Hello, I decided that I would build a DIY projector about three years ago, over that time span I have managed to acquire the following parts: 1000W Metal Halide Light Source, Tyris 17" LCD Display Unit, SXGA Scan Converter, Four-Element Varifocal Lens, and a 17" Fresnel Lens. I halted construction due to separation of my resources (family divorce) but I will be moving back into my home in about one month, so I can continue construction. I have the following questions: Is it alright to build my projector with a steel or aluminum casing (painted black internally of course), is the Tyris LCD panel actually strippable, and (how long) can my LCD withstand the intense amount of energy it (UV radiation etc..) will receive from the light source. I will be cooling this unit with two industrial grade 90mm fans, which I believe should be more than sufficient. Thank you for your time.

Best Regards,
SkullStatue

Two 90mm fans, no matter how industrial, will probably not be sufficient. Very few people have even tried to use 1000w lamps because of how much heat they produce. If you do proceed with that plan, I wouldn't even put the LCD in the enclosure with that lamp until you measure how hot it gets in there.

Just my $.02.

Thanks, yeah, I will need to check the heat. But these are some of the best fans I have ever owned, they can move plenty of air. If I put my fingers in these fans then I will most likely lose them, I'm not sure if they are 90mm or 120mm but they won't fit in a standard ATX case or anything. If they don't work I can get some bigger ones, I really need to know if the Tyris brand monitors are strippable because I can't afford anything else. I have searched far and wide but no one knows, I am pretty sure someone here must know since this is one of the largest DIY websites on the internet. I have heard of a couple of people using 1000W light sources with very good success but I do know heat will be one of my primary issues. I can always add a couple of fans in case things go bad.

Sorry for the double posting but I need to know if the varifocal lens (bought it from DIY Projector Company a couple of years ago) will be compatible with a 17" LCD, the description stated it was specifically designed for 15" LCD's, but it wasn't confirmed to work with anything bigger. Has anyone used anything larger? Also, what is the variable focal length of this lens? Is it any different from the one LumenLabs is selling? It has a purple coating and protective covering, the one here looks clearer and alittle bit different. Sorry again, I just need to know before I start welding...

Don't want to be the bearer of bad news again, but I would have to guess probably not. A 17" LCD stretches the standard lens to its limits and every varifocal I've seen (except LL's original pro lens) has a field of view that is smaller than the standard s15 lens.

I couldn't find any exact specs on the DIYProjectorco varifocal but this page suggests it focal length is approximately 220mm (now whether that's the bottom, top, or middle of its range, I don't know).

That's smaller than the LL varifocal, which typically suggests a smaller FOV as well. Joechevy, who has used the LL varifocal on at least one projector and seems to be one of the more knowledgeable members re: its limits, says in this post that 15" is the largest LCD you can use with it.

FWIW...

OK, I tracked down the FL of the DIYProjector Co. varifocal: 217 - 229mm
(found here--look under the lenses section. Note: this link is a Google cache and will self-destruct in ??? days)

Thank you for tracking that down for me I really appreciate it. My original design was a 15" so this isn't too bad of news, I have a 15" monitor and another 15" fresnel lens but it's very difficult to find a power supply for the LCD and since it's so old it's probably not worth the effort. I will need to order a new one, I might try some of BenQ's or LG's stuff. Thank you again, I am so happy you helped me, if it wasn't for you I'd have a giant welded mess sitting in my garage right now. Thank you again!