Home made projector!

[Chernobyl]

haha, still waiting for that miracle

[Daniel ~]

"This to shall pass". ":O}

[Chernobyl]

I did some research on bulb colour temperature the number that classifies the output colour of the bulb.
Ideally daylight has a colour temp of 5600 Kelvin.
I just found my bulb (Halogen) has a colour of 3400K, bang in the middle of bright yellow!! That one good bulb must have been a rogue. Was a good experience though

Colour temp chart:
http://www.mediacollege.com/lighting...mperature.html
My bulb specs:
http://www.donsbulbs.com/cgi-bin/r/b.pl/o-64663.html

There is my problem with the slight yellow tint!
3400K is classed as warm (under 3500K), 5600K is halfway between Intermediate (3500K+) and Cold (6500K+). A colder temp bulb than 3400K would work better.

I get the feeling I'll be cutting the bottom out of my OHP some time soon to fit a new bulb type!

The best bulbs for LCDs are around 5500K. An ideal bulb is this:
http://www.lamptech.co.uk/Spec%20She...m%20HTI400.htm
but its life is only 250hrs and they cost maybe 10x the price of mine.

I'll do some more research as its not easy to make the best choice.
I'm looking for:
a Metal Halide or hybrid of
250 to 400W
at least 25,000 Lumens
10-20,000 hrs life
52-56000K
preferably a small device with a dichroic reflector but I may go for fat 400W and no reflector Something in between would work too but involves get a decent reflector for the type of bulb.

Back later

[Chernobyl]

I've found the right bulb type to use!

its a Metal Halide HQI-ST type (aka HQI TS) 250W or 400W.
The 250W are around 20,000 Lumens, the 400W about 35,000 Lumens !!!
(The original 400W projector bulb is 13,000 Lumens)

Its is a compact double ended Metal Halide bulb that will mount fine at the focal point of the current bulb without cutting the case open.
The colour temp varies, I have found some in the 5000K to 6000K range though.
Some have built in UV filters too like one made by Osram, but boy are these hard to track down. I dont even have a part number for it yet!

Using different Ballasts (electrics) and/or Dichroic reflectors, the colour can be varied quite a bit. Some Dichroic reflectors shift the bulbs colour temp all by themselves!

The bulbs are usually operating somewhere near 50% of their max brightness by the time they die and some do colourshift a bit too. There are bulbs around that are resistant to colour shift, not sure if they make them in this type though.
I think a 400W bulb might be best to keep the brightness up.

The heat produced is much less, as more energy is converted into light, so a cheaper triplet lense 250W OHP may be able to take one of the 400W bulbs!

I'll be making some phone calls tomorrow to see where they can be found in the UK.

Oh yes, they are damned cheap.
10,000 hours plus, 250W around £20, 400W around £40.
Yahooo!

not sure of the electrics price, but a combined bulb with electrics can be found for about £60-£70.

[Chernobyl]

A quick note before I write about my latest discoveries.
Using the information in this thread and other things found, I will eventually create a full decription how to make your own projector system cheaply and as easily as possible. Some of the details involved in getting there are technical and required to make the best decisions during my investigation. Its easy to accidentally choose parts which will not make you happy with the end product.
I will cover the essentials after the project is finished to make it easy for you to decide if what you are buying is suitable. I will also cover how to fit any new parts and the issues involved. This will no doubt restrict the types of some components, I will try and give a gauge how badly a 'wrong' component will affect the projector too should you come across some parts cheap or free.
Dont let the detail being exposed here put you off trying to make your own projector!

The results I have with a very wrong bulb (3400K) are extremely impressive.
The bulb I have has a weak blue output. Blue has a mild yellow tint to it and white is mild yellow. Reds, yellows and oranges look stunning! Changing the bulb to a full light spectrum centering around approx 5200K white light will bring all the colours into balance including white. These bulbs are very cheap, way cheaper to run than the current bulb I am using which is approx half the running cost of a purchased projector.
In my view, changing the bulb will nearly perfect making a top notch projector at 1024x768 res!

The only problem left is the loss of about 1/15 to 1/30 of the pictures side. Its a minor issue and I can certainly live with it.
Screen definition, resolution, speed and size are superb.
The screen is 5ft diagonal now which to be honest is perfect for watching TV.
I hope to make it scale to 80"+ for films and gaming with a new very bright Metal Halide bulb.

It should be easy to allow the screen size to be varied.
With a powerful bulb, it may be too bright with a smaller display. Metal Halide bulbs cannot adjust their brightness (not for the price we are paying!) but a filter to dim the light output of the projector can be used instead.

At any time if you consider anything I have said needs correcting, please feel free to discuss it here. There have been a few times during the project where I have wandered down the wrong path and tried to draw conclusions without a full barrel of knowledge. Theres certainly a lot to cover and more to go.

Onto the game!
As well as the Colour Temperature of a bulb, there is another indicator of colour on many bulb sales sites called CRI (Colour Rendering Index). This has been found to be vital when considering the best bulb for the projector.
Here is a pretty good description of CRI and the Colour Temperature:
http://www.lightsearch.com/resources...ormetrics.html

The CRI takes 8 points on the light colour spectrum and uses the colour of lit objects at those colours to give you a CRI value of the bulb. The higher the CRI, the more natural objects will look when they are lit by that light.

A CRI of 100 is perfect.
A CRI of 80 is considered very good. Values below that can affect your colours in unknown ways, but values below 80 may still be acceptable. I will find out.
High CRI values on a wrong Colour Temperature bulb will not make it work well on your projector.
Once you know the colour temperature (5000K to 5600K), the bulb is then chosen which is/has the right type, size, fitting, shape, power, CRI, cost and availability. There may be more to add to the list, thats my knowledge so far

Choosing a bulb with a high CRI is very hard when browsing online as most websites dont display the CRI value. Many dont tell you the colour temp either. I will find out soon how helpful shops are at finding the right bulb.
More to come.

[Chernobyl]

This may be the perfect bulb!
HQI TS 250W UVS and a 400W version.

Spec for the 250W:
uv block
5500k
90 cri
20,000 lumens

I cannot find a spec for the 400W , It 'should' be the same with 30,000+ Lumens
Best of all is the price.
250W £26.09 inc
400W £39.48 inc

Now I need to find a balast for it.
There are 2 types of balast, noisy and quiet
The quiet one costs more, I need to find out how noisy the cheaper ones are.
I dont know prices of either yet.

[Chernobyl]

I received an email from a supplier of bulbs in Germany after asking for info through his web page.
He said that these bulbs should drop straight into an OHP without issue. Bonus!
His email address bounced when replying, so I'm not sure I'll buy from him.

I called a supplier in the UK and the guy on the phone was very interested and helpful.
This is the supplier of the bulbs I mentioned earlier.
Sadly the 400W is mislabelled and not UV stopping but he may have others worth looking at.
He is getting back to me on the cost of a Ballast, I will make more enquiries.
I have given him the address of this thread, so if you are reading, thanks Steven

I may end up getting the 250W version as it is quite tough to source anything fitting the bill, 400W kit being hardest of all. I'll see what Steven can come up with.

[Daniel ~]

We're all hoping you come through Steven! ":O}

[luke_t]

Hi,

Firstly congrats on building some good projectors, I have been trying this myself on and off for 2 month now. I've had some success but I've been very unlucky in my tft screen purchases.

Firstly I had an old IBM TFT screen that was 14.1" which was perfect for my 3M projector (400W halogen, very similar to cesiums). However upon taking it apart I discovered that there were 2 strips of printed circuit board along the horizontal and vertical of one side which were conected by a very short ribbon. This meant that when the pcb's were folded back out of the way of the screen the ribbon was no longer long enough to connect them. - result - Fail

Second attempt was a Samsung 152v which I decided to buy from a well known pc retail store in the UK. I got this screen because I saw on the tomshardware site that similar models (152n etc.) were recommended as suitable screen for this project. Sure enough it was great, until disaster struck and one of the pcb stubs on the right of the screen riped off (see photo) this effectivly took out the bottom 1/3 of the screen. - result - fail

Third attempt was a replacement Samsung from that well known pc retailer, however upon opening this screen I noticed that the inards were different from the first one, and I now had a monitor with a small ribbon cable that would not allow the pcb's to be folded back. Just like my first attempt... luckily I managed to take this back and get a full refund. - result - fail.


So now I'm still after a suitable TFT monitor for this project, I haven't lost any money yet so I feel quite lucky. At the same time I'm fraustraed as hell because I have a projector, projector-screen and cooling method... just no damn tft screen...

Any recommendations would be greatly appreciated.

Thanks, sorry for boring you all with my attempts!

Luke

http://www.carshockcontracts.com/images/tmp/Photo.jpg

[Chernobyl]

Originally Posted by luke_t

Hi,

Firstly congrats on building some good projectors, I have been trying this myself on and off for 2 month now. I've had some success but I've been very unlucky in my tft screen purchases.

Firstly I had an old IBM TFT screen that was 14.1" which was perfect for my 3M projector (400W halogen, very similar to cesiums). However upon taking it apart I discovered that there were 2 strips of printed circuit board along the horizontal and vertical of one side which were conected by a very short ribbon. This meant that when the pcb's were folded back out of the way of the screen the ribbon was no longer long enough to connect them. - result - Fail

Second attempt was a Samsung 152v which I decided to buy from a well known pc retail store in the UK. I got this screen because I saw on the tomshardware site that similar models (152n etc.) were recommended as suitable screen for this project. Sure enough it was great, until disaster struck and one of the pcb stubs on the right of the screen riped off (see photo) this effectivly took out the bottom 1/3 of the screen. - result - fail

Third attempt was a replacement Samsung from that well known pc retailer, however upon opening this screen I noticed that the inards were different from the first one, and I now had a monitor with a small ribbon cable that would not allow the pcb's to be folded back. Just like my first attempt... luckily I managed to take this back and get a full refund. - result - fail.


So now I'm still after a suitable TFT monitor for this project, I haven't lost any money yet so I feel quite lucky. At the same time I'm fraustraed as hell because I have a projector, projector-screen and cooling method... just no damn tft screen...

Any recommendations would be greatly appreciated.

Thanks, sorry for boring you all with my attempts!

Luke

http://www.carshockcontracts.com/images/tmp/Photo.jpg

Hi Luke
thanks very much for your input, this is exactly the sort of thing I would like to know.
The 2 screens I used were from BenQ and Iiyama. The BenQ has a yellower tint than the Iiyama and was prone to failure too. The Iiyama is a little diamond. I got the E380S model and recommend it if that helps

[luke_t]

Hi,

I got another Samsung 152v today, and unortunatly this sufferers from the same design problem as my last one. I must have either had an older model in the first one I purchased. Needless to say I packaged it back up and shall return it in working order tomorrow.

Cheers for the recomendation, before I go out an buy one of these could you tell me...

1) Is the unit straight forward to dismantle without cracking the plastic shell... The samsung was very good for this, i've now packaged 3 of these monitors back up.

2) I noticed on your pictures that you have mounted the pcb's vertically, did you have to do this due to the cable length / ribon length?

3) Can you suggest a cheap place to get one from?

Cheers
Luke

[Daniel ~]

Hello Luke and welcome to AOA...

I've taken the liberty of extending your request for help to our front page...":O}

http://www.aoaforums.com/forum/showt...907#post291907

[luke_t]

Hi,

I got another Samsung 152v today, and unortunatly this sufferers from the same design problem as my last one. I must have either had an older model in the first one I purchased. Needless to say I packaged it back up and shall return it in working order tomorrow.

Cheers for the recomendation, before I go out an buy one of these could you tell me...

1) Is the unit straight forward to dismantle without cracking the plastic shell... The samsung was very good for this, i've now packaged 3 of these monitors back up.

2) I noticed on your pictures that you have mounted the pcb's vertically, did you have to do this due to the cable length / ribon length?

3) Can you suggest a cheap place to get one from?

Cheers
Luke

[Chernobyl]

Hi Luke
The Iiyama was fairly straight forward to strip apart. Thats my opinion, others may vary Nothing needs breaking and it will go back together ok as long as your remember what goes where.

The reason I mounted vertically is to keep it as one solid unit. This means there is no flexing of fragile parts and you never need touch the electronics so can eliminate static problems from touching it. Its extremely easy to move it without causing any damage.

You rely on Lady Luck for the most part if you want to get these cheap. I got a year old LCD off Ebay for £112. it does have its problems in that the power button rarely works and I have to unplug/replug in the mains a few times to make it power up. It does always work though.
Buying from Iiyama direct it costs £180 ish, not sure what you'd pay if you are in the US.

[Cesium]

luke, looks like you have the 3m 9200? thats a good upgrade from the one i have, though id still like to get my hands on a 9550

yeah, my cmv 522a works perfect, and my brother got a 5000 lumen elmo ohp and is going to use his cmv529a, which appears to be the same exact model, only silver. The reason the cmv's are great is because they have a very good contrast ratio, 16ms response time, cheap price, are a breeze to take apart, and they of course place nicely on an overhead (as you can see from my previous picture on post #130). Im sure i could find some extensions for the ribbon cables too if i wanted

as im clear out of funding, no new ohp for me, but i'll probobly make some sort of apparatus to hold my lcd stuff in place. I was thinking about 2 glass panes to go on either side of the tft and connect them together, then i could make 4 holes in it, stick 4 nails in the ohp and jsut place the panel down where i want it and it will stay put. still need to do something about the pc boards though

[Chernobyl]

Originally Posted by Cesium

luke, looks like you have the 3m 9200? thats a good upgrade from the one i have, though id still like to get my hands on a 9550

yeah, my cmv 522a works perfect, and my brother got a 5000 lumen elmo ohp and is going to use his cmv529a, which appears to be the same exact model, only silver. The reason the cmv's are great is because they have a very good contrast ratio, 16ms response time, cheap price, are a breeze to take apart, and they of course place nicely on an overhead (as you can see from my previous picture on post #130). Im sure i could find some extensions for the ribbon cables too if i wanted

as im clear out of funding, no new ohp for me, but i'll probobly make some sort of apparatus to hold my lcd stuff in place. I was thinking about 2 glass panes to go on either side of the tft and connect them together, then i could make 4 holes in it, stick 4 nails in the ohp and jsut place the panel down where i want it and it will stay put. still need to do something about the pc boards though

Hi Cesium
glad you're still with us.
Your screen sounds very good too, thanks for posting it.

Are you interested in putting a more powerful and correct colour lamp into your OHP?
I'm getting close to buying one for mine that is not only brighter, but cheaper to run, the correct colour for LCDs and lasts a LOT longer too (in the region of 5 to 10,000 hrs)!
250W and 400W versions can be used, the 250W being much cheaper (overall) and still brighter than my 400W Halogen bulb.

They dont seem at all expensive, I hope to get the whole kit together for £80 to £100. Cant wait, especially as I have no bulbs at the moment. They should arrive tomorrow

I'm very interested to see if 250W OHPs will be as good as 400W ones as the price difference between the 2 could mean the lamp upgrade pays for itself!
I cant see any good reason why it wouldnt work very well with a good spec 250W OHP.

[Chernobyl]

In the interests of finding which LCDs are good for the Projector, this thread has been created to list the LCDs and where to buy them hopefully cheap!
http://www.aoaforums.com/forum/showt...208#post292208

If you know of anyone who has made a home made projector, can you find out if they are happy with the screen. If so, please tell us.

Cesium can you let us know where you got yours from or of any bargain places you know for it?
thanks

[luke_t]

Thanks for the replys guys,

I've included some photos of my projector setup, my projector is the 3M 9550. Sounds like its a good one to have... could you tell me why?

On the photos you can see my diy cooling method, its basically an extractor fan that is powered off the mains supply to the projector. The box channels the air through to a 1 cm gap the width of the ohp glass.

I saw on cesiums images that he cut out the corners on his ohp, I think I relly need to do this too. Also did you remove the glass from the top of you ohp, because I find it to be a heat shield... operating temperature of a screen on the projector was 34 degrees. I'd imagine that without the glass panel there it would be maybe 5+ degrees higher?

I'm going to carry on searching for a screen today, the trick is to find one you can take apart easily, without destroying the case.

Cheers
Luke

http://www.carshockcontracts.com/images/tmp/ohp1.jpg
Picture1

http://www.carshockcontracts.com/images/tmp/ohp2.jpg
Picture2

[Daniel ~]

You guys amaze me! ":O}

[luke_t]

Btw... thanks for putting my efforts on the front page, it was a nice touch!


Cheers
Luke