Build Your Own Projector

This article contains images, videos, and an interview with my friend Josh detailing the construction of his own home theater projector. The intent of the article is to show you just how easy it is to build your own projector. Please share your experiences by leaving a comment.

This article is aimed at anyone that is interested in creating their own front projection home movie theater for 200 bucks or less. If you haven’t read the projector articles at Tom’s Hardware Guide, you’ll want to start there. If you have read those articles, this article serves as a reinforcement of just how cool and easy this project is, while hopefully presenting some additional information that you will find useful.

The projected image goes from floor to ceiling, which in this case is 8 feet high by 8 feet wide.

When THG published an article on how to build a XGA LCD projector last year, I was very excited. As production of LCD monitors has increased, prices have decreased. 14” and 15” LCD panels that were once considered valuable are now passé. These antiquated monitors however, are reborn as the guts behind a living room movie theater screen on the cheap. The most expensive piece of this project is the LCD monitor, the other piece is the overhead transparency projector which are the ones you’ve seen in school. You might be able to find one for free if you ask around enough, otherwise they can be found on eBay for 50-75 USD. The only intimidating part of this project is disassembling the LCD panel from its housing. That is, until I found out firsthand just how easy it actually was.

Why build my own projector?

Modern projectors from vendors like InFocus, NEC, Viewsonic, or Sony start at 800 USD and increase dramatically as the resolution, brightness, and contrast ratio increase. The thought of building my own projector from 200 USD in parts was very appealing. As the THG article pointed out, buying a 14” or 15” LCD monitor will start you out at an XGA (1024×768 pixels) resolution, where low-end professional projectors (800-1500 USD) start at SVGA resolution (800×600 pixels) which is not sufficient for HD content.

The Media Center PC connected to the projector gives you the option of DVDs, DIVX, games, or other content types.

What am I missing by building my own?

Projectors that cost 2000 USD have very high brightness levels powered by expensive bulbs, making them useful even with the lights in the room flipped on. The contrast ratios far exceed what can be accomplished with a DIY home projector. The bulb in a overhead transparency projector does not produce an image that is nearly as bright, meaning you are really only going to be able to use this with the lights off, and you will likely need to rely on some additional brightness controls through software or maximize the image quality with a dedicated screen. Second, although inexpensive by comparison to modern projectors, most people can not afford to buy and later destroy a 150 dollar LCD. This is where this article and interview come in, I want to show you just how easy and inexpensive it really is to build your own XGA projector.

The LCD panel is removed from its housing and laid on top of the overhead projector. The most difficult part is removing the LCD panel, but once that is done, your home projector is basically ready.

Where do I start?

There are a couple schools of thought associated with this project. On one hand, spending a small amount of time on this project means you will have more time to enjoy it and not be tempted to put more money into it. On the other hand, if aesthetics or image quality are important to you, the sky is the limit as to how fancy of an enclosure you can create, how silent you can make the projector, or how you can maximize the image quality. If you find that the noise the overhead projector emits is too annoying, you can replace the fans. You might be better off just building your own enclosure however, and replacing the stock fan with something like a couple 120mm computer case fans. If you want to improve the image quality, you will want to start with something that reflects more light, like a white screen or maybe a sheet pulled taut. Searching on the internet will yield results on how to improve the image quality from your homebrew projector. LCD panel with projector LCD panel and housing

Josh, a University of Minnesota Computer Science student, took the “quick-and-dirty” approach. Read the interview for details.

Interview

Andy: Hi Josh. I’ll get started with the questions. How noisy is your setup?
Josh: Well, if you have 400 watt speakers hooked up to it, it really doesn’t matter, but if you have the volume down, you can hear it a little bit.

Andy: How much space does your total setup take up?
Josh: It’s in a storage bin about 1 foot wide by a little over 2 feet deep.

Andy: How wide of a room would you say you need to get a good picture?
Josh: Well our room is exactly 14 feet, so the distance from the projector to the wall is probably around 12-13 feet.

Andy: …and that gives you a 8 foot image?
Josh:…yeah, an 8 foot by 8 foot image.

Andy: If you had a deeper room, the image would increase in size as you move the projector back. So I guess you could get an image as big as you want?
Josh: Pretty much.

Andy: How much money did you spend putting it together?
Josh:…a little over 200 dollars. The LCD was about 130 shipped, and the projector was about 75 shipped. Overhead Projector: Apollo AI-1000 from eBay, Monitor: Samsung 152N SynchMaster Flat Panel from eBay

Andy: How much time did you spend?
Josh: Umm, total probably like between an hour and 2 hours to get the LCD apart, then another 2 hours to get it mounted.

Andy: Really? So it took you just 4 hours to get it running?
Josh: Well you can see it’s obviously kinda ghetto-rigged, but yeah…I just wanted to get it running.

Andy: Were there any special tools you needed?
Josh: Uhh, I had to buy a mini set of screwdrivers to get that [the LCD monitor] apart. You need some double stick tape to secure the LCD to the mounts. I used like inch thick mounts to set the LCD on the projector.

Andy: So basically when you took apart the panel and laid it on the projector, it worked immediately?
Josh: Right. I hooked up a VGA cable and booted up a computer. All we had to do was adjust the resolution.

Andy: So really the most difficult part was getting the LCD panel out?
Josh: Yeah. And I thought you’d have to be real gentle, but there were some parts where you had to do a lot of prying, you have to really pry it apart.

Andy: Do you think a putty knife would be a good idea?
Josh: Like a putty knife or a flat head screwdriver, yeah.

Andy: Is the LCD panel itself solid? Bendable?
Josh: No, it feels like a really thin piece of glass. If you just treat it like that [a piece of glass] you won’t mess it up.

Andy: And you did read the guides at Tom’s Hardware?
Josh: You know, I read it one or two times…and I didn’t even look at it when I was actually doing it.

Andy: It’s really that straightforward? Sounds like [setting it up] it’s obvious once you get the LCD panel out.
Josh: It is. Every monitor is a little different, and that is one of the challenges.

Andy: But they [THG] kinda took care of that part for you though, right?
Josh: Yeah, in part 2 they list the monitors that are useable.

Andy: Did the guide mention anything about the overhead projector?
Josh: No. Obviously you want at least 4000 lumens. I don’t know how many lumens are on my projector, but I know it is a 600 watt bulb. Lumens are key when you buy the projector.

Andy: Anything else?
Josh: Cooling is really important. I have my room fan over it. We get a little brown spot on the image, but it goes away.

Andy: So does the brown spot fade in then?
Josh: It comes in probably like 5 minutes after you start it up. All the light heats it up. As long as the light is on, the spot is there.

Andy: So what do you want to add now…if money was no object?
Josh: It’s all about how much time you put into it. I mean obviously I didn’t put much time into it and it’s still amazing…it still functions just fine. Now that we’ve got the brightness figured out [adjusting it through the NvDVD software] I don’t think there is anything pressing to fix on it. It would be nice to have it sturdier. If I want to change the bulb on it, I will have to take it apart. It would be nice to have a nice box for it

Andy: Well Josh, I’d like to thank you for coming out today.
Josh: Well Andy, thank you for coming. I think this has been a positive experience for both of us [laughing].