I've been flirting with the idea of building a projector for years. I periodically check in here and dig out a little more information, see the amazing builds some of you have done, and learn a little bit more about what's involved. After all this time, I frankly just don't trust myself to build something solid from the ground up like that. I'm a tinkerer but not really a craftsman, and all of the reading I've done tells me there are several key stages where I could (and likely would) damage components that would be expensive to replace. Digging around I found some folks using overhead projectors to do DIY home theater projectors easy and even cheap. This idea seemed perfect for me, something I can handle.

Found this link here at lumenlab in the beginner's forum stickies:

http://www.manhattanlcd.com/product_p/1000.htm

That looks like everything I need on the LCD side, screen and controller. From the official wuxga 1080p guide, it seems I'll still have to strip this some, but it looks a whole heck of a lot easier than stripping a whole monitor. And having the screen paired with a controller when I buy it seems like it saves a big part of the headache there, even if it costs a little more. That screen/controller is $400 plus shipping, but will do true 16:9, 1080 lines rather than 5:4 or 16:10 with 16:9 stretched.

Overhead projectors are all over on eBay, and even brand new they're not that pricey. I haven't selected one but I know I'll be looking for something with two bulb mounts and a switch between them, that uses bulbs that sell at a price I'm willing to pay. Beyond that, the highest lumens I can afford Throw in a little hardware to mount the LCD and any necessary hacking to the OHP, I figure the whole thing is still cheaper than I'd pay for even say a 32" 1080p lcd tv. This will be in a dark room, I'm not concerned too much about brightness. I'm going for biggest 1080p picture for the buck that's watchable in a relatively dark living room. The overheads I'm looking at so far do 1500-2000 lumens for pretty cheap, so I don't think the goal is unattainable.

Anyway, I still have questions and I think whoever's still active on this forum can help.

1) With the LCD panel being smaller than the overhead's bed, I'm assuming I'll want to mask it somehow so light isn't spilling out all over where the panel isn't covering the light source. What would be a suitable material for this? Wood I guess?

2) What about temperature of the OHP's bed? It's been a long time since grade school, but if memory serves you can't pull an item away from the projector bed, or it will get blurry. But resting an LCD on the bed can't possibly be good for it. Would elevating it a couple mm from the bed be okay? Is that enough clearance to do any sort of air cooling with fans? Or should my goal be to see what I can do about improving the cooling inside the overhead's case so the bed gets less hot? Ideas there?

I know this is pretty low tech for this crowd, but any advice is appreciated

-- josh

Hope this helps: Panel + OHP

Hey, thanks. I wasn't quite seeing the point of that link at first, it being in french and just a photo gallery. But I looked them over, saw several things I absolutely won't do, and a few neat ideas. It also looks like a 15.4" widescreen is going to be too big But, the same company sells a 10.1" widescreen w/controller for a little less that'll gimme 720p and be small enough for me to mask it correctly and not have cropping issues. It also looks like some of those guys are getting the screen far enough away from the bed for heat to not be an issue, and I think the 10" screen will give me enough room to mount fans on the mask plate (blowing perpendicular to the bed) and get some airflow into the gap. I think this is gonna work out. It won't get me 1080p, but hey.

Picked out a projector 3M 9550. 4000 lumens, and a triplex lens. 11.5" bed, so I'm definitely going to have to go with the smaller panel from Manhattan LCD. For now, I found a steal on a sharp qa1500 for testing and to use while I'm working on the mount for the pricier panel.

Now I just wait a week for this crap to ship to me :/ :fidget:

Heyjoshdotnet:
Always great to hear from OHP retrofitters!
The smaller panel is definitely the better route. 720 looks good as long as you're careful on how far back you place the overhead. As for the 15 inch panesl, I started out with one from ebay and just made sure I had the same amount "hanging over" on each side. Then I purchased a 12.1, built my own frame to hold it, and it works wonderfully. I too looked at that French site and has a bunch of good ideas, but they all seem to be using, except for a small few, halogen OHP's. I recently purchased a 9850 and it easily smokes my 9800. Be sure to post pics of your mod!

It's been a comedy of delays so far I received the projector, dude only cushioned two sides of the box. It took damage. Cosmetic, though, so I'm living with it. Also, both bulbs were INSTALLED before shipping, and they of course broke. So I had to wait for the guy to send me working bulbs before I could even know what I'm getting into.

Those finally came today, along with the untested as-is ultracheap Sharp QA-1500 I ordered. The panel was a wash, it doesn't recognize any signal from its composite input (menus and everthing display okay though). So the idea of having a big standard definition screen to use while building the mount for the good panel is dead. Oh well More incentive to finish.

I cut a mask of the 10.1" panel I plan to buy, to get an idea of image size:



Just shy of 90", the OHP is just behind my couch. If I orient the room differently, I can get larger. Giggity.

Back to the lab to build the mount for the panel. More updates soon hopefully!

That sux about the 15 in. panel... Does it have a vga imput? My apologies if you answered this already, but it's late and I just logged on...
From your photo, you should have rather even lightness, but I wouldn't go much farther back with your OHP, otherwise you will notice screendoor....
keep at it my friend!

Thanks for the kind words! Things are coming together fast. At least on paper. I sure lit up my credit card. Ordered the screen/controller, laid out the mounting frame plan and bought all necessary parts. I'll get a good weekend to work on it!

Yeah the panel is one from Manhattan LCD, a kit with the 10.1" 16:9 720p panel plus a controller with vga/hdmi/component inputs, and built in control software (IR remote and everything). Definitely not a budget project from the bottom up, but from the top down it's still going to be cheaper than the 40" LCD I *almost* bought at Best Buy for $800 a few weeks ago The OHP is from eBay and now that I've seen these 9850s you mentioned (eleven fracking THOUSAND lumens??), I'm thinking I'll be getting a different one so that will be a double expense. wheeeeee. At least the projectors are sort of cheap

I rearranged the room and went longer, got a 9 foot picture but noticed the screendoor thing you're talking about. I may just live with it for convenience of room arrangement and sheer picture size. I may also be noticing it more now because I have no real video, just the blank white projector bed I'll have to see video up there to really decide.

Hopefully more updates and less-boring pictures after this weekend!

The 9850's are awesome. The replacement bulbs aren't cheap (160 is the cheapest I've found so far) but at 750 average running hours,who cares! It's stupid bright and has good color! You won't regret buying one like it. Metal halide beats halogen hands down for these projects.
Good purchase on the panel! I was toying on getting that one before I settled on the 12.1 mainly for price reasons.

LOL! once you start buying everything you need to make something that's better than a flashlight behind a coloring book it sort of takes the DIY price out of DIY! *credit card catches fire!*
But it's still cheaper than buying a commercial one!
As for the screen-door, you'll really notice it once you start using the panel... I tried putting mine against the opposite side of my living room and the image was huge, but you could totally see the pixels... so I moved it back and all was well again...

Looking forward to seeing your progress... You should grab a couple shots of your projector too

Screen arrived today, and I set down to stripping it. Relatively easy in the end, but there were a few scary moments. Especially pulling the backlight itself off The bottom is held on by adhesive. That part of the job is one of those slow-motion surgical moments that are almost outside of reality.

Before:


During:


After:


Details in blog post: Stripping the 10.1" LCD Panel

Really nifty, the whole thing was framed up in a piece of aluminum:


It's the perfect match for the screen, holds it in place perfectly. Since I don't trust my woodworking skills, I'm having the mounting part of the frame built. At Hobby Lobby of all places. I figure a picture frame is perfect. The recessed part on the back, where you normally stick the glass/photo/backing, if sized for this piece of aluminum, will hold the screen nice and straight.

Planning on getting a thin one, say 1" frame but .5" deep. Then building my own U shaped piece of framing out of some light wood at .5" x .5" (probably be able to get that at Hobby Lobby too), or just use 1x1 from home depot. I figure a U shape where the U is on its side, and have it be wider than the frame. The points of the U would be flush to the picture frame, while the curve of the U would extend over. Then I can use matboard to cover it, put a hole in that and a PC Case fan blowing upward. One side air intake vent, other side fan blowing out. Should keep the air between the panel and the bed plenty cool. I did the math at some point on one of these insomniac nights, and figured I only needed about 3 CFM to cycle all the air inside that frame once per second. A case fan will do more like 20-30. It's less important for that part to be perfectly square, so I figure I can handle it. I used a coping saw once. In high school. I didn't kill anyone with it.

It's taking all the self control I have not to rig something up half-ass tonight just so I can see the picture. Mostly the $330 smackers I dropped on that screen are stopping me. No rigs, no risk. Buying one was stretch enough, I only justified it against the price of a TV I was going to buy anyway. Buying two would be...problematic

I work nights, so I can't hit Hobby Lobby til Saturday. Hopefully more pics then!

Finished! Sorta. Some of it was rushed together because I REALLY wanted to see it in action

Details at: http://heyjosh.net/?p=78

Here's my frame:


And with the fan and screen:


Finished projector (well, not completed. But usable )


Output:


I will definitely be replacing the projector with a brighter one. It's good in the dark (well, watchable), but in any light it gets washed out pretty good. 4000 lumens, through the LCD becomes 400 lumens (approx). Gonna have to get some more light in there

Nice job! I do have a question. It looks like you are running composite on that nice HD panel? You know you will get a lot better results with at least component.

It is component. But when I first was using it, I didn't realize that the cable box was set for 480 lines

I moved my PC to the living room (will use my mac in the office, I only game on my PC anyway). I'm off to kill HUGE zombies in Left 4 Dead.

But first, Eva Longoria:

Now I know why you thought I was using composite. THe cable is a composite+audio set, but I'm using it for component Cables are cables.

I've been up all night watching TV and playing video games. I definitely want a brighter projector, but it's been a blast. Loooovin' it. I"ve never had a 9 foot screen before.

Speaking of screens, that's also on the list. I have an old Da-Lite screen on a stand. It has a patch on it where the reflective material flaked off. It's about 50 years old, and it's only about 4x4 feet. But I brought it out to see the effect on brightness, and it was a big improvement. eBay has screen material big enough for my picture for about $45. No idea how I'm going to mount it, though. Maybe a 1x2 at the top edge, screwed to the wall nice and level. Maybe another bound to the bottom of the screen material for weight to pull it flat.

HA HA yeah exactly! After I posted that I thought well he probably doesn't have audio to the panel. Then I had a Hmmm moment I bet he grabbed the closest cables and ran with it (I do this all the time) Love the desktop

Nice work guy!!! image looks very good and I dig your panel frame.
There are more than a few people in the forum who have made their own screens...

As for a brighter projector, if you're ambitious enough, you could replace the halogen bulb with a MH bulb...
It's not a 3M, but you get the idea. Not too challenging.
OHP MH Retrofit

First things first, I'm de-ghettoing a few things. I removed the upper part of the frame that holes the screen, and am getting it back together on just one piece. This way, it will be .5" from the bed rather than 1" and I'll get better focus around the edges (tests with transparency film confirm this). I'm also mounting the LCD controller clean on the frame, and dremelling off a piece of the aluminum screen framing so that my ribbon cable doesn't rest uncomfortably on it. I'll have updated pics tonight or tomorrow.

I've been reading up on DIY screens, and it's a little intimidating. I found basic instructions and I'm reasonably sure I could construct the wooden frame. I also found what appears to be good screen material, enough to fill my wall for $99 brand new from a storefront. 1.6 gain, grey pvc.

The part that intimidates me is wrapping the material around the frame. I'm not confident I can do it straight, especially if I staple it to the frame. They sell clip/bungee dealies that wouldn't require staples, but those appear to complicate the frame quite a bit, requiring a smaller interior frame around the back for holding the clips.

I found these on eBay for $200, not too much more expensive when you figure parts and tools and time to build the frame. But then I lose like 20" of picture from where I'm at now. I would gain quite a bit of brightness, though.

Ideas? Advice?

Actually, building the frame and stapling the material is easier than it sounds... once you get one side done, you simply move to the opposite side, and so on.

I understand that intellectually, but in practice I'm just not good at things like that. Mine would have wrinkles.
I think I'm just skipping the DIY part on the screen. $200 ain't so bad for an 80" motorized!

LOL
Um, no it's not!!!! mount the switch on the wall and you're golden!

One trick you could try for the slightly blurred corners is reverse your triplet... it's very easy and helped me immensely...

As for Left 4 Dead.... L4D2 comes out on the 20th!!!!!
I'll have the frying pan with a chainsaw side please.... to go!!!!!!!

Reverse my triplet? This is relevant to my interests. Details pls? I have a much more consistent image now with the panel closer to the bed, but she's still a little soft.

And HECK YES. I already pre-ordered L4D2. Checked out the early demo, and now I can't wait. Johannas, my new projectorpal, find me on Steam. Let's kill some zombies sometime The frying pan is hilarious, it's my favorite of the melee weapons so far.

Still haven't pulled the trigger on the screen yet. I've been trying to arrange things such to get the picture down to 80" to fit that cheaper pre-made screen, and not having much luck I may need to buy the materials anyway, since that's the most cost-effective way to get the size I need without having to sit a foot away from the screen

will do my friend! johannas1969 on steam!... I must preorder that as well...
I just painted my entire wall, first with silver, then bright white... it works awesome!

Reversing the triplet totally works. I had sharp image from corner to corner.

Then I took apart the triplet because I was curious, and got goosegrease or whatever all over the lens :/ It's fuzzy in patches now. I gotta take it apart again and get it clean.

I need to get some new pics taken, I've got the whole rig in a box now, cardboard so I can see where the holes are supposed to go and whatnot. Will replace it when I have time to build a proper one. The LCD controller is also cleanly mounted to the screen mount frame rather than sitting loosely nearby. We're gettin there! Just gotta fix a couple glitches and get a screen and I'll be ready to bring people over for movie night

Cardboard and duct tape are great for making mock-ups. I made an entire 15" projector using cardboard and duct tape. (No LCD though,and the lamp was a regular 150W incandescent. The image was a piece of acryllic with a test pattern drawn on it in felt pen.)

Once you've got a good working design, you can transfer it to something nicer, and more permanent.

hey Guy... how's it coming?
I read the other "post" about obtaining a triplet lens....
And due to forum rules, I cannot directly give you the site name, as it is a competitor of this one... but just google it.

site: google.com triplet lens

I hear you about the lack of parts here on the site... it is indeed frustrating, but seeing as the DIY movement has slowed in the past few years, due to the economy, and, most undoubtedly due to technology prices coming down, it's not surprising that lumenlab isn't bothering to stock anythign that wont produce a profit for them... but the forums are the bread and butter... I mean, seriously, you can get the parts anywhere... need a ballast? google it.. I've found CoralVue which is used frequently here for around a 120 dollars shipped... need fresnels... 3D Lens has any size and FL you'd need, including HD lenses now! (WIN!) Need a triplet? paste the above search code into your browser... or better yet... search the trading post... they currently have triplets there and fresnels too.

looking forward to pics of your cardboard masterpiece!
just installed L4D2 demo and will look you up