Home made projector!

[Chernobyl]

Hi Guys
I've been wanting to make a home made projector for some time after trying out a cheap TV projector on my PC a few years ago (amazing fun).
TomsHardware recently made an article on exactly what I wanted to do and provided confirmation that it works well.
http://www4.tomshardware.com/howto/20041113/index.html
This proof was enough to make my buying finger itchy so I got a 15" LCD from Ebay to start the project.
A BenQ FP567s V2 came, total cost including VAT and shipping was £135.

Specs:
Minimum of 400:1 and max 600:1 contrast ratio (depending where you read)
At best it has a 16ms refresh (worst figures are not stated anywhere). Its perfect for gaming, I've been using it for the last few days.
Resolution is 1024x768
Colours and brightness are top class

The next parts are the OHP and screen:

After researching I found that prices of OHPs in the UK are much higher than the US and shipping costs prohibit getting one shipped over as they are so heavy. Many models arent available in the UK too (ie 3M 1650 400W).
If buying a US model a power convert is required too.

I settled for a fantastic UK bargain, the 3M 1750. Ordered it from here:
(sorry, link removed, I just read the rules!)
Much cheaper than anywhere else I've found, £166 +vat (shipping free).
Its a 400W twin lamp (for failover), has low power mode for 50% longer life and puts out over 4000 Lumens! For improved clarity it has a Triplet lense.
I read in one place that it allows you to change the light colour tone . I will confirm this.
10 bulbs cost from £63 + post and last 180 hours each on full power. This is much cheaper to run than a 'real' projector.
The OHP isnt here yet, hopefully today

For a screen I will be using a big white sheet (my walls are dark wood sadly). This will be washed in a brightening agent and will suffice until I can afford something better. The projector should be powerful enough to produce a bright image.
To remove wrinkles from the sheet it can be carefully ironed or use a steamer. I'll try the steamer first to see how effective it is.
I intend to wrap the screen on a long pole. The screen will be suspended from the ceiling (in front of my telly) and drawn up and down on a pulley system.

I did read a long time ago that one way to improve the luminosity is to glue a certain type of white sand to to the viewing surface. I may try this, could be messy and the screen would have to be permanently mounted.

Some issues being looked at:
1) Prevent light escaping from the OHP into the room
2) Keeping the LCD cool (whilst not looking like a Blue Peter project )
This is essential and cannot fail! I may use 2 fans with independant power sources as overkill in case one fails. Its not expensive to do and could save the LCD screen.
3) Keeping the OHP as quiet and cool as possible. This may mean fittiing different fan(s) and modifying the OHP to give no restrictions to airflow. It may be quiet enough, I'll know soon.
4) How much is a nice round piece of wood 10 feet (ish) long?
5) cant think of 5 yet but I'm sure its coming.

Price so far:
£135 -1024x768 LCD
£195 -400W Projector

Still need:
Big sheet
Big piece of wood
Pulley bits
Luminous wash
Cooling things for LCD and maybe to quieten projector
Black material to prevent light escaping

I'm hoping this will give a 15ft diagonal picture, hehe.
If you have any ideas on making this project even better (on an unhealthy budget), please can you mention here. Thanks.

Pictures are coming after the OHP arrives.
I cant wait

Edit:
for first time readers, the projector has developed greatly and now uses a Metal Halide lamp with glass beaded 3 metre screen,
It is soon to be made into a High Definition projector, all details will be documented here.
My room is also a lot tidier

[robbie]

Please by all means PIX!!! We might even put your name up in lights!!!
Rob

[RussianMissile1]

how about making this a double project, and watercool the lcd!!!!!

[Chernobyl]

haha Missile1, u mind reader
the thought had occured, decided I'm not brave enough.
Air should be cool

But just in case...
The water cooling could be sandwiched between 2 layers of glass or plastic, placed between the OHP and LCD, stopping heat dead.
Not sure how much light it would remove though, it may change the visible light spectrum. You never know, one day I may find myself armed with a large amount of plastic and not much to do with it

Hi Robbie,
I can post some Pix of the monitor now but they are ultimately boring!
Havent had word from the OHP supplier yet saying they have taken money from my account. Hmm just called them, they cant find the order! Will know more later, they are to call me back. Doh!

[Gizmo]

Originally Posted by Chernobyl

I can post some Pix of the monitor now but they are ultimately boring!

Boring? BORING!?

Dude, you just BUILT a projector!! HOW can pics of your handiwork be boring?!

Ideally, of course, we'd like to have pics of the actual construction, or at least the innards....

[RussianMissile1]

maybe get two sheets of glass or plastic and use a dremel to engrave channels into at least one of the sheets, then sandwich the sheets together and run H2O through it.

i doubt algae could survive with such a high temperature being excerted on the sheets, so maybe you can use pure H2O.

^just a suggestion, if youre feeling brave^

[Daniel ~]

I'm amazed! Really!!!

[Chernobyl]

Excellent replies

RussianThunderbird1, I had a similar plan to yours for watercooling, I hadnt thought about Algae though. As you said, the water would need to be pumped around and also cooled. I hadnt considered algae, probably cos I've never had any in my watercooler. I have some washing up liquid in the water. Works like magic
The water channels would need to be outside of the viewing area which doesnt make them as effective, but I'm sure it would work quite well.

A funny thing I just thought about. When the suns shining, do the windows on your house ever get hot? the radiated heat passes straight through which means I'd still need a fan blowing on the LCD as it would slowly heat up.

I read on one report (probably TomsHardware) that the screen starts to go brown just before game over, dont want it anywhere near there! I imagine any increase in temp above its normal operating temp will not help its life either. Cooling the LCD reliably is one of the most important aspects. I dont have much cash to replace it either! (and I really like this one)

Maybe air cooling is best?

Gizmo, I have a photo of the monitor in use with an AOA page on if you like I wont take the LCD apart until the OHP arrives in case it has a silly fault. I want faults to surface before I rip it apart so I can get a replacement! All seems good so far.

I just got a call from the Projector people, Darn, It should be here early next week.

[Gizmo]

Throw up pics as you have them, Chernobyl. But keep us updated. I, for one, am really eager to see what you are doing and how you are doing it. This is SO COOL!

[Daniel ~]

For sure dude!! Takes us along with you while you work though this!

[RussianMissile1]

another idea for the WC:

get a sheet with an empty space in the middle, my pic shows the rest, cant explain. blue arrows show possible flow of water. maybe by doing it this way, it wont distort the picture at all.

that pic is exaggerated for clarity, the empty space should be alot thinner than that.

Originally Posted by Chernobyl

Maybe air cooling is best?

if not the WC, then do it with quad tornado fans..

[Gizmo]

I believe a lot of CRT-based projection TVs use an oil of some kind bathing the front of the tube to keep it cool. The reason is because the oil used has a diffraction characteristic that is extremely close to that of the glass used in the tube, so you don't have light scattering at the glass/oil interface, like you would with water.

[Chernobyl]

Wow, I didnt expect such enthusiasm, thanks everyone!
Hi Daniel, sure thing, I'll do my best to keep you in the frame.
I surrender Gizmo Heres the LCD screen I will be butchering (attached).

RussianMissile1, thanks for the diagram. I reckon I'm going for air, using 10 Tornadoes at .001V Just kidding, but I'd better draw a diagram of what I'm thinking..... (attached)
If you have more ideas throw em in.

Damn thats rough, it gets the idea across I hope..
Nothing is to scale btw.
The fan is intended to be silent. I want to have 2 fans, 1 each side of the LCD/OHP. One will suck, the other will blow. If one fan fails, the cooling should be nearly as effective.
Object(s) in the air tube will make the air a little turbulent before it reaches the LCD. This should help keep air moving at the edges rather than taking the easiest path across the centre of the LCD. Lots of trial and error to go on this.
I bought some ladies tights today I'm using them as air filters (honest!)

The whole dual fan assembly could be dropped onto the projector as one unit, providing the mounts for the LCD also
I'm hoping to make this from thin plastic sheet (another thing to find) and a glue gun.

A fan blowing down on the top of the LCD would be beneficial. This would provide good cooling over the back LCD surface and give a little peace of mind. As I will have a hood over the whole projector, this fan can be used to draw colder air into the cavity rather than circulating. (a diagram moment?).
Throughout the project I'll measure the temperatures across the LCD surface. I'm stuffed at the moment though cos I cant find my spare sensors. May have to steal the one from my CPU!

There needs to be either a fan failed warning or a high temperature warning. As this Projector will be silent (I can hope), so chances are I wont spot a failed fan.
Using this 3 fans method, it should have a pretty cool life

Gizmo, I was going to write about the same thing regarding oil cooled lights. It would be nice to get a cooled light in there as a real simple solution, I need to get some to see how they can be integrated, I've no idea of the cost yet. The projectors are setup to give a nice even spread of light, This may be hard to achieve with a different bulb/shape/size.

An oil filled cooling surface would be excellent. Do you know of any clear oils that catch radiated heat too?

[Gizmo]

Originally Posted by chernobyl

Do you know of any clear oils that catch radiated heat too?

I would think that pretty much any oil would catch radiated heat. As far as I know, all petroleums tend to be rather opaque to infrared light (heat). Unfortunately, you have pretty much exhausted my knowledge of such things.

[Chernobyl]

Woohooo
the OHP arrived!
Some quick piccies for you.
Now you can see how messy I live


I tried the low and high power settings and couldnt tell the difference!
I'll try again when I have fitted the LCD.
Its very quiet, I'm so pleased. There is a funny knob that if you fiddle with it, it goes even quieter. Fiddling more makes the picture go funny. Strange that, happens with other knobs too

It looks really nice, but it sure fills the room with light. At least now I know its dimensions I can start to build a cover for it.

More to come.......