DIY Video Projector

[Myren]

38 photographs detailing the disassembly of my recently recieved lcd. i'm going to strive to post before i'm kicked out of dorms for spring break, and i'm going to try my best to make sure they dont routinely unplug my server in my absence.

i swear to god though, if i hear one person bitching about lack of instructions or lack of photos, i will hunt them down and make them pay.

the crappy digitals i loan from people seem totally unable to take anything resembling a decent picture. i refuse to post the **** i'm getting now. anyone have suggestions for how to get these light mongering bastards working in decent order in a relatively low light environment? if not, i'm going to have to use my 35 mm, which means it'll be a month before they get posted.

myren

[Myren]

if you use your head, you should get quality roughtly equivalent to a projector thats costs x 10. $100 => $1000 of quality. $300 => $3000 of quality.

[frankbatzen]

Well, as you know, I am using the ohp-route. All I used from a really old an crappy ohp was the housing and the optics. On monday or so I watched tv on a diagonal of over 3,5 meters with an inverted picture. The picture was much too big to watch comfortably, with the loudspeakers standing in the way and so on. From ebay I bought an f=400mm projection-lens (actually it's several lenses combined in a metal tube, what is that called in english? objective?) With this lens, the picture size is perfekt with the ohp hanging from the ceiling at the opposite side of the room (2,6m diagonal picture size). Most of you probably know that for any given distance of an ohp to the projection surface or for any given lens-setup the distance of the lamp to the fresnel has to be adjusted. Without doing that you can only focus the very center of the projected image, everything around it is very blurred. I had adjusted my lamp for the f=317mm lens, so with the new f=400 lens I have to readjust the lamp-fresnel distance. This is what I will be doing today. This is pretty shitty, since I desinged the projector in a way that doesn't foresee repeated reopening. Doing so is very bad for the flexible ribbon cable connecting the PCB to the display, which has to be disconnected for opening. It only allows for 30 cycles. 2 and counting. I probably will have a digital camera for the weekend. I need to find a way to post them. One concern I had with the new optics was the (focal width? what do you call f=?) of the fresnel. The fresnel focuses the light of the lamp directly into the projection lens, always at the same distance from the fresnel. Obviously there has to be some tolerance, since you change that distance for focusing, but I was not sure if 400mm would be ok. It is. That's good.

Some more things that are important IMHO:

1. There very likely will never be a list of parts to use. Many people buy from ebay, so you have to be lucky to get good parts and FLEXIBLE to go with whatever you get for cheap.

2. Use this forum for inspiration, not instruction! I was inspired, or let's say encouraged to use a tft-flatscreen monitor as my projector's display. However I found out by myself how to use it, which wasn't easy. I am sorry to say this, but I think everybody who relies on exact instructions to build a projector will probably fail, since you will always encounter problems to be solved by yourself.

3. Using old notebook-tfts to connect to standard vga is the holy grale of diyers, which implies that it is not real. I tried to find information on that for a couple of months a while back. Please note: IT IS NOT POSSIBLE AT A PRICE BELOW A STANDART DESKTOP TFT-MONITOR. Thank you. I have a 800*600 notebook-display laying around. Still wanna buy?

4. Use Hqi-lamps from industrie-floodlights or sweetwater (not seawater) aquarium-lighting. I just vomited into my keyboard when I read you were THINKING about buying bulbs at 320$. Mine is as bright as these and costs 25$ new on ebay.


Ranted enough.
g!zmo

[jamie]

your right when there finished they dont come back with the progress report so here is mine i tryed the tracer drawing projector and a 5 inch crt tv portable not bad, simple but not good enough so i took back the projector to the arts and craft store cause it was so simple to build a mirror light buld and lens

so in going to build my own and try an lcd so i can use the light
as im sure a lot of you no if you shine light on a tv the picture just goes away when i get mine working i will report back with instructions please eveyone do the same!


jamie

[jjasniew]

Myren,

To use a LCD camera in low light conditions, a tripod stand is a
must, because the shutter opening is so long.

Gizmo,

When you suggest some part that will save someone a lot of money, could you please post the precise part number?

Markprojector,

When you say you got an 800X600 panel and it works great, could you also post the make and model number?

-------

You guys notice when I post statements about my stuff, I say ELMO HP-A350, Nview Z350, Infocus panelbook 500e, Dukane 4003, Viewsonic VB50, etc.

This lets people know exactly what to look for, to replicate the performance I'm getting. I dont just say "Got an OHP with a metal halide and a 1024X768 with a line doubler - looks great, here's a picture!" That doesnt tell anyone much of anything. Then you have to ask, and hope whoever made such a statement gets around to posting again.

If you have reason to hide what the equipment is, such as "I'm going to sell these systems and I dont want everyone knowing how I did it" then just say so -

[Bitch]

Here's my instructions:
1) Get powerful bulb (choices are endless).
2) Get projection lens, anything that is cabable to do the projection.
3) Get LCD, anything that accepts VGA or video.
4) Get fresnel lens to condense the light if need to.
5) Get few fans
6) Make a box
7) Drill holes to the box for the lens and fans.
8) Place the bulb to the end of the box.
9) Attach the fresnel to the LCD.
10) Place the LCD in.
11) Place the projection lens in.
12) Focus the thing by moving the LCD and the bulb or devise some sort of focusing system and you're ready to go.

The problem is that we are all taking different routes. Various components and setups. And when somebody might be happy with something, for someone else it might not be good enough. Saying which setup for all of the ones people have made here cannot be compared unless we setup some weird **** f*ck diy-meating at some hotel in Russia where everybody brings their projectors with them and then we start comparing. Pics don't tell what it really is. And there are differences in opinions. And stuff. I don't know if I'm making any sense but the BASIC INSTRUCTIONS for building the thing has been presented at this forum several times (even I pulled it off, just couldn't get the cooling to work), there are loads of different setups and stuff here. Just take your pick or improvise.

[fender4]

I agree with jjasniew...it would help tremendously to post the model #'s for the equipment that we use, even if it doesn't work well. At least it could help us generate a list of what is useful and what is not for this project. For example, I know that the Sharp LQ6NC01 5.6" LCD will not work because the driver board is not movable. It is sometimes available on Ebay.

After asking around, I have heard that many of the OHP panels suffer from blurring or redraw problems. Contrapasta posted earlier about motion ghosting with the 640x480 panels at Inventory Soultions. I think the model he is referring to is the "NView Spectra C". Has anyone else experienced motion ghosting?

I think I will order the 800x600 (don't know the model) despite low motion performance expectations. I will post full details once I put it all together.

-f4

[oftheend]

For anyone working with CRT's, here is some good info about avoiding the near-death voltages. The first two are general saftey, including discharge instructions, and the third is the screwdriver discharge method. There is also info about other houshold risks.



http://www.qsl.net/k3pgp/Notebook/La...ety.htm#safgui
http://www.concentric.net/~Redward/Safehlp.htm
http://www.playvectrex.com/shoptalk/...ischarge_f.htm

[Grumpy_Git]

look, I know absolutely none of you are interested but i want to ask a question.

To anyone in england, does anyone know of a half decent a/v surplus store in the uk where I could get an lcd ohp panel cos i've had enough of being outbid on ebay for lcd panels, they just get too damn expensive.
The US surplus place linked earlier wants 90 dollars to cover delivery, once i've paied for the panel, for that money I could buy a 15"TFT.


frankbatzen: Ceiling mounted? thats a big box you must have bolted to the ceiling, still it shows things are getting a bit more home cinema and less diy-shed

[ISI]

Hi,

This is Bob from inventory Solutions. We have recently learned of your project and have been receiving many phone calls, thanks to all!

I just wanted to let you know that we have years of experience in video projection. In addition to teh LCD panels and OHP's we also have screen material, CRT's, cables and many other peices of AV gear that might work towards your final goal.

Pelase write or give us a call, Bob 1# or Greg 2# (404) 355-6147.

We are in Atlanta, EST.

Regards,