Hello everyone. Some of you may remember me from before. I built a 15" projector back in 2004 and have been relatively inactive ever since. I have decided to move on to bigger and better things: A 17" SXGA pro lens vertical projector. Here are the parts I plan am using:

- Samsung 740N SXGA 8ms 600:1 LCD. I chose this LCD because of its high light transmittance, which has been measured at 8.5%. (212.99 from newegg)
- Unsplit Pro Lenses for more even light coverage and focus. (249.97 from lumenlab)
- Plywood box because MDF is too heavy, and lacks the strength of plywood.
- 2 PCAC cooling fans. (27.98 from lumenlab)
- Pulse Strike T15 Lamp with electronic ballast (I had the electronic ballast from before. Lamp was 59.99 from lumenlab)
- Front surface mirror (33.99 from lumenlab)
- Pro Reflector for extra-bright projections (14.99 from lumenlab)
- 120mm fan grill to (maybe) mount the Pro Reflector on (1.99 from newegg, but they raped me with $4.99 shipping )
TOTAL: $601.90 + Shipping and Taxes

I ordered my parts today (2/19/2006).

For design, I am obviously going vertical with one fold as stated before. The support structure will use the picture frame + threaded rod style. I will have a light box to hold the bulb in.

For focusing, I plan to use a threaded-rod design as well, so I can fine-focus with the turn of a knob. Adjustability will be key in my design, so that I can fine-tune my picture as much as possible.

I am hoping to have this whole thing up and running by april fools day!

I will post some design pictures here in the next week or so. I need to draw them first

Thanks for the great support and wealth of information. The community really makes this site!

Thanks,
Nick

Okay, I have come up with a plan to cool this box. I will completely isolate the top half of the box (containing the LCD, fresnels, and pro lens) from the bottom half (lamp) using a sheet of tempered glass and wood. The seal will be fairly airtight.

Each cooling zone will have 1 PCAC fan dedicated to it, one for the lamp and one for the LCD. In this way I will stop the rise of hot air from damaging my fresnels and/or LCD.

In addition, each cooling zone will have seperate air intakes. The top LCD zone will have air intakes around the LCD on either side, and the bottom zone will feature one air intake covered by louvers on the opposite side.

The sheet of tempered glass is recycled from my old projector, and is fairly large, so there will be minimal loss of light. I will place a UV filter cut to size over the tempered glass to save my LCD/eyes.

How does this cooling plan sound? I will post some design pics later to help visualize.

Nick

Sounds good.

Okay, I spent the last three hours making this in AutoCad. It is a fairly precise right side view of my projector. Not included are: air intakes, measurements. But just know that I am using the pro lenses. The distance from the forward fresnel to the triplet is precisely 650mm and the LCD moves up and down to focus. The rear fresnel is also fixed at 220 mm from the bulb.

The $64,000 question: How do I cool the LCD? I was thinking of routing some air vents into the side, so that no matter what the LCD's position is, there will be a slight breeze. Or, I could force the air to move across the front, but that would be difficult.

Note: The power circuitry of the LCD is completely seperated from the bulb's power circuitry. Hopefully this will help with interference, as SupraGuy had some real problems with this panel (740N). I still decided to order it because of its 8.5% light transmittance.

Please let me know what you think of my design!

Nick

I would suggest that you move the upper PCAC above but close to the LCD you want to draw air across the LCD everyting else doesn't care aboit temps too much so put your cooling where you need it.

how tall is your projector?

I know with my vertical projector i have to have a 10deg tilt to the triplet to be able to keep the projection off the floor.. my triplet is about 25" off the ground and has a 10deg tilt and the projection is only about 14-18" off the ground.

Be sure you have taken this into account..

I have revised my design so that the upper PCAC moves with the LCD, and always blows air directly across. I also added air intakes in blue. Lastly, I added 1 80mm fan to prevent the upper ambient temperature from getting too high.

Also, the bulb is now perpendicular to the LCD.

Unfortunately, the farthest my LCD can be from the triplet now is ~619mm. This means that the greatest distance the projector can be from the screen and still focus is about 8.75 feet.This should be a non-issue though, because I plan for that distance to the screen to be roughly 10 feet. If it ends up being too short, I can always put the triplet on a threaded rod-knob-keyboard slide system like the LCD so that I can extend that distance, while only making a minimal sacrifice in brightness.

Here is my revised design:




From the bottom of the projector to the center of the triplet is rougly 31.75". I have a stand which I will put the projector on to ensure it is at the right height.

Well, my first item came in the mail today, and it's very exciting. Just about as exciting as a 120mm fan grill can get. The ironic thing is that I ordered it from newegg.com thinking it would come in a small manilla folder or something. Instead it came in a roughly 1 cubic foot box, filled with packing peanuts. As if something like this is going to get damaged.

Nick

now u know why they charged so much for shipping...

My thougts exactly. I was wondering why they were charging me 4 bucks to ship a 99 cent fan grill.

Nick

I think you may want to redo your cooling you have two inlets, two fans one effectively being an exhast. With more than one fan and inlet I fear that you won't be able to move air effectively I would keep the lower inlet (possibly making it bigger and move the left side fan to the top so air moves right to left bottom to top to ensure that air is going in one direction.

Edit: I decided to resort to a more standard cooling solution. The dual chamber idea sounded cool, but I think it will prevent the kind of adjustability that I want. That pane of glass and board of wood will still be there above the lighting area, but there will be gaps on either side. Then I will just move the 2 PCAC fans right next to each other, eliminate the very bottom air inatke. This will make the only air intake the one directly near the LCD. Using this method, I hope to pull even more air directly across the LCD.

Nick

My monitor came in the mail today. I have yet to detect a dead or stuck pixel. I think I was lucky with this panel. Here are a few pictures:

Just in case you didn't see above, this is a 740N. I will strip it down today or tomorrow.

[img=http://img140.imageshack.us/img140/2751/740nfront9mu.th.jpg]

[img=http://img50.imageshack.us/img50/4470/740nback6bp.th.jpg]

[img=http://img140.imageshack.us/img140/3166/740nangled4zu.th.jpg]

Nick

I have successfully stripped the 740N. It's ALIVE!!

Here's a picture. One minor concern: There are extremely small edge connectors along side. They are so small that they shouldn't be a problem, though.

Nick

Are you going to attempt an AG removal?
If you do,please post the details.Thanks!

No, I do not intend on doing an AG removal. I know the process is rather mainstream these days, but I can't afford to loose this LCD (literally).

Nick

I have a 740N also and am going to strip it soon once I get my parts from LL, so it's reasuring so see somone else successfully strip it before I attemt to do it

Nick & Steve - There are some folks over in another thread looking for 740N owners. They're getting differing transmission readings between their 730Bs & 740Ns, which they assumed to be (optically) identical.

They were starting to swap Model Code, Serial Number, and Manufacturing Date & Location. You may be interested in what they're talking about, or have some data to help them out.

"LCD Transmission Measurements, the puzzle deepens - A Tale of 3 Samsungs"

In case I screwed up including the link above, here's the thread info:

Premium Forums->Projector Builder Subforums->Intelligent Video Projector Design
"LCD Transmission Measurements, the puzzle deepens - A Tale of 3 Samsungs"
starting with meyer2's post #114,

(I'm posting this as one who is zeroing in on an LCD purchase, and the 740N is about at the top of my list).

Mike

I have seen this thread. I would gladly buy a lux meter to test, but I have no idea where to buy one. Any suggestions? Also, see this stripping guide I posted. It describes how I stripped my 740N.

Thanks,
Nick


--740N STRIPPING GUIDE--

I sent this to steve_TO and he found it useful. Hopefully anyone using the 740N will agree.

To begin, I first unscrewed the stand from the main monitor. Then I took a small flat head screwdriver and pryed the back panel from the front panel, starting at the top of the monitor. When you hear a large click, that is a good indication that you have partially seperated the two halves.

Run the flathead screwdriver along that seam until it is completely seperated, then put the monitor facedown on a flat surface. The back panel should lift off.

Next disconnect the backlight (pink and blue wires, there should be 4 connectors) and the small gray strip of wires, which lead to the control buttons. I just pried the control buttons off the front of the monitor.

Next I seperated the LCD module (with backlight and all) from the control circuitry. If memory serves, it just lifts off.

At this point, you will see a bundle of wires going from the LCD to the control circuitry . Unplug it from the CONTROL CIRCUITRY (not the LCD). You might want to temporarily disconnect the control circuitry from the metal casing for easy access to that connector.

The LCD module should be free from the control circuitry now. You will see a white backing with the FFC connectors looped around. There is a plastic covering over the FFCs. Carefully seperate it.

Next is the trickiest part. The FFC board is attached to the backlight assembly via an EXTREMELY SMALL phillips screw. I had to use a tiny phillips head screwdriver to get it off. Fortunately, it wasn't very tight. This should free the FFC board.

Here is a picture of the problem screw next to a penny:


Next you will want to remove the metal frame. You will notice that along the edges, it is sort of clipped in. I just pried at these key locations and the thing slid off with a little force. All the while, be careful not to stress those FFCs too much, they are very fragile, and if you tear one, it's bad news bears.

At this point, I am pretty sure the backlight assembly just lifted off the LCD, if memory serves.

Volia! The panel is exposed. I hope this guide helped.

Nick

Great work Nick!

tried to fix the broken ebay links....

in case you don't see the reply on light meters in the other thread:

try this link:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...=ADME:B:EF:US:1

or:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...=ADME:B:EF:US:1


or itemn #:
7592526196
or
7592967335

both bout 30-32$ $ shipping is 5.95 for the california one(which is the model at least 4-5 of us have), though you might double check to make sure that one is actually shipped form california, lucky_me bought one on ebay(same model) that shipped from hong kong, and on another note, it does actually help "fine-tune" my brightness especially the eveness....

if you read the other thread the sun test wuold be something you could do...we ALL would love to see supras transmission tests and results duplicated(as I'm sure you would like to know you have one of the most transmissive lcds around!)

and back on topis.... right now I'm in the middle of my 17" vertical build too...and the hard thing for me is figuring out where to mount the circuit boards..what do you have in mind? how big of a screen do you plan on projecting?

mikyd1954 -

I will see if I can buy that lux meter today.

My projected image will only be about 70" diagonal (only.. hehe) because of the long throw of the lenses. (Edited, 86" was a miscalculation. 70" might be too, but I think it closer to reality judging by the size of my room)

To mount the circuit boards, I plan on keeping all the circuitry in the metal frame. There are holes in the metal frame which serve no purpose ( I'm not sure why they are there, they are placed somewhat arbitrarily). I am going to put screws through these holes that go directly into the MDF, in several key locations.

Here's a picture of the circuitry so you can get a better idea:



Hope this helps,
Nick

so they will be mounted directly to the side of the pj on the metal ?...anyway I edited the post above because the links were broken, have fixed them now:
try this link:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...=ADME:B:EF:US:1

or:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...=ADME:B:EF:US:1


or itemn #:
7592526196
or
7592967335

Yes, they will. They will be screwed into a board of MDF, which will be able to move up and down with the LCD itself. In my design (borrowed from SupraGuy) the LCD moves, not the triplet. This is for the best possible lighting.

Thank you for posting those revised links. I noticed earlier that the others were broken.

Thanks,
Nick

Update: I have been working a bit over the last two days on my box. It is coming along nicely. I will probably start staining it next week and start mounting stuff inside after that is done.

Anyone who has seen my post in the help forum knows that I got warped boards from the home depot. Fortunately I have been able to (somewhat) correct this, and the box is coming along nicely. Here are a couple of pictures:

Note: I will remove the ballast and fans for the staining (and tape off the hinges and switches).

Nick

how do you plan to make the lcd sled moveable? looks like you and I are building the same one.... though your skills are probably better than mine at the wood stuff ... I was thinking for my moveable sled, maybe slots thru the outside of the box with some brass wingnuts(to go with the bombay mahogany stain) to tighten the sled down...though I hate to have any visible holes in the box ..

EDIT 2: Instead of having the LCD sled moving on a threaded rod, I have decided to support it just like I am supporting the fresnels: on the threaded rod system. Why did I make this decision? Well, my projector is going to be in the same place for quite some time, and being able to focus it on the fly (via a knob) is not a priority. By putting it on the threaded rods, I will have a somewhat more permanent solution. Also, the LCD will be supported at 4 points instead of 1, which will prevent my frame from bending or warping.

I will still be able to focus my projector, of course. It might just take a few minutes

EDIT: Your wingnut idea sounds good, but I agree, having holes would be a little annoying. Also, I would worry about light leaks.

Hope this helps,
Nick

yeah, sometimes I forget that its only going to be used in one spot, and at most 2 screen sizes, 60" and 84", the 60" mostly for when its daytime out and it needs to be brighter... and I had to laugh at your comment earlier about "only 86 inches"...someetimes I forget when I think about the projection only being 86" or whatever that I'm currently watching a 27" tv and have for years hey did you ever get your light meter? not sure if you read the lcd transmission thread, but it turns out that samsung doesn't neccessarily use samsung panels in its monitors...looks like Supras' is(8.5% trans) but aonther samsung is actually an AUOptronics panel....can you look at your part numbers(on the circuit board, the backlight etc) and see what they say? supra posted a pic of his backlight part number...

I don't want to beat a dead horse or anything Nick , but you could have bought http://www.newegg.com/Product/Product.asp?...N82E16811999204 Ten of these for 20$. Instead of one for 7$. It looks like everything is coming along real nicely, I envy your box, and those hinges that make it open so easily.

Edit: The AG removal really isn't that hazardous, only if you try to force it when it tells you no.

Litherish - D'oh! Didn't see the quantity discount. Damn. At first I thought you were going to talk about the 10 fans/10 dollars deal. I only learned of that AFTER I got my 2 PCACs. I appreciate the comments on the box

Also I like the "beat the dead horse" icon.

Mikyd - Indeed it is laughable that I say only 70". That's freaking huge! But compared to some other people on this forum who have 120" screens, it's not that big. It's all relative

And no, I didn't get the light meter. Unfortunately, I am already over-budget.. once my family sees my projection, which they will certainly be impressed by () I will see if I can talk them into getting a light meter.

I am currently away from my house. Once I get back, I will get those model numbers off the circuit boards.

Nick

Saddened to see my PLOG drop to the second page, I have decided to post an update. I would have had tons of progress with the projector this week, but I have gotten the flu. I will start working on the box again this weekend.

Nick

sorry to hear you've fallen ill. at least that gives you time to think and plan, if not build.

feel better soon!

Ok, I'm feeling better. But, I won't be able to make some serious progress until I get a week's worth of work made up, so stay tuned in the next week or so for updates.

There has been a request for me to post my AutoCad files, so here they are. They are pretty accurate, but I don't intend to follow them. Hopefully it will make some people's lives easier.

Nick

classic, a man after my own heart...if you knew how many plans I have painstakingly drawn(by hand and cad) and then totally ignored
I've discovered that DIY time comes in fits and spurts but eventually you'll get it done!

Hello, everyone. Finally it is time for a much-needed update. I can't believe my plog made it all the way to the 3rd page.

I have been working on this thing all week, but I have not had time to update my plog, namely because all my spare time was being used up by the construction. Fortunately, I have some pictures of the projector as it stands today. Enjoy.

[img=http://img130.imageshack.us/img130/1741/projectorfar2vt.th.jpg]
This is a picture of the inside of my projector. Things to notice: My threaded rods are attached, I have my light bulb enclosure complete. More on this later.

[img=http://img130.imageshack.us/img130/5448/lightengineclose4em.th.jpg]
Here is a closeup of my lighting enclosure. My bulb is in place, screwed into the mogul base, though you really can't see it. The pro reflector is mounted. It is difficult to tell from the picture, but the whole thing is sitting on 2 keyboard slides (one for each axis). This lets me move the whole thing left, right, forward, and backward so I can get the arc in the exact focal point of the rear fresnel.

[img=http://img47.imageshack.us/img47/8742/internalstop9ls.th.jpg]
This is the inside of the projector, from the top looking down.

[img=http://img47.imageshack.us/img47/827/lcdsled2vz.th.jpg]
Lastly, here is a picture of my LCD sled. One thing to point out is that I had to re-situate the display control board so that the cable from the panel itself can reach it. Hopefully the board's proximity to the power circuitry will not affect my image. Don't worry about me shorting anything, the power board came with a plastic sheet covering the entire thing.

That's all for now. Comments are much appreciated, as always. I hope you enjoy reading my PLOG.

Nick

Looks like a lot of wood very close to bulb. Are you going to use flashing???

I suppose I could. All the heat is obviously coming from the arc, and directly below that is the reflector. I am putting a fan which will blow a constant breeze across the arc, and the hot air will get exhausted out the back. I don't have any flashing, but I have heard that others have had success with aluminum foil. Maybe I should put some of that down?

Nick

Checking out your plog. Cool Cad pics and an interesting project. I will have to check on your progress. Thanks for compliments on my plog!

MoparCJ5's 15" Overhead Projector

Hello, Everyone. I have some great news: my projector is done. First, let me say that I could not have done it without the community helping me. Thanks everyone so much. Also, I made some revisions to my design. In my opinion, using threaded rods to mount the fresnel/LCD frames was more of a burden than a help. So, I fixed them in place and created a last minute-triplet focusing mechanism. Here are a few pictures:


Focusing Mechanism


My FS mirror actually snapped into 3 pieces when mounting it the first time. I was trying to use screws (not into the mirror, into the wood backing I put on) and the pressure was too great. It broke. However, one fragment was large enough to use in my projector, so thankfully I did not have to order another.


This is a picture of the triplet from the inside. Surprisingly, a lot of light is actually leaking to the sides of the triplet. I am very satisfied with my image quality (my digital camera makes it look abysmal, but it is actually really good) but I wonder about the wasted light around the triplet.


Random picture of my bulb in action. I added an 80mm fan to blow air directly across the arc. It seems to help with cooling in my box quite a bit, because it sucks in cool air from one side, the air gets heated by the bulb, and then it is exhaused out the of box by 2 PCAC fans.


Here is my first picture of the image quality. My camera makes it look pretty bad, but in actuality my focus is crystal clear (except for a bit in the lower left corner, but you can still read text). I also feel that it exaggerates any dimming of the corners that there is in my projection. I was actually very surprised at the even lighting.

Thanks everyone. I hope you enjoyed reading my PLOG. I will post more results at a later date, most likely in the next few days. It is important to note that I am projecting onto blackout cloth. At first, it was a plain white wall, but the image was very grainy. With the blackout cloth, it appears much crisper.

Nick

That looks really good. Love to see some movie screen shots.

Bluto

Thanks, Mr.Blutarski.

Edit: You can see how my eballast is currently mounted on the second page.

I have a question about the eballast. Currently, I have it mounted outside the box. There is no active cooling on it whatsoever. I ran my projector for about 5 hours straight last night, and there were no problems with the eballast overheating and shutting off. That being said, during that last hour or so the ballast became extremely hot. Too hot to hold your finger on for more than a second or so.

I have the first eballast sold here at LL, and the sticker on the side says the maximum temperature is 80c. I will take some measurements later to make sure that I am not exeeding this rating, but will the extreme heat shorten the life of the ballast? Better safe than sorry.

Thanks,
Nick

Here are some Half Life 2 shots. These are a bit more true to life, but the camera still makes the image look grainy and out of focus. The colors in these pictures are more realistic than the previous image posted. I set the camera to manual and set the exposure (I think) to 400. I will keep playing with my digital camera to see if I can get a clearer picture.





Half life 2 is absolutely amazing on the projector. I might get oblivion in a few days, if so, I will post some pictures of that. Also, I will have some movie pictures up tonight.

Enjoy,
Nick

Nice pics Nick!
Glad to see she is pefrorming well!
(My e-ballast is internal,with only a sheet of 6mm mdf between it and the lamp,no active cooling,and it runs and runs! )
Cheers P

Thanks for the compliments and advice, pun15her. Honored to have you post in my PLOG =D

I decided I will just keep the ballast where it is for now. If problems arise, I will put some sort of active cooling on it.

Nick

I could not resist the temptation. It was a thursday afternoon, with ambient light pouring in from that place they call "outside". After seeing countless successful AG removals, I decided it was time to do mine. I am doing a water-soak method, and I plan on letting it soak for a good 24 hours. Here are some pictures of the soak as it stands currently in my room:

LCD with paper towels and FFCs taped off:


LCD with the works (as it is now). There is a layer of plastic wrap to prevent too much evaporation directly over the paper towels, and above that a precautionary sign to ward off family members who might get a little too curious:


Hopefully all goes well. Updates soon, as always =)

Edit: I also figured out (and hopefully corrected) the reason why I was getting bad focus on the left side. My LCD tray (frame?) was not perfectly level. I re-aligned it, and I would test it with the LCD, but it's soaking right now. Tomorrow, if my LCD survives, () hopefully I will be pleasantly surprised by the better color and crispness (?) of the picture.

Thanks,
Nick

good idea with the sign. hopefully the panel survives

I put the same kinda warning sign up as you did. A word of advice, watch out for cats, and also, make sure you keep it damp through the entire soak, it's no good if you go to sleep and it dries out, keep that thing wet! (not too wet of course) And you absolutely MUST post comparison Half-Life 2 shots when you are done, I will kill j00 if you don't.

Yeah, I have had a strict "no cat" policy since I started the AG removal

And I will try to post some comparison HL2 shots. I can probably get an identical one for the first one (the citadel) but the second one was an action shot, so it might be a little harder

A little update on the AG: I set my alarm to 4:50 AM (12 hour mark) and tried to peel off the AG. I got about 1/5 of it off, in one corner, but it took some force so I cut off that section and am currently letting it soak more. Hopefully after 24 hours it will be nice and easy to peel it off, because it would really stink to have the AG only partially peeled off, though I really doubt that will happen

Nick

First, the good news: all my AG is off. And I got oblivion, its great, especially on the projector. My colors after AG removal are much, much more vivid. It is close to plasma-like vividness.

The bad news: I accidentally scratched my screen a bunch of times in the center trying to get the last bit of AG off. I was using a razor blade.. and I couldnt see the scratches in the still-damp screen. Upon drying, and to my sheer horror, I saw a bunch of scratches in the polarizer! Picture of the scratches:

I let the LCD dry for a while, and fired up the projector. It is still in perfect working order, but I noticed two things:

1. The scratches are extremely obvious in my projection. Not to mention they are all dead center (where the glue was by far the hardest)

2. I had let the middle section soak some more (most of it was off) and I soaked the polarizer a bit on accident... Now when my monitor displays all black I can see blue where the water got into the polarizer. And that part of the image is a slight bit brighter than the rest.

All is not lost, though. I am considering completely replacing my polarizer, either by re-applying a new one to the screen or going with the "polar bear" style polarized triplet. Any suggestions from people that have done this?

Thanks,
Nick