48 pm

Well, for an actual red-dot optic, you'd need a specially curved surface. I don't know what this surface curve is, so I don't know how available it would be, but you'll be paying 10$ shipping on (unless you find a suitable surplus lenses) a 20$+ piece of glass.

However, 1x fixed-power scopes are easy to construct: place 3 identical lenses in a row, each space being 2 times the focal length of the lens. Put the aiming point halfway between one of the pairs of lenses.
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Unread postAuthor: Solar » Tue Apr 01, 2008 9:36 pm

Do this. Take a red led and encase it so only the very tip has a little hole (pin sized) out the top. Take a piece of say... 1.5" pvc and find a piece of round clear acrylic or polycarbonate. Poke a hole in the bottom of the tube and work the led to angle into the tube. Put a cap end on the pvc tube and trap the acrylic in between and make sure you have a bit of an angle to it. The idea is for the led light to reflect back at your eye off the acrylic. Takes a bit to center things up, but I made one about 20 years ago this way. Cheaper, but kind of a bit of work. Since you can find cheap red dots for twenty dollars, makes it kinda silly, but you cvan make BIG ones this way. Also fun to experiment. Oh...yeah... you need to power the LED with a battery. Remember that LED's are uni directional and it makes a difference if you have the polarity reversed.

Good luck, let me know if you have any improvements or advice. I think I might have used a couple pieces of acrylic just for the heck of it, but don't think I needed to.
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Unread postAuthor: D_Hall » Tue Apr 01, 2008 9:57 pm

The lenses used in red dot scopes are hyperbolic in shape. Not exactly something you're going to run across in any other application.

Make your own? A *real* one that actually works like they're supposed to? For less than you can buy one? ROTFLMAO. Dream on.
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Unread postAuthor: jackssmirkingrevenge » Wed Apr 02, 2008 1:06 am

It's easier to figure out a way to buy/borrow/steal and existing model.
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Unread postAuthor: Tom » Wed Apr 02, 2008 1:38 am

I would steal one :D . Just like said above you would be better of buying one.
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Unread postAuthor: boilingleadbath » Wed Apr 02, 2008 3:16 pm

OTOH, a 1x scope with illuminated reticle could be made for 5$.

Yeah, at that price range the lenses would almost certainly be plastic... not much we can do about that.

While you are making your own reticle, you might as well put fall-adjustment marks at the proper points. There are any number of ways to do this - the easiest is to print out the reticle on a piece of transparency (as they use for overhead projectors). Remember, 1" on the reticle per 1000" of lens focal length equals one miliradian on the field-of-view.

Alternatively, use a number of pieces of copper wire as the reticle. Bend them into position to zero the scope.
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Unread postAuthor: Counterstriker » Wed Apr 02, 2008 3:24 pm

Making one would be hell.. why not buy one there pretty cheap, Try Hotspotairsoft.com
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Unread postAuthor: scottcrete » Wed Apr 02, 2008 3:49 pm

lol............ this is the funniest one so far.. WEEEEEEEEEEEEEEE im drunk...
or is this funny to other people too?
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Unread postAuthor: jackssmirkingrevenge » Wed Apr 02, 2008 4:28 pm

scottcrete wrote:lol............ this is the funniest one so far.. WEEEEEEEEEEEEEEE im drunk...
or is this funny to other people too?


We call this PUI or "posting under the influence", and like many things done while inebriated, it's usually regretted the next morning.
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