So I am finally starting on a more official build of my projector. Version 1 was basically a thrown together contraption simply to determine if the idea would work. After ripping apart a partially broken old lcd that I had and an overhead projector that I acquired I came to my surprising conclusion... IT WORKS! So now that I have tasted the diluted potential of these lcd projectors I am set on creating another one. Here is my supply list as of now:

Halogen Lighting from an old 2200 lumen overhead projector
400w Ballast with 65k MH bulb

Fresnel set and upper lens (I don't know if it is technically a triplet because there is only one lens) from the overhead projector
LL 15" standard fresnel set with LL triplet lens

Westinghouse LCM-15v5 with 1024x768 native and 450:1 Contrast Ratio with 16ms Response Time

2 120mm fans with a computer PSU to power them

Haas box made from plywood

Also using the GRANDTEC GVC-1000 video converter which allows me to input composite, svideo, and VGA and to switch between those inputs, outputting to my VGA lcd.

(I have plans to eventually switch to the X2VGA with composite cables running out of my Xbox and DVD player)


These are my current parts, but that is simply because I have this overhead projector with lenses lying around. My plan is to make the box completely to Haas spec so that I can use the overhead parts, and then when I finally buy the LL 15" fresnels and triplet I can replace the crappy overhead fresnels with that. I also plan to eventually put a 400W 6500k Metal Halide in there with a ballast, but that will probably be the last step as my 2200 lumen projector is bright enough to last me a while. So thats the idea, and now im off to check the mail for my 15" lcd that I just ordered!

Welcome!

Thats a great choice in LCD. Take care of those FFCs.

I am doing the same thing with an old overhead and planning to replace parts later. I will warn you though. The lense you have now will disapoint you unless you understand how much better it will be with the LL one.

What is so bad about the standard overhead lenses? I have already built a really crappy projector (version 1) using the lenses from the overhead and it seemed fine. So I would be really excited if the LL lenses would make it better because I was not really expecting that much of an improvement from them...

So I just got the LCD screen in yesterday. It was extremely easy to strip thanks to a wonderful quide by ladieu in his PLOG. Here is a pic of the sub $100 refurbished monitor:

Never even assembled fully before it was taken apart...


Hooked it up real quick to test it out. Seems to be working fine.


Start the stripping!


Down to the good stuff after some annoying hidden screws


Quick question: Is that black film important?

I only had the panel stripped for around an hour before I decided to bite the bullet and go for the antiglare mod. I decided that water seemed like the safest route to go so I gathered my supplies and started pouring.

Too late to go back now


I followed ladieu's instrustions again and let it sit for 12 hours in total. Afterwards the evil antiglare peeled right off. Hardly took any effort at all. So here is a shot of the antiglare before I burned it and threw the remains in the garbage where it belongs:



And a nice before and after shot:

Before: Dull and hardly any reflection


After: Shiny as glass :-)


So now its sitting out to dry before I test out the results. I am still very interested in how the LL lenses will improve my projector over the overhead lenses I have now. One thing I have noticed that I hate is that the overhead lenses spread the image so quickly that the 8' by 8' screen that I have now cant be more than 12' away before the image overflows the screen. Hopefully the LL lenses are more of a longthrow than what I have now...

If you're unsure about the throw length, have you tried using the Focal Calc to compare the difference between the projection lenses? If you put in all the dimensions you were using previously with your OHP and check the box for projection lens, it will fill in the proper focal length, and then you can put in your new focal length of the LL triplet (320mm) to see which will give you a longer throw.

Even if the LL triplet has a shorter throw than your OHP lens, you should still notice an improvement in image quality, since you mentioned that your OHP was just a singlet lens, so don't be too bummed if you can't scoot your new projector back further than your last one

Yeah I checked the calculator earlier, and it doesnt look like the LL lenses will really change the throw by that much... maybe like half a foot or so. Any ideas about how much better the quality will be for the image with the LL lenses? And also, does anyone know about the GRANDTEC GVC-1000 video convertor that I am using? I keep getting the feeling that the video convertor is a culprit of the quality loss...

Either way, I will try to get some pics up tonight of how the screen looks being projected by just placing it on the overhead where a transparency would normally go. And don't worry, I will be sure to cool it with some fans so that there is no overheating or burning of the lcd panel.

Here are some shots of how it looks on a white bedsheet. Not too shabby but I definately need a brighter light engine. Cant wait for that T15...

The famous flower woman


A close-up of the colors


Pretty good detail for this early in the project


A close-up of the nose

I will probably be building the Haas enclosure and mounting most of the lenses this weekend over Thanksgiving. I just have to make sure to make it to Haas spec so that I can use it with my OHP lenses now, and still have it work with the LL lenses later. When I get back from break I will also be gutting the OHP and putting the lighting in the box. Its pretty bright and gets the job done for now. I like the fact that this whole project has cost under $200 so far (OHP was free). I almost feel bad spending more money on it because LL does sell a projector now for $500, so if I start to get close to that cost I might as well just bough one of those beauties. I'll make sure to get some pics up when I get back of the progress!

I got the wood tonight and I plan to cut it tomorrow at sometime. Wood is damn expensive though! I got veneered MDF a little less than an inch thick for the sides and some of the same stuff, but thinner, for the top and bottom. It cost quite a penny. Definitely shot up the total cost of the project. Now, its time to start drawing out the plans...

So I got a lot done over the Thanksgiving Weekend. I got all six sides of the box cut and now they just have to be reshaped a little and screwed together. The two sides with rounded tops and bottoms will have to be bandsawed and routed when I get back for Christmas Break. The inner frame for the LCD panel is also now entirely done. The bottom piece where the FCC's run took particular care but its all ready to get screwed together around that 15" beauty to protect it. I think I will also follow the idea of a lens holder that can be dropped in and taken out easily (Haas' original design). I think that would make tweaking and potentially reassembling later with new parts and lenses much easier. Here are a few pics of the progress:

Here is the bottom piece of the LCD frame I was talking about. Hopefully this will protect the panel a lot better than how it is now.


And here are the shots of all the pieces. You can see the thin top and bottom pieces that will be bent around the sides, as well as the front and back pieces where the fan and triplet assembly will eventually go. I also picked up the dowels from Home Depot.


When I get back from college for the Christmas break I will try to at least get the box completely done so I can start gutting the OHP.

Quick question: how do I change the subtitle for my topic so that I can keep that up-to-date?

Go to your first post in this thread, and click edit, then click Full Edit. You will then be able to edit the Topic Title and Topic Description, at the top of the edit screen.

Good luck on your PJ.

Thanks - that had been bugging me for months too!

Yeah I tried that originally and it still doesnt work. I dont see anywhere to edit the titles, just the text in the first post.

Click on the first post "edit" button. Then click "Full Edit"

Then look at the top of the page. The topic will be at the top and you can edit it.

I think you just might have missd it .

Webtek,

The lens you have may work just fine. Can you post a pic? The lens I had from my 3M 9550 projector did not have a wide enough field of view. I could get a really nice image on the wall, but the corners were dark when viewing 4:3. When I swapped the LL lense I ALMOST got rid of the dark corners. They are close enough now that only with a solid color across the whole screen can I see the difference.

The pics of you results look great by the way. It looks like you have some experience with wood working. I might have to copy your piece for the bottom of the sled since we have the same lcd. Keep us posted.

Ok so I tried that again and still nothing. I have done this before on other forums so maybe there is something wrong... Here is a screenshot just so you know what I am looking at:

man i got that same problem. was thinking it mite be my browser but dont really know im useing opera. Ill try fire fox in a minute. BTW every one was telling me the same thing they told you but I stilll didnt see anything there. My page looks just like yours with nothing to edit the topics on top.

I think it has some thing to do with the rich text editor>> just pmed you ok..
OK I got mine working it was just the browser so i used another (mozilla).

I just tried it in IE 6.0, Firefox 2.0, and Opera 9.0. None of them worked. I see the same thing for all of them. I think it may be something deeper than the browser. I will try enabling rich text though.

I tried some more rich text and browser tweaking and Im still getting nothing.. Any more ideas?

Ok well I am still having no luck at being able to change the title or subtitle for this PLOG, but anyways, on with the project! So, I totally gutted my overhead projector today and I have it in pieces. I am able to remove the bulb and socket assembly, but what else do I need to keep from the guts. I want to wire up my own switch, but there appears to be something that resembles a coil ballast. Will I need that to go from 120V household voltages to the correct voltage for the bulb? What else do I need to have, or can I just connect the 2 pins directly to a 120V outlet with a switch in between?

And here are some pics just so that you know what i'm talking about:

Here is the whole contraption


The two bulbs that I will use... I may actually try to use both at the same time. We will see.


And finally the ballast-looking thing


Any suggestions on what I need to keep? Or should I just wire the bulbs to the wall?

I looked all over and could find no information on google about the innards of an overhead projector and what the different parts do. I still have no idea what those big pieces are. From looking at other OHP lcd projectors, it looks like most people did have some large item wired with their OHP bulbs that looked similar to the ballast-like thing that I am talking about. I guess I will just try to include it because if it worked originally, why change it? It will also be good because if I do switch to a MH setup I will already have a place for the ballast. There are still a lot of extra wires for things like light settings, fan speed, and some other worthless stuff that I dont need. Ill have to deal with that later. I'm guessing its gonna be a lot of trial and error.

Dam i cant belive those options didnt work... wEll i got another Idea in opera go to view then style and the only thing that is checked marked should be author mode leave that like that and check (click on) emulate text browser;this should change the way the whole page looks... now go back and edit your first post....


If that doesnt work you could try to start a new thread and copy and paste everything

if not give me some time and im sure I can think up something!

GRRRR. So thanks for the ideas JackyChan, but I am still having no luck with the title changing. I have no idea what else to try. Maybe I will make another topic in the general discussion and see if I can change it there.

But back to the project, I am still working on figuring out what all the wires do in the OHP. Are they the same connections as with a MH ballast because they look like they are similiar...

Well, I have been doing a lot of planning lately so that when I go home for Christmas break I will be able to start on this thing right away. Here's the components I still need to get:

1. 4" inner diameter PVC connector of some sort to house my singlet lens in
2. VGA gender changer for VGA input on outside of box (on the way)
3. A couple 120V 250W ENH bulbs
4. Household dimmer switch (for dropping the voltage going into 120V bulbs = longer battery life)
5. Either a 15amp slow blow fuse with holder or a 15amp household breaker switch
6. 2 DPST switches rated for 120V
7. AC plug (no idea where to get this besides gutting another power supply)

That should be just about everything that I foresee needing at the moment. I think I may be going more for a bakery style projector because I am finding there are a few too many problems with bending the wood that I have to make the curves for a Haas style. I threw together a quick paint drawing of the circuit I am planning on making. It will allow me to have a main power switch that will allow the fans to turn on if it gets too hot (via the thermostat), and a secondary switch for the LCD and bulb. Also, a 15amp breaker will allow me to quickly reset the circuit if something gets crossed. It also saves money on blown fuses. Here is it:

Ok, so one quick question: If I use the circuit posted above can I drop down to a 5amp fuse instead of the 15amp breaker? I noticed the LL kit ships with a 5amp breaker so I figured I should stay to spec, but will the ATX power supply draw too much current?

Ok, well I have got a lot done over the past few weeks. I have been doing a lot of construction on the box itself and I decided to go with a somewhat simplified version of the Haas style using 3 different flat panels instead of a curved piece. The reason I went with this is because it allows me to easily work on either the front or rear sections without taking the whole top off. It also cuts down on a lot of the stress on the box. I still have to figure out how to cut out my 4" holes for the two 120mm fans and the singlet in the front. I really dont want to buy a core drill so maybe I will find a simpler solution. I ended up going with a 10amp fuse for the circuitry. Hopefully, the ATX power supply that I will be fitting in the box somehow will not be drawing too much amperage.

15A is very high. 10A is also very high. Your ATX power supply should not use much more power than what is connected to it will use. I measured the current used by my complete projector a few weeks ago and it never got over 3.8A (and I use a 400W lamp). Don't use a too high breaker because if there's a problem in your box, you want it to open and stop the projector.

Just check what is the maximum power output of you power supply and divide by its input voltage (120v in NA). You get the max amperage it will be able to drive (your fans total power must be lower than that). If your fans use less, you can use that number instead. Add that to the current drawn by all things connected to you source (lamp (250W/120V=2A, LCD (specs)). Add a 25 to 50% margin for the rating of your breaker and you'll be ok.

I don't know if you have experience with electricity but if not and I wasn't too clear, don't hesitate to ask for clarifications.

Well, I have made a ton of progress over Christmas and New Years break. I still cant get the stupid topic title to change, but if I could I would have to remove the Haas box from the title because I decided to go down a little more unique route partially due to the supplies that I had available to me. The wood that we had to use for the tops and bottoms of the box was 1/4 inch thick piece of wood that was having great difficulty bending. Instead of forcing it into a tremendously stressful position by holding it with the sides of the box I decided to change the design of the box to suit my materials. Instead of having one large piece that curves around the bends, I separated it into 3 flat sections, that together would make the same bend, just under a lot less stress. It also allows me to work on individual sections without having to take the entire top off, because any of the pieces can slide out without having to take the other pieces all the way off. So, for example, I could take off the back section to change out the bulb, instead of having to take the entire top off. It also made the slots much easier to cut because I could just use my table saw instead of worrying about a router and a guide for it. Here are some pics of the box coming together:


After putting in the dowels and screwing the whole thing together. Seems to be very sturdy.


Just another angle.


With the panels on.


Here's a close up of how I designed it so that each of the panels could slide off on their own. It also means that all the pieces just slide in easily; no stress. I just had a bad feeling about bending the wood under that much stress. This makes me feel much safer inside. After all, we wouldn't want all those lenses and lcd panels falling out the bottom if it snaps in half.


And a shot from above.



Now its time to start on the wiring as both of my huge 120mm fans have arrived and my switches are finally in!

to change your post description go to the first post in your plog

then change your title or description

sorry i didn't read all of your earlier posts, thats weird that you can't change the title?
nevermind my last posts.

by the way nice looking build so far

Well I couldn't wait with these pretty fans sitting here so I ran to Home Depot and got some nuts and bots and then dusted off the jigsaw. I made two holes in the back for the 120mm fans and then one central hole for the switch panel. I am following the diagram I posted earlier, so I will have a main power switch that turns the fan on, and then a second one which will turn on the LCD and bulb. I also ordered a male to male VGA gender changer so that I could mount that on the panel allowing me to run a VGA cable from that to the LCD on the inside of the box, as well as run a longer cable from the output on the outside of the box. It also looks pretty slick :-) Here are some pics with the fans and panel in place!




The back with beginning of the wiring

And of course I had to wire it all together real quick so that I could test it.

So here is the wiring mess beginning:


And getting worse...


Testing...


One light thats good!


And the second! It works!!!

And here's where I will end today. I tidied up the wiring A LOT and added a heat shield for the lamp. All the wires that have to go to the front will be run underneath it. You can see the dimmer that is in line with the light that I will use to regulate the voltage from 120V to whatever my bulb desires. The third heat shield panel will be added eventually, but not until everything is in place and bolted down. And of course, pics!

I added the lines for the bulb and started testing how much the dimmer changes the voltage to make sure that it would be appropriate for my 86V bulb. I put the ATX Power supply and LCD power supply where they will end up, but I can already see that I will have to figure out a good way to run all the wires to the front of the box so that they do not interfere with things.

Testing the voltage


You can also see here how that back heatshield is bowing from all the wires that are pushing against it. I will have to clean that up a little more eventually. Maybe I can tie some of the larger wires down to the wooden frame so they aren't such a hassle. I was already planning on doing that with the VGA cable and the Power Cables.

WOW! Very nice work so far, you should be proud. I especially like how you made the top for the panels to slide off and on. Cant wait to see more!

I have a theory you can change your topic names at ~100 posts... I can't change mine either.

Haha, yeah well that might be it. I was almost going to start another topic just because of how much has changed, but here's to hoping that it's 50 posts cause then we're both almost there! Let me know if you figure it out. And back to the topic of the projector, I have started planning the building of the LCD and fresnel frame so hopefully I will get to building that soon. I already have the LCD frame done, but I just to make slots for the fresnels and finish cutting the sled that they will both attach to so that they can slide in and out. I am also planning on using the standard gravity method for my front fresnel keystone adjustment. It seems to be the easiest method and provides pretty good results. I have also now cut the holes in my top piece where the air will come in and flow over the LCD to keep it nice and cool. I used a series of 1/2 inch holes in a line. Should be good enough and supply lots of air flow.

WARNING!

I'm not completely sure about this but if I remember correctly, it's NOT a good idea to use a dimmer to reduce the voltage on your lamp. A dimmer doesn't reduce voltage as you might expect. I don't remember how it works exactly but I know you will still have higher voltage peaks to you lamp. You voltmeter is just giving you the "average" voltage it sees.

If you want more details on this, let me know. I just thought I would warn you as soon as possible. I don't know how your lamp will react to this. It may be able to absorb it, but it may reduce its life. Or it could just burn out.

Depending on the bulb the dimmer might not survive the initial start pulse also if it does work the lamp will be very sensitive and probably shut off as soon as you start using it.

Can you guys explain this a little more? I actually heard and read about other members on this forum who did this. That's where I got the idea from. Why is it a bad idea?

First, I don't know how much you know about electricity so excuse me if I explain things you already know... or go in too much details.

Also let me say that I don't know how an ENH bulb works. I don't know if it needs a ballast (like a neon or a pulse strike bulb). If it does, it's a different problem alltogeter... But for my explaination, I am assuming that it doesn't.

Your power input is 120 volts AC (alternating current). That value is the RMS value (or effective voltage) The voltage actually oscillates from 170 to -170 volts. A 120V bulb can actually withstand up to 170V peak voltages.

A dimmer doesn't reduce the overall voltage wave. It cuts the voltage output to 0 volts for a certain amount of time throughout each wave cycle. This gives an overall RMS value (sort of an average) that is lower than its input but still having peaks from the input voltage.

Here's a crude drawing of what I'm trying to explain.

Click to view attachment

On the first wave, the RMS voltage is 120 volts (RMS is not the average voltage but something close to that). On the second wave, the RMS is lower, maybe around 90 volts. The average voltage is reduced but there are still peaks up to 170 volts. Your lamp may be able to take those voltages but if it's rated for 86 volts, it's peak maximum voltage would be around 120 volts. That means it's not intended for 170 volts peaks and that could reduce its life or simply burn it out. In extreme cases, it could even explode.

By the way, an AC voltmeter gives you the RMS voltage.

I'm not an expert on dimmer. I learned this in school many years ago so I may have forgotten some things here and there (or I may be completely rong also ), but you may want to verify this before using your circuit.

Hope this helps and I didn't confuse you too much. Don't hesitate to ask if something isn't clear. I'll be happy to help.

Thanks very much for that info. I definitely did not know all of that. The bulb I am using is a 120V bulb so I don't think there is anyway that the voltage could go too high to hurt it, but the sudden lows sound like they may be a problem. Should I just take the dimmer out all together and let it run at 120V? I had heard that by dropping it down a couple volts with a dimmer that you would increase its life span by almost double. Is that not true?

I need to correct my previous statement i didn't realize that you are using a halogen bulb. In this case a dimmer might work.
Bine is right thought most dimmer affect what is called the duty cycle and many motor controllers work the same way.
Im not sure if will work but i don't think that you will hurt any thing either by trying.

As far as I know, dimmers can be used with halogen lights BUT it won't increase its life. In fact, it will even reduce it. But not for the reasons I stated above.

Halogen bulbs have a filament that releases carbon particles that float around and sticks to the inner glass. When at full voltage (and highest temperature), the carbon somehow gets back to the filament. When dimmed, the temperature doesn't go high enough and the carbon stays on the glass and that will reduce its life and brightness. If you use a dimmer, you must put it at full power once in while (I've read 1 minute for every hour) to heat it enough to rerelease the carbon from the glass back to the filament. That may not be practile for a projector...

Also, dimmed halogen light are very yellowish which won't be good for projecting. I've read around here that even at full power, halogen is not the best light that can be used because of its color.

Yes halogen are always alittle more yellow you really want white light for nice colors.