BEST DIY Simple Reflex Sight

Intro: BEST DIY Simple Reflex Sight

All you need is a CD case, and you get a perfect circular aiming dot :)
Have fun making!

STEP 1: Tools and Material

All you need is:

- small saw

- glue

- dremel tool (a hot nail can poke a hole in that too)

- old CD case (maybe 2)

- 3V button cell

- LED (blue LEDs run on 3V, so no other parts needed!)

- pair of pliers or something 90°angled to bend the main part, plus lighter

STEP 2: Step by Step Video

THE STEPS:

1. Print and cut out the template (cardboard will work best, paper is too thin)

2. Place it on the clear CD cover, and grab a marker

3. Works best with a small saw: Cutting it out

4. Mark a stripe of 4cm in the center

5. Use a pair of pliers and a lighter to bend it by 90° on each side

6. Cut out 2 L-shaped edges (from another clear CD case lid)

7. Glue them onto the first part.

8. Make the 4 cm wide, 9 cm long centerplate (same clear plastic) and glue it on the L-pieces

9. Grab the black disc-holding part cut out a piece as shown in the video and glue it to the rear

10. Make 2 side plates, and glue them on

11. Glue in a tiny L-plate to make sure, the battery is held in place, same for the LED

12. Glue on a stripe of the clear stuff to cover the LED and battery

13. Time for paint, tape off the exit hole and rear section...then cover it in black, 2-3 layers.

14. Glue in the display and done :)

Comments

[ptkrf]

Real reflex sights have curved screen...

[Esque]

Not necessarily, I shot field target rifle for years, none of the reflex sights I ever used were curved.

[jjsorensen]

This is sorta true. We had EOTech sights on our M4s in Iraq. The "reflection" surface was flat. It is not a reflection though. It is a hologram made specifically to put the dot at the correct position for your viewing angle. Wiki: reflex sight (lenses) and holographic sight. There's quite a price difference.

It makes quick sighting very easy since you just have to put the dot on target. Ours ran about $500 a piece, were anodized aluminum, and were fairly accurate (I wouldn't recommend shooting qualifications at a sharp viewing angle or setting the iron sights off the dot; setting the dot off the iron sights worked fine).

The holograms were lit with a solid-state laser. They have a narrow enough band to make it work (but not narrow enough to create the hologram - probably used HeNe, Ar, or ruby). Regular LEDs are nowhere close to monochromatic so a reflection surface is about as good as you will get - it should be plenty accurate for say a squirt gun, probably could be aimed for narrow angles for BBs, probably a bad option for pellets.

[Deftware]

If the EOTech uses a laser at all I'm sure it uses a laser-diode. HeNe/Ar/Ruby lasers are lab-grade lasers that operate with many watts of power on a tabletop setup.

Thank you for your service!

[ptkrf]

Partially true. EOTech is a whole other story so let's leave it out. laser is best because it only emits one wavelength and is easier to coat reflection surface so that it lets all other wavelengths pass through and use minimal power.

Curved glass only puts the dot at infinite distance so that it is easier to look at target and reticle without eye adaptation.

[ptkrf]

as far as I know curved screen makes dot focus at infinity so cheap ones may have flat screens...

[Esque]

The ones I was using weren't particularly cheap I have to say.

[-Selfmade-]

I dont really think its too bad, because you have to line up with the target, eye wise. Why would it help to look at it from an angle? You cant aim that way anyways...I just wanted to show something cool but simple. I could go crazy and make a real one, but they could not copy it...no matter what you do, they nag about it :p

[ptkrf]

Why would it help to look at it from an angle?

you do realize that looking from an angle is what reflex sights are made for, right? The point is that you don't have to look through scope with eyes aligned as perfectly as with iron sights a.k.a. from an angle

[BillbockD]

And they cost a average of 50$ for standard quality.

This probably cost you what? 5$ if you need to buy all the thing? i think for the difference in price you can live with with an uncurved screen or curve it yourself ;)

[ptkrf]

not my point...
reflex sight / something similar
expensive / cheap
not a real reflex

funny how this comment is getting comments faster than my instructables...

[-Selfmade-]

I own several, and its not just curved. That would only work for the x-axis. Its a coated "lens"...

[-Selfmade-]

Nope, they have sort of e LENS as a screen, because bending it will just work for the horizontal/x axis, not for the vertikal y axis. Ok?
And it says SIMPLE....so come on....really.

[ptkrf]

I don't agree with what you said but... ah well

[-Selfmade-]

Well its the last one you get from me dude....because you seem you dont even understand what I am trying to tell you. Nevermind. Its physics, physics is not for everyone.
Beside that...it says SIMPLE, how can you expect a high end sight? Spend more time MAKING stuff instead of talking about other peoples stuff...another argument you cant beat. Have fun making.

[GarethR5]

Nice job, but what you have made there is a toy, or a prop, it lacks the actual function of a reflex sight, which is parallax correction.

Time spent discussing vs MAKING is well spent if it stops you wasting time making something which doesn't work. It's like "measure twice, cut once".

[-Selfmade-]

Dude.....it says SIMPLE. You are not a maker, so make a better one, same simple material...then you can give it to me :p Or is it jealousy? Because you cant be serious.

[Deftware]

EDIT: (Read your other comments, you're aware that there's optical curvature. I'll leave this for anyone who doesn't understand the difference. )

He's trying to educate you as to what the difference is between what you've made and what a sight that you can actually use for aiming does optically. What you've made can't be "zeroed" to a gun the way a proper red dot optic can - where no matter which angle you're peering through it the red-dot is at optical "infinity". That's to say that when peering through a red-dot sight the apparent position of the red-dot is as though it's at an infinite distance away by using optically-accurate concave curved glass to reflect the illumination source. What you've made will only be accurate if your target is in-front of the CD-case plastic by a distance equal to how far the illumination point is behind it, which is ~2 inches. That means it's worse than iron-sights for actually hitting a target.

Granted, what you've designed for the body of the sight is impressive for being made from a CD-case, very clever use of its different parts, and if you could just get or make a reflector that's curved, and positioned, so that the resulting reflected dot is at optical-infinity then you'd have something that could actually be used on a gun that won't get you killed in a firefight when your bullets aren't flying where you're putting the dot.

I attached an image that diagrams what dude was talking about. If you can figure out how to lightly melt the CD case over something that is shaped exactly as you need (some kind of magnification power might work) and then cut that out to fit your sight encasement, then you'll have something that's even better than iron-sights for aiming. THAT would be even more impressive, because it would actually be useful, rather than only looking neato.

[GarethR5]

I'm not knocking your making, I just don't think a reflex sight CAN be made simply. There's a difference between SIMPLE and NON FUNCTIONAL.

I don't have any ibles up, but trust me I am a maker, I'm mostly done on a cheap, simple to make, 'Hog Saddle' gun clamp. I may make that into an ible if it turns out well. I also recently made a robotic target setup controlled with an arduino, this one: www.youtube.com/watch?v=xU9IJjv8u4U excuse the video, but you'll get the idea.

[koden88]

Reflex sight can be rather simple, google "telrad reflex sight". It does not use curved glass but regular lens, mirror and flat glass. I bet anybody can make this at home.