Hey guys,
I begin building the PJ this weekend. I am VERY excited.
Anyway, i figured i'd give you a little intro to my project.

First of all, I am not using the Lumenlab design, and did not purchase the plans offered here. I did however buy all of my optics here, so i figured that'd be good enough to have a thread here at lumenlab.com.

I am building my own personal design, but i would not have had a clue what to do without the help of people here and at diyaudio.com.

Components:
Liquidvideo A150x1 15" LCD monitor. Very nice. Thanks for the reference.
Sylvannia 400 watt MH lamp )the big honker), and ballast
Split fresnels from here
Triplet from here
3 fans from some place i forgot. Very quiet Panaflo fans

The lamp will have it's own chamber. It will be sealed off from the rest of the enclosure, and have it's own fan. Heat absorbing glass will be between the bulb and fresnels...The lamp assembly will have a curved piece of stainless stell behind it to act as a reflector. I will construct a pyramid between the lamp and fresnels... The isolated lamp compartment will cut down on overall box size, and will make the light brighter while keeping the rest of the enclosure cool.

I will seperate the first fresnel 1.5 inches from the LCD. The next fresnel will be angles 15 degrees for keystone correction. I am floormounting my PJ, so this is a must. After the second fresnel, i will onstruct another light pyramid from the fresnel to the objective lens. Again, this cuts down on sive, and keep unwanted light to a minimun.
Between the lamo and LCD i will paint everthing silver. From LCD to obj. lens, everthing will be painted black. The sliver is to reflect every bit of possible light through the LCD, and black is to absorb any unwanted lights from going throgh the obj lens.

I will use two fans to cool the LCD, fresnels, ballast, and other things. The intake will be betweet the first fresnel and LCD on top of the box. The fans will draw air past the LCD into the enclosure, then out the top of the box.

I am using a VD-Z3 (vdigi.com) progressive scan component video to vga converter from my dvd player connected to my k-world external xga tv box. Will be able to use progressive scan component video, s-video, composite video, and coax cable all conected to the PJ.

If all goes well i plan to be done in the next couple of weeks. I will post picutres througout the process. Be sure and check back.

Take care.

why liquid video monitor? is there something I missed when looking at them at my circuit city?

Is silver paint better than white? What if a person used actual mirror inserts?

If you were to go to all that trouble you would want to make a light funnel from the lamp to the panel. Just lining the box with mirrors wouldn't keep the light 'on axis'.

Where did you buy your "Hot Mirror"?

I am only painting the inside of the frame that holds the LCD and Fresnels. Not the pyramid because it is stainless stell and is already reflective. I don't recommend mirrors lining your box. It would be overkill, and not do mutch. The silver or white paint doesn't really do a whole lot, but is better than the color of wood. I am doing whatever i can to get as good of light as possible. I think silver is better than white as it is generally more reflective. Some people have used silver mylar (very mirrorlike) with great results.

The Liquid Video monitor was on sale and is identical to the CMV 1512 from Chi Mei. It is a very nice monitor that is easy to strip. Many people on this forum and diyauduio use it with amazing results.

Here are a few 3d autocad models to explain the design better.

Oh yeah, As for the heat glass, i am really only using a peice of thick clear glass. It will not absorb all of the heat, but it will help to decrease the heat to the LCD. The LCD should be plenty cool.

more

one more

ok, one more

Hi!

I'm very very VERY new to this, but after looking over your plans think this would be a lot of fun to try to get together! I liked your 3D modelling of the box you are planning (AC3D at a guess...), and as I was looking at it thought about a small design improvement/idea...

Would it be possible to 'hinge-mount' the second fresnel lense with weights and oil filled slow-response/hydraulic hinges? The reason I ask is that this way the fresnel would pretty much be an automatic keystoning thing then, regardless of roof/table/floor mounting. If there were a hinge/hydraulic latency of 3 seconds to finally adjust, it would give the appearance of 'magic' adjustment. Naturally, you would not want the swing to be too huge (you would lose part of the image at around 20 degrees in either direction, so a sweep of 40 degrees should be sufficient I'd guess...)

Has that been tried yet, or would it not work?? Just a thought, anyway...

actually, i am in the process of changing the design. I am making the second fresnel hinge in the center. I will not use the hyrdo type like you describe, but it will be a hinge nonetheless, and i think it should be effective. I have a whole new design based on threaded rods. The projector will have a coffee table built around it, but it could be taken out and mounted on a ceiling or anywahere. I am gonna take my time though, so i am sorry if it takes me a while.
Thanks for the comments.
Take care.

What is a light funnel?

Thanks

It is a pyramid shaped box lined with reflective material that goes from the lamp to the condenser fresnel.

Brain,

Do you think image contrast would be improved by masking the lamp so that only light coming directly from the arc reaches the Fresnels? I'm thinking a metal plate in front of the lamp that has a hole just large enough so that the full diagonal of the fresnels is illuminiated.

That would actually reduce your output. Some of the off axis light bounces around the enclosure until it becomes on axis and makes it through the condenser fresnel.

Ok, I can see how this would be the case but unless off axis light is totally reflected wouldn't it degrade the overall image contrast? I'm thinking that the mask (given that it has a shiny back side) would result in more on axis light reaching the condenser fresnel rather then less.

The only time you're really worried about interference is when the light leaves the condenser fresnel.

i'm very new in this kind of thing but i think thread is quiet interesting..hmmm

Glad to see you're interested. What part exactly? The PJ or the stuff about masking the light? Anyway, I have ditched this particular projector idea and started a new one. I should be finished with the new one in a couple weeks. I'll post pics as soon as i can.

Take care.