So after a few months of hearing about/researching the whole DIY projector market, I started lurking here and lo and behold, ended up finally breaking down and buying a LL megakit (figuring that once I actually had parts I couldn't put off construction any longer). I also grabbed a Dell E151Fpb on ebay, so as far as I know, I'm all set for parts.
I'm at college right now, and luckily am surrounded by some keen engineering students in my house. Even better, my very handy/project-loving dad offered to build my PJ box if I could give him some plans/dimensions. Right about now is when my head starts to spin and I slowly lose faith...
So I would love to give my dad some plans, as I definitely need to get my box going first, however, I am at a complete loss as to where I need to go from where I am at. I've seen so many different plans and theories that I'm just lost in measurements etc. and don't know what at all I should be doing to get these plans drawn up. I am just looking to put together a standard 15" big rectangular box style, so I know I don't need to worry about anything fancy with that. Still, I just don't know where to start.
So, I am looking for any and all assistance I can get to help push me in the right direction and into the stages of actual production. Any advice as to what I can do to start determining/researching dimensions and plans would be somewhere in the vicinity of "priceless", so I will no doubt be forever grateful to anyone who can offer any assistance! Thanks for all the PLOGs and posts so far, I hope that with your help I can soon finally get back to having a TV in my room!
First off "my first 15[inch] disaster" is hilarious!
OK, dimensions...
An "unsplit" design is going to be the easiest to figure out, and it'll give you a better picture, but keystoning isn't easy.
You'll want some play or leway with all these, so be prepared to move them around...
Well, the distance from the bulb to the first fresnel (the collimating fresnel) is easy, just use the focal length of the fresnel (220mm). This distance has nothing to do with the projection, it is only the most efficient distance to gather light.
After that, you want to leave a little space between the collimating fresnel and the field fresnel, this space will help reduce "rainbows" and other arborations you want to avoid, it'll also let air move between the fresnels for cooling. After the rest of the dimensions can be estimated with the Focal Calc II. Keep in mind that (aparrently) the reported focal lengths of the fresnels are not exact, and you'll want to leave the door open for adjustments here.
You might also want to check out this post I made a while ago...
If this doesn't answer your questions, it would probably be good to post them into that thread...
OK, dimensions...
An "unsplit" design is going to be the easiest to figure out, and it'll give you a better picture, but keystoning isn't easy.
You'll want some play or leway with all these, so be prepared to move them around...
Well, the distance from the bulb to the first fresnel (the collimating fresnel) is easy, just use the focal length of the fresnel (220mm). This distance has nothing to do with the projection, it is only the most efficient distance to gather light.
After that, you want to leave a little space between the collimating fresnel and the field fresnel, this space will help reduce "rainbows" and other arborations you want to avoid, it'll also let air move between the fresnels for cooling. After the rest of the dimensions can be estimated with the Focal Calc II. Keep in mind that (aparrently) the reported focal lengths of the fresnels are not exact, and you'll want to leave the door open for adjustments here.
You might also want to check out this post I made a while ago...
If this doesn't answer your questions, it would probably be good to post them into that thread...
Thanks!! I'll be applying this stuff/using the focal calc and will be back soon with more questions!
QUOTE (Hirudin @ Sep 5 2006, 03:43 AM) 
First off "my first 15[inch] disaster" is hilarious!
OK, dimensions...
An "unsplit" design is going to be the easiest to figure out, and it'll give you a better picture, but keystoning isn't easy.
You'll want some play or leway with all these, so be prepared to move them around...
Well, the distance from the bulb to the first fresnel (the collimating fresnel) is easy, just use the focal length of the fresnel (220mm). This distance has nothing to do with the projection, it is only the most efficient distance to gather light.
After that, you want to leave a little space between the collimating fresnel and the field fresnel, this space will help reduce "rainbows" and other arborations you want to avoid, it'll also let air move between the fresnels for cooling. After the rest of the dimensions can be estimated with the Focal Calc II. Keep in mind that (aparrently) the reported focal lengths of the fresnels are not exact, and you'll want to leave the door open for adjustments here.
You might also want to check out this post I made a while ago...
If this doesn't answer your questions, it would probably be good to post them into that thread...
OK, dimensions...
An "unsplit" design is going to be the easiest to figure out, and it'll give you a better picture, but keystoning isn't easy.
You'll want some play or leway with all these, so be prepared to move them around...
Well, the distance from the bulb to the first fresnel (the collimating fresnel) is easy, just use the focal length of the fresnel (220mm). This distance has nothing to do with the projection, it is only the most efficient distance to gather light.
After that, you want to leave a little space between the collimating fresnel and the field fresnel, this space will help reduce "rainbows" and other arborations you want to avoid, it'll also let air move between the fresnels for cooling. After the rest of the dimensions can be estimated with the Focal Calc II. Keep in mind that (aparrently) the reported focal lengths of the fresnels are not exact, and you'll want to leave the door open for adjustments here.
You might also want to check out this post I made a while ago...
If this doesn't answer your questions, it would probably be good to post them into that thread...
Just a few updated questions-
With my lexan sheet, how thick does it need to be? I seem to think I read 1/8", but that might have been for tempered glass. Anyone know the desired thickness?
-With the mount for lexan/fresnels/lcd etc., are those usually pieces of wood with a slot routered out, or two separate pieces? Just wanted to get a hint on the construction of that. Also, should each optical component be free to move and adjust individually, or does just the whole optical assembly need to be movable?
-For the focusing of the triplet lens, I have seen people mounting with some sort of drain which allowed them to 'screw' the triplet in and out of focus. What is this piece and how should I go about using it?
thanks!
With my lexan sheet, how thick does it need to be? I seem to think I read 1/8", but that might have been for tempered glass. Anyone know the desired thickness?
-With the mount for lexan/fresnels/lcd etc., are those usually pieces of wood with a slot routered out, or two separate pieces? Just wanted to get a hint on the construction of that. Also, should each optical component be free to move and adjust individually, or does just the whole optical assembly need to be movable?
-For the focusing of the triplet lens, I have seen people mounting with some sort of drain which allowed them to 'screw' the triplet in and out of focus. What is this piece and how should I go about using it?
thanks!
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