Building your own projection tv

Quote:

---

Originally Posted by tracydani

I did not know you couldn't use a condensor with the 400 watt bulb. What about if you have the glass between the fresnel and the bulb? I believe I saw one that has 1/4 - 1/2" glass that helped with the heat. Is the condensor more fragile then the fresnel?
...

The keystoning...... Isn't that usually handled by gravity? Have them hanging from the top and free on the bottom? It seems that is what I read most.

So many aspects to decide on. This is a lot of work and I haven't even started :lol:

---

I haven't seen a design where the tempered glass goes before the condenser. I'll have to look into that.

When you mount the projector on the ceiling or floor and the image projected will no longer be perpendicular to the screen or wall and the top or bottom of the image will be narrower. Keystoning is when you tilt the collector fresnel to compensate for the angle. Otherwise the projector must remain perpendicular to the wall or screen. Tilting the 2nd fresnel is easy enough but making an external adjustment control mechanism seems like a lot of work (without suffering light leakage).

BTW, the IKEA napkin holder looks pretty cool :) but I'm thinking about this because I want a bigger bowl:
http://www.edmundoptics.com/images/catalog/984.gif Large Parabolic Reflectors @ 12", 18", and 24" from Edmund Optics

Using the gravity method for keystoning seems to work. I think I have only seen a couple that have them set for external adjustments. Then of course slightly tilting the screen if further adjustment is needed.

How expensive are those reflectors? They look good :) Anything I do can't involve welding though because I have no tools. Gotta be pretty basic for me and the wood will be mostly cut when I buy it.

That's one of the things that worry me on some designs. Especialy when they are gutting the reflectors to get the bulb closer.

Parabolic Reflectors: 12"=$40, 18"=$50, 24"=$78

The ones I really want are the Cold Ellipsoidal Reflectors (CLICK HERE) but the bulb will be much too large for the reflectors.

Are those holes in the center? Can the light be mounted through the holes? Also, which bulb are you using? The LL bulb would be too big, but what about this one.

http://www.bulbconnection.com/ViewIt...28PS/item.html

It has a smaller profile that may just fit and good output as well.

Those cold reflectors look pretty good.

I was going to get the 400w complete Light Kit for $159 from LL. Now I have to take a good look at your link. :P

That bulb goes with this ballast and mogul.

http://www.hidirect.com
bulb - Part # 40124 Venture 400w ED28 = $35.48
mogul - E39 = $4.50
ballast - V90D612 = $66.85
Free shipping! total = $106.83

Not sure if you can buy from this company, but this is a recommended set-up. You may be able to get it from another source. Apparently those items are not listed at the site, but you can call for them :)

top tip: don't listen to dickheads who want to put it in a box. you just end up breaking the bulb, spend ages trying to get it to focus, have a really faint picture because you can't get the new light that wasn't designed for the job to work efficiantly and get overheating problems

well i tried to get pics using my sisters camera. it's stupid, the screen on the camera shows the wall OKish then when i click the button it forgets what it's doing and messes the picture up. i know there's a lot of fine tuning to do yet but it's alright :snooty:

http://img323.imageshack.us/img323/9136/dsci00047ma.jpg
http://img323.imageshack.us/img323/1125/dsci00063qb.jpg
http://img376.imageshack.us/img376/8736/dsci00084vc.jpg
http://img72.imageshack.us/img72/4784/dsci00110xh.jpg


edit: btw that is woodchip wall paper with a rushed paintjob :pinch:

those pix are ridiculously bad :|

i did say