When you frame the fresnel lens in an enclosure, do you put regular glass on both sides of the lens within the frame? Do you need to frame the lcd, and also enclose that in glass? If so, what are the dimensions of the fresnels (I bought mine from the Lumenlab Store) and the LCD (a pre-stripped Samsung from Techbench)? I want to start planning some frames and slot positions in the box so the frames slid nicely in place.

try something like this.

http://www.lumenlab.com/forums/index.php?showtopic=803&hl=

Thanks! Did you put your LCD in a frame as well? I just ordered the Samsung 15" Complete TV/LCD Kit from Techbench so I don't know if it is necessary...

i mounted mine back in the alumn frame it came in so i already would have predrilled hole in it to mount.

Cool. I think I am going to put rails on the sides of the inside of the box to drop all three frames in. This would let me slide them in and out if they needed to be replaced, or if the glass needed to be cleaned. I know that would work with the framed fresnel lens but I'm not so sure about the LCD because of the necessary wiring.

bamdiesel77,

You can make rails for everything; however, do "not" slide the LCD in and out of the box... You need to be double careful with your edge connectors. Those thin FFC's at the end of your glass LCD connect to the edge connectors. If you tear or break off one of those flat flexible cables you will cry a river.

Cheers,
Lee

If you make the front and back freznels removeable, it will give you access to the LCD for cleaning (without having to remove it) -- I'm trying to devise some type of "rail system" as well so I can gain access to both sides with my little computer vac.

I live in a fairly dusty environment and I think periodic cleaning is a necessary thing to consider in the design -- mainly to maintain the highest picture quality.

If we are "stretching" a row of tiny pixels onto a 10' screen, I shudder to think how big a single cluster of dust and pollen will be at that magnification.

~DM~

do the fresnels have to be framed or can you just mount them with pins and such... i haven't ordered my lens kit yet.
i thought the tempered glass was the only glass i needed to get cut.

The solution of choice seems to be to mount the rear freznel to the NON HOT (AWAY FROM BULB) side of the tempered glass with clips and/or to build a frame to house them. Same for the front freznel, only you can mount it on non-tempered glass. Mounting the freznels to the glass adds stability and protects it from scratches on one side.

There have been many solutions depending on your relative woodworking/crafting skills. Simple works, but if you want/need stable internals it's best to frame them, especially the front freznel so you can adjust for keystoning.

~DM~

Can you do this...

Have tempered glass, unframed, slid into a groove on the side of the box, or a rail (not sure where I can find such a rail and what it would have to be made of)... then have your first fresnel, framed on both sides by normal 1/8" glass using 3-channel aluminum. This would also be slid into a rail system as well. It would be followed by your uncovered LCD panel, and then another fresnel, enclosed with two pieces of 1/8" regular glass in a frame and rail system. Are all these glass pieces necessary or am I overdoing it? I basically want to avoid scratching the lens and also have the ability to clean the surface (dust might be a problem as mentioned earlier in this forum). It is going to be tricky because the box I have been constructing is 14 inches wide internally. The lens is 12 inches wide, and that leaves only 1 inch to work with on either side, but I think it's still possible to do it.

Where has everyone you has built these frames / rails got their materials in the past? I went to Home Depot and they had no aluminum U-channels that could be used for framing. Would I have to go to a specialty store to get these materials? At least with this I know what I need... the rail system is a different story...

bamdiesel77,

i to had looked at home depot. i found fine at my local hardware store for approx $10.00 per 8' leanth. i used 1 pair to slide my rear fresnel into, sandwitched between the tempered glass and a piece of regular glass to keep it clean and flat, with brains binder clip method to hold it together. i used the second set to slide the metal casing of/ and lcd into. fit right in tight. for my front fresnel (keystone setup)i lined it up on a piece of reg. glass, groove side twards glass, and siliconed it carefully in place. keeps it clean as well. regular glass cost me approx $2.00 per piece.
toby

Hmmm, I bought mine at Lowes, but I know I've seen them at Home Depot too. In Lowes they were located in the section with the screen door and screen materials. Try checking around ther at HD. Good Luck!

I found aluminum u channel meant for capping 3/8" plywood at Lowes in the hardware section in the bins with the pieces of threaded rod and other pieces of metal. I have not tried to use it yet but I think it will work well. And by the way, hello everyone.

Hi davidcb, welcome to the boards.

I haven't started building my box quite yet, but I was just planning on routing out some of the wood on the sides to have my glass fresnel frames just slide in, with no extra hardware required. I'm assuming this would work fine, any disagreements?

Hi all,
I also wanted to make the frames for the lenses like Joe2000chevy did.
But now he tried it without the glass and got a much brighter picture!
check -> another lumenlab projector
after reading this I'm not sure what to do.
Any suggestions??

thx

I hadn't heard about that. I am just building my frames now, with some glass already siliconed into wood. Maybe I'll just do one piece of glass for each fresnel to just protect the side with the rings.

im sorry if this is a very simple question:

i just received my fresnels in the mail and i just want to know if they are different... i cannot tell which is which... 220mm and 330mm?

please help,
-joon

Find an overhead light. Hold a lens groove side facing down and raise it off the floor until it focuses to the smallest point it will make. Do this for both lenses. The lens that focuses closer to the ground is the 220mm.