Hi Y'all.

It has been a lot of fun reading, experimenting and learning, so now it is time to start my projector.

I started with an OHP to see if I would be satisfied with the results before building a box and to get to know more about how things work in real life. I purchased a CMV 529a 15" LCD based on the good experience of others and rigged it on top of a 3M 9800 OHP. About 3/4" of the width of the panel was clipped but the results were good in a dark room. This OHP has 6000 lumens output but the image was way too washed out in daylight to be watchable in my family room.

Sincere thanks to the contributors on this forum for sharing your successes and failures. I have learned from both. Some of the designs are truly amazing! The consistency of results from all the different designs is what convinced me to give it a go.

First, the constraints. My primary viewing room is small, measuring 10.5' x 11.5' and is packed full of computers, guitars and sound equipment. This is where I work and play. The PJ will need to fit in without taking over. That is why I decided on the vertical.

The measurement from face to screen will be about 9'. I have already built a 64" x 48" (78" diagonal) black-out cloth screen and got good results with the OHP. I could build a little bigger screen but not by much. The screen takes up all of the room between my front speakers now. If the throw/diagonal ratio is about 1:1 then the front of the box can sit no more than 78" back from the screen which will put it in out in the floor a bit.

So I will need to move it back out of the way when other things are happening and occasionally I may want move the projector into the family room so it needs to be semi-portable.

The Box

I don't have any wood-working tools other than a power saw, jig saw and belt sander so I wasn't comfortable with a build-from-scratch option. Several years ago I purchased some modular shelving units that measure 32" x 16" x 16" which is slightly larger than the standard design so I began to visualize ways to build a projector using them. A floor-standing vertical could fit - and the folded design by Joe2000Chevy was just the ticket!

This is a modular shelving unit I bought many years ago. This one has seen some action as a computer stand but there a few others in the background that are in fine shape.

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The thought is that I could have a floor about 6" up from the bottom with the ballast and fans mounted there. I was also going to put a short shelf in the top chamber to mount the TVBox and DVD Player so everything could be moved as a unit.

Here is a PaintShop mock up of how the front will look.

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And the Back.

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Cooling?

The standard horizontal design has the fan mounted on the top/back and the slot opening to the outside on the top.

I am considering mounting the fan(s) on the bottom of the enclosure with a slot on the LCD tray opening into the top chamber which will not be sealed as in the standard design. Here is a not-to-scale diagram of how it might look.

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Personally speaking...
I think that is going to be one amazing looking pj.
I love the whole idea!
Good luck!
(BTW,It is worth it!)

Hope So! BTW, I followed your PLOG through the many iterations. Awsome box . . Wish I had the equipment to finish mine off that way!

What I have.

The innards are LumenLab Standard lenses and light kit, Ikea reflector and XL10 from IReplica. The LCD is the CMV 529a mentioned above. Other miscellaneous parts were scrounged from junk boxes around the house or purchased from various hardware and lumber stores.

I have an Avermedia TVBox 5 that I picked up w/ rebate for < $50 and a small DVD player that was < $40 from Best Buy. I know that they aren't the highest quality, but from my experience with the OHP they are watchable.

So anyone willing to offer any sage advise - - - bellylaughs - - - or warnings before I begin hacking the lumber and mounting the stuff?

Go for it!
Just close your eyes and put your foot to the floor!!

I am just curious about which side of the projector (front or back) you are exhausting the air out of. I don't think that it would be a real problem exhausting out the back where you pull air in from, but I see a remote possibility for the air to move in a circular fashion. For example, the hot air that is being exhausted and being sucked back into the projector making it hotter than it should be.

That is just something to think about. Also, if you exhaust the air out the front it might help to muffle the sound of the fan.

Exhaust is downward,into the empty space .A small "vane" encouraging the exiting air towards the front would direct the hotter air to exit in the desired direction,leaving the intake free of warm air,I think?

That was what I was thinking, or just closing off the back of that bottom space entirely leaving only the front open.

There should be some airflow in both the front and back at the top. Since it is 32" tall the heat may dissipate enough that it probably wouldn't matter. But I could close off either side if it is a problem.

Redneck CAD System

I drew out a 1:1 scale side-view layout of the projector on butcher paper today. Not as high-tech as others, but I needed it to help visualize how the pieces fit together and how cuts would need to be made.

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I am still working out the details of the optics tray. The Field Fresnel will be mounted in a screen frame and will pivot in the middle. I plan to use a threaded-rod attached to one end of the frame for Keystone adjustment.

The LCD will be mounted on a 1/4 masonite panel with a 9 x 12 cutout. This panel will butt against the back of the enclosure with a 1" gap in the front. I have the collaminator drawn in at the standard 5/8" from the LCD but it would really simplify the design if I could drop it back to 1" from the LCD. Then I could maintain clearance for airflow by mounting it on a 1/4" masonite panel with a 3/4" gap between it and the masonite the LCD is mounted on. This panel would butt against the front of the enclosure with a gap at the back.

So is the distance between the LCD and the Collaminator Fresnel a critical one?

Fan Test

I have been reading through the cooling thread for insight into designing the cooling system. The Series (Stacked) -vs- Parallel discussion caught my attention. I had planned on using multiple 120mm, 12VDC fans running at 7 volts hoping that it would be quiet and still have enough airflow.

So I decided to do a little testing. I have a DC power supply that is switchable 12V, 9V, 7.5v, 6v, 4.5v and 3v and I got a deal on 120mm fans so I bought 5. I cut two holes in a cardboard box and began adding fans. Closing the endflaps to various degrees simulated a restriction caused by a filter or small passage-way. The fans were significantly louder when there was a restriction.

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My very subjective opinion is that two fans running at 7.5v produces about the same airflow as one at 12v with about 1/2 the noise. Four fans running at the same time didn't sound much louder until they were stacked. It sounded about the same as when the airflow was restricted.


My thought is that I could go with all 4 fans at 12v and make the inlet opening a 1 1/4" round hole and my pj could double as a vacuum cleaner . . .

Nah! Two fans in parallel should do just fine.

Cutting Up!

Bold move today. I put down the pencil and picked up the saw. There was a recomendation in the reference section about making a saw jig. A piece of masonite screwed to a straight piece of wood and then cut off with the saw makes a timesaving fixture. Mark the board, clamp the jig to the mark and cut to exact size!

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Another trick is to score along the straight edge with a knife before cutting to minimize end splintering when cutting cross grain.

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Cheat Sheet.

A benefit of making a 1:1 scale drawing is that you can transfer the measurements straight to the work piece, or at least cross check once you have laid it out. Here is the markup for the floor of the light box showing the locations of the fans and MH bulb.

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What software did you use to make your design/layout

No software at all - - butcher paper taped to a table with a yardstick C-clamped along one side because I don't have a T-square anymore. Did all the drawing with a pencil and two triangles. See the post above for it all laying out on the table.

what about the cooling pic up above

That was done in Paint Shop Pro. I use it for photo manipulation and web graphics. It isn't very accurate for doing line drawings . . at least I haven't figured out how to use it for that.

Optics Tray.

Since the PJ is a vertical, I thought that a slide in tray for the LCD / Fresnel mount would be a good idea. I cut two pieces of masonite with a wood spacers. The spacers have a notch on the bottom to hold the Lexan heat shield and a groove in the middle for the rear fresnel. The notch & groove were cut with a utility knife. The two pieces on the left are the guides for the tray to slide in on.
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The tray is clamped together to try the fit with the fresnel (left in the wrapper) and the Lexan. This is the end that will be toward the front of the PJ.
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Here is the tray mounted in the box. I still have to make the mount for the front fresnel.

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It is starting to take shape! Here is an upside down view of the box w/ the floor and fans mounted.

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I am still thinking about how to mount the bulb and reflector. You can see how it will be oriented in the pic. Since I am short on tools, I have to MacGyver everything from loose parts. Anyhoo, that is the fun of DIY!

Fresnel Mount.

The front (top in a vertical) fresnel mount is made of screen frame. This shows the view from the back of the optics tray with the mount on top.

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The side view shows how much adjustment will be in the pivot point. After reading the "Keystoning" thread for awhile, that much adjustment may not be necessary or desirable. The doohickey attached on the right is 1/2 of a wall anchor that will accept a threaded rod for adjusting the angle of the fresnel tray. I will post a picture later of the adjustment mechanism.

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Mirror Mount.

I wanted to have a shelf in the top/back of the box to hold the DVD player and TVBox. It will be about 3 1/2" down from the inside top of the box. This turned out to be a good place to attach the mirror mount. The adjustment is to move the mirror through the centerline of the box to be able to hit the lens correctly. It is not meant to tilt the mirror. It will be at 45 degrees. I may go to a more permanent mount after the box is set up.

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THE BULB!

This part took me the longest to figure out and it may still not be the way it needs to be. I just don't know how much adjustment you need here. I think I hit the centerline of the optics pretty close so adjustability in toward and away from the fresnel to hit the focal point seemed to be what was needed the most. The reflector mount is pretty flimsy so that may also need some work.

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The fans are plastic so the probably need some shade. This is a quickly fashioned heat shield made from a defunct power supply. "Motherhood is the Necessity of Prevention" or something like that. It may not look too shabby after it is painted black.

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This is the first time I have had the box fully assembled, top shelf, back door, etc to see how everything fits. I will take it all apart again to paint the interior with black heat-resistant paint.

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Focus Mechanism.

I am not too happy about how this turned out. The foam makes the inside piece too tight to move inside the outer piece. I may make the outer piece move in and out of the box to focus.

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The focus mechanism assembled and stuck in the front of the box. I need to figure out a method for mounting it so it will be movable.

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LCD

Tried the LCD for fit. I will need to attach it to the masonite after I get a chance to check the alignment.

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LCD Control Module
Here is the controller board mounted using motherboard standoffs (idea stolen from someone else on the forum - thanks).

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Keystone Adjustment

The keystone adjustment is a half-threaded rod that extends through a hole in the top shelf and screws into 1/2 of a wall anchor that is screwed into the screen frame for the top fresnel mount. I plan on hack-sawing the rod to length and attaching a knob.

This pic also shows the control module for the LCD. I considered trying to expose it to the outside of the box, but with a hinged door on the back, I think it will be accessible enough.

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Wiring

I bought some terminal strips but after laying it out, it was easier to wire nut everything together. The wiring requirements were pretty simple in my case. I will have some additional work to do after I decide how fast the fans need to run. The fans will use a wall wart transformer. I have several in various voltages ranging from 4.5v - 12v dc. I would use an attic fan thermostat to control them if I could find one (tried Menards and Lowes, no joy).

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First Light!

Smoke test of the bulb and ballast. It Works!

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Full Burn!

Pic after 15 minutes of warm up. The bulb is so bright it overloaded the camera! Looks like a phaser blast going up. It is full daylight in the room but the brightness shut the iris down in the camera so much it looks dark.

Now I am getting anxious. I am Soooo ready to finish building and start watching!

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I need to find a place to cut the Front Surface Mirror down to size. With that done I will be able to see my first projected image. (lots more to do to finish up though).

Im groovin on this ! Keep it up and lets see some PJ images!
( VERY NICE JOB, BY THE WAY...)

Thanks SamuraiJack. PJ images may come soon if I can get the FS mirror cut tomorrow. BTW, I had occasionally peeked in on your plog but just took the time to read it more fully. A couple of observations. First was your comment about this forum . Likewise! The lack of egotism and rudeness makes this an enjoyable place to hang out. Second, I admire the patience you and Pun15her have shown to redo something until it is right; you with the lightgate and he with the box. I have had to redo some things because I did it wrong the first time but I'm afraid I am too willing to accept "good enough". Oh, and I also made use of your technique for finding the center of a circle with the compass. Thanks!

I am so looking foreward to seeing your results,I think you have adapted that unit so well.It looks like it always wanted to be a PJ!
I also bought some terminal strips,In preparation for a mass of wiring,but really didn't need to use them,keeping it nice and simple,looks like you have thought it all through,your solutions should work very well,liking the keystone adjustment,too.

Loaded Optics Tray

Today I loaded the optics tray with the Lexan, LCD and Fresnels. I took the fresnels outside in the sunlight to see which one had the shortest focal length and installed it in the rear position.

The LCD and Lexan is held in place with double-sided tape and popsicle sticks. "Quality goes in before the name goes on"!


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FS Mirror Mounted!

It was a bit of a struggle to get the FS Mirror cut to size. The second place I took it to thought they could do it, but they had to put in a new cutter and try three times. I was a bit worried that it would be in several pieces instead of just the two I needed. But everything came out alright.

The mirror is mounted on the board with plastic splines. They grip pretty tight but are easily removed.

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(so the extinguished looking gentleman behind the flash is the real arDuck)

FIRST RESULTS!



Well Here You Go, pun15er! Couldn't stand it much longer. The PJ isn't quite complete but is close enough to project. We watched Star Wars: The Clone Wars and watched the temp inside the box. I have a Radio Shack Indoor/Outdoor that I used once inside a computer case I was overclocking. Repurposed it for the PJ temperature monitor. I put the thermometer pickup in the return by the rear fresnel and it stayed below 75 Degrees. I had the fans running on 12V this first time out. I haven't got the box entirely sealed yet so I was worried about the fans not working efficiently.

Two items that need fixing. The image is dark and the focus mechanism is fully extended, which could be related.

Heres Yoda!

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NFS III Hot Pursuit

This is NFS III Hot Pursuit for the game cube. You can tell by the upper right and left corners that I have some obstructions in the image path. The LCD isn't correctly aligned so there is a gap along the bottom of the image. All of these should be easily fixed.

The image is hotspotted in the center and dark on the edges which worries me the most. I will experiment with bulb/reflector placement, swap the fresnels etc. and see what happens.


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On the bright side (no pun intended) the keystone mechanism works just fine although it doesn't look quite right in the pic because of the downward angle of the shot.

Whats Wrong With This Picture?

Here is a shot of the focus mechanism sticking way out in front of the box. If everything is correctly installed (I will recheck my measurements), then the Projection Lens is about 2" further from the LCD than expected. Should be 13.6" looks to be close to 16". There is plenty of room in the box to make adjustments but I am a little dissapointed that it is this far off. I can lower the optics tray and the bulb by at least 1.5 inches if I have to which would bring the Projection Lens back to the front of the box.

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Hmmmm!
Interesting.
I am struggling with this one,as you know,my placement is reasonably similar to yours.And my distances are on the button.The only thing I can think of is fresnels,or distances.Is the distance you mentioned measured from the centre of fres to centre of fs mirror,and out to the triplet?
Sorry I cant be of more help.I presume if the triplet is so extended,the corners of the image are being affected by the internal end of the focus mech tube?
Hopefully its something silly,I put the fresnels in backwards,and the wrong way round twice!!
Good luck.

Just remember, 320mm is focused on infinity. While this works okay for a camera with a lens only a handful of mm in diameter, it won't work for a projector. The whole reason for a focus mechanism is to be able to adjust it.

So 320mm is the ABSOLUTE CLOSEST to the LCD that the projection lens can be with any hope of producing a focused image. And at that, the image would need to be very far away. In order to produce a closer focused image, the triplet needs to be further from the LCD. 12.6" is the 320mm, I set my projector up for a minimum distance of 14" and a maximum of 16.25" -- And it's up against the stops on the travel mechanism at the current setup.

The further that the collector fresnel is from the LCD, the greater the distance will need to be, because the fresnel does have an effect on the lens, though a minor one. Try getting the collector fresnel as close as possible to the LCD (though far enough away to avoid moire pattern in the projection, 10-15mm should suffice.

just a quickie ,what size image are you projecting with the triplet that far extended?
I will take some measurements a bit later and let you know my distances with relation to image size,hopefully this might be helpful.

Yup. I rechecked measurements in the box against my plans and everything is on the money as designed! The "as designed" part may be the issue. See SupraGuy's post.



I haven't exchanged the fresnels yet, but I took the rear one outside again and measured focal lengh. It is as close to 8.6" as I can measure so I am fairly confident that they are in the right orientation. Grooves on both face the LCD.

You know, I read and re-read posts trying to figure out the relationship between the 330/317 fresnel focus length and the 320 projection lens focal length and just didn't get it so this is very helpful. I wish I had understood that when drawing the plans because I was so focused on hitting the measurements on Joe's plans exactly. I would have given it another 1-2 inches for focus if i had.


I have enough adjustabilty in the front fresnel to get it within that range ( 1/2" ) of the LCD. I just lowered it to that position and I could retract the Projection Lens a little. No discernable moire pattern but the brightness didn't improve much though.

My screen size is 72" diagonal so the PJ was 73 - 75 inches from the screen. I have a small room that it is ultimately going in and can't have much bigger screen size, if any.

I did move it closer to the screen and had to extend the Projection Lens further out, and in fact, couldn't move it out far enough to focus. Most of the other builders are going for 100" diagonal or more so I didn't pick up on the difference a smaller screen would have either.

Your PJ measurements would certainly be a benefit in helping me diagnose mine. Thanks.

It looks like the tube that your lens in maybe limiting your FOV and that would affect your brightness and focus.

I think that is (was) the case. I lowered the optics tray 1" and the image brightened up considerably and the focus mechanism is in a more realistic position. I don't think my bulb/rear fresnel are now in spec so I have some adjustment to make there.

Here is how the focus mechanism looks now. Much better.
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Lelu Jumping!

Pic in the daylight of "the" scene from Fifth Element.

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Gotta make some more adjustments to get more brightness but it is looking better. I need to quit for today . . my arms are getting sunburned from fidgeting inside the box with the bulb on.