Build a projector out of a tv for cheap!

[IronOxide]

I don't know if many people know about this, probably most people choose not to do it, but I think it's kind of a neat thing to try if your circumstances are close to mine. I want to warn you if you are reading this that it is not as clear of a screen as a lcd projector, but you can build this with $15 if you really wanted to. If you would like to have a huge screen and don't have much money then this is an option. The room you put it in has to be extremely dark. I got this from an aution on ebay similar to this one. Basically what you do is get cardboard and form it around the tv and have the light shoot through a fresnel lens (basically a magnification sheet). You form a box inside a box with so that you can move the lens back and forth to focus. I actually built a screen out of a 4'x8' board painted white that I use to watch wide screen movies, and it works great. You can get the fresnel lens pretty cheap (the $2 one half way down) if you find a company not marketing them as a big screen. And by the way, if you want to do this you a few options, because once the light goes through the lens it gets reversed and up side down. If you want to set your tv upside down (not the smartest thing in the world) then the images would just be reversed, kinda silly, but works. What I did was open up my tv and cut the wires controlling the vertical and horizontal and switch them. It's pretty easy to do, but kinda dangerous. I've actually found a few websites that give some instructions such as this one, this one, and this one.

Remember! If you are magnifying a 13" tv such as I am, then the bigger you get it, the blurrier it'll get. Please don't flame me if you don't want to build one, it's not for everyone. It takes quite a bit of time to do, but it costs hardly anything and is fun! Good luck if you decide to do it!

 

[clarkmo]

Glad you were able to get it to work.

 

[forkd]

I will probably not do it but I appreciate knowing that it can be done. Thanks

 

[IronOxide]

I figured some other poor college students would like to try it. It's really not that hard, and it's fun. I've watched a movie almost every day! It's cool!

 

[DurocShark]

Nice project... I wonder how tough it would be to use a larger tv for the source?

 

[conehead433]

Warning! Do not turn your TV upside down, you could easily ruin it. Keep in mind that the resolution of your picture, depending on how large an image you project, will be rather poor. Using a computer setup with a monitor set a high resolution could give better results in regard to picture quality. And you can adjust the reverse and upside down picture with mirrors. They would need to be optical quality and not reflect from the back side of the mirror. OK so for those of you who have time to waste and want to do this, here's a site with step by step instructions.

Build A Projector (PDF)

Projector Info

 

[alan121]

thanks for the info. So joack@ss on eBay was selling this thing for $12.95.

 

[codeyf]

Is this kind of like what you're talking about?

 

[whizbang]

Cool reminds me of the submarine I built from plans advertised in the back of my comics when I was a kid. Oh, and the xray specs. Awesome!

 

[bleuiko]

Originally posted by: whizbang
Cool reminds me of the submarine I built from plans advertised in the back of my comics when I was a kid. Oh, and the xray specs. Awesome!

Were you listening to the radio yesterday night by any chance?

 

[IronOxide]

Originally posted by: codeyf
Is this kind of like what you're talking about?

Ya pretty much, just you don't have to buy their instructions because info is always free somewhere! conehead433 that's a pretty nice page, and remember everyone if you are going to do this paint the inside and outside of the cardboard box flat matte black!!

 

[FearoftheNight]

is it hard to do? i may just try this...iron how big of an image do you expand it to from ur 13 in?

 

[conehead433]

"You've got to understand stupidity and make it work for you." - Zappa

This is funny. It's all over the net. Some are selling movie projector kits for $30 or so, and some are selling just the lenses for that much. Some claim that the picture is as good as HDTV projection sets. You can buy an 8 1/2 X 11 page magnifier at Staples or Office Depot for about $9 or you can find fresnel lenses at a number of websites for cheap. Shipping costs sort of elimate the savings unless you are ordering a few. And you are not going to get 1080 res on your wall or projector screen using this method.

 

[conehead433]

"Cool reminds me of the submarine I built from plans advertised in the back of my comics when I was a kid. Oh, and the xray specs. Awesome!"

Have you got plans for the submarine or the X-Ray specs? I was thinking I could put me up a little website selling those and see how much money I can make.

 

[conehead433]

"is it hard to do? i may just try this...iron how big of an image do you expand it to from ur 13 in?"

You can make it any size you want by changing the distance from your wall or screen. The larger you make it the worse the resolution will be. But if you're drunk out of your mind at a frat party or something watching Animal House or whatever, I doubt that you will notice.

 

[IronOxide]

Originally posted by: FearoftheNight
is it hard to do? i may just try this...iron how big of an image do you expand it to from ur 13 in?

I took me about 3 days to set up. But only because I made a huge screen and everything. I'd say it's definetely worth doing. I'm blowing it up probably a little too big, but it depends on how far back from your screen the tv is. I wanted it to be at the back of my room which is 10ft. I haven't measured how big the screen is in a normal 4:3 ratio, but in the 16:9 I'm pushin' 107" which means it's freakin huge in 4:3. if you stay under 100" it'll probably look really good. Btw I played super smash brothers on 64 on it. It was a blast!

 

[Jugernot]

I have a hard time beleiving you can get a useable picture out of a 13" TV tube... that is putting MAYBE 150 lumens at most. I'd have to see a picture to believe it.

 

[IronOxide]

Originally posted by: Jugernot
I have a hard time beleiving you can get a useable picture out of a 13" TV tube... that is putting MAYBE 150 lumens at most. I'd have to see a picture to believe it.

Dude, I said 'The room you put it in has to be extremely dark. ' I wasn't kidding, it works, I did it, I like it.

 

[ObiDon]

Originally posted by: Jugernot
I have a hard time beleiving you can get a useable picture out of a 13" TV tube... that is putting MAYBE 150 lumens at most. I'd have to see a picture to believe it.

Back in the good old days (?) LCD projectors were putting out 200-250 lumens. And, that was on the higher end.

 

[DavidinCT]

I tried this in a Dark room with out building a box. My setup for this is a SVGA monitor, Hooked up with a HD DSS box that has a VGA out, only using for HD local channels (has a HD tuner in it). Under my test. It looked Awsome in true 1080i with a 15" computer monitor. The problem is it's reversed and upside down.

I wonder..is there a way on a 15 pin VGA cable to be able to reverse and make the picture upside down ??

PM me if you know..

Over all, if you can get over that one thing, it would give you a 8 ft screen (as long as the room is very, very dark, not good for your living room with a lot of windows) and cost you only about $25 if you want to build it out of wood and not cardbord. Heck, 8 ft screen for $20ish, Dam, now that's a good deal, and if you get one of those HD boxes that has a VGA output (older models should be no more than a few hundred), you could have true HD on a 8 ft screen for $300-400...

You can buy the lens on ebay for $3-6 if all else fails..

 

[IronOxide]

It would be nice to figure out how to make a dual lens system like this. That would rock, it wouldn't be reversed and upside down

 

[erickotz]

Originally posted by: conehead433
Warning! Do not turn your TV upside down, you could easily ruin it. Keep in mind that the resolution of your picture, depending on how large an image you project, will be rather poor. Using a computer setup with a monitor set a high resolution could give better results in regard to picture quality. And you can adjust the reverse and upside down picture with mirrors. They would need to be optical quality and not reflect from the back side of the mirror. OK so for those of you who have time to waste and want to do this, here's a site with step by step instructions.

Build A Projector (PDF)

Projector Info

Standard Direct view (non-projection) TV's don't care which side is up-with the possible exception of heat buildup, so having a fan might be useful. Projection TV's should never be lied down or turned over, but I would like to see someone try and turn one over.

The problem with a computer monitor is that it is higher resolution. Higher resolution = lower light output. Personally, I'd reccomend a used LCD projector. That's what I went with and we had fun projecting on walls in my college dorm last year. Also relatively easy to transport.

 

[IronOxide]

Originally posted by: erickotz

Originally posted by: conehead433
Warning! Do not turn your TV upside down, you could easily ruin it. Keep in mind that the resolution of your picture, depending on how large an image you project, will be rather poor. Using a computer setup with a monitor set a high resolution could give better results in regard to picture quality. And you can adjust the reverse and upside down picture with mirrors. They would need to be optical quality and not reflect from the back side of the mirror. OK so for those of you who have time to waste and want to do this, here's a site with step by step instructions.

Build A Projector (PDF)

Projector Info

Standard Direct view (non-projection) TV's don't care which side is up-with the possible exception of heat buildup, so having a fan might be useful. Projection TV's should never be lied down or turned over, but I would like to see someone try and turn one over.

The problem with a computer monitor is that it is higher resolution. Higher resolution = lower light output. Personally, I'd reccomend a used LCD projector. That's what I went with and we had fun projecting on walls in my college dorm last year. Also relatively easy to transport.

Every tv I tried to turn over for this project would turn a purplish color. You can't tell me that that's good, or even ok for a tv. I liked the whole opening the tv and cutting the wires idea. It was really simple, and I don't have to watch people drive on the wrong side of the road like the crazy europeans!

 

[pete777]

try better quality projects at www.diyaudio.com them go the forum and video

 

[ObiDon]

Originally posted by: IronOxide
It would be nice to figure out how to make a dual lens system like this. That would rock, it wouldn't be reversed and upside down

With nVidia-based cards you can just use NVrotate (180 degrees) to fix that problem. It's somewhere in the drivers.

I don't know if ATI has anything similar...