The brief:

1. Cheap as is reasonably possible.
2. Portable. I want this projector to be movable and I may want to run it off a generator .

Background:

I'm an an Electrical Engineer. I've got a comercial projector but like to tinker with things . It will be interesting to see how this one compares considering budget is a major constraint.

The story so far:

24-APR-07 Lenses. Standard lens kit ordered from LL, shipped to our Sunnyvale, CA office in the US. Order process takes a little longer than expected and misses first pickup.

16-MAY-07 Lenses. Boss goes through Sunnyvale and forgets to pickup lenses. doh!

07-JUNE-07 Lenses. Another colleague goes through Sunnyvale and finally collects the lenses.

08-JUNE-07 Me. Travel to Europe on business for 6 weeks. Yeesh!

I think I can safely call this a long term project

Ok, now that I've covered the old stuff things have got a lot more interesting....

I searched a long time and missed a lot of opportunities but finally managed to pick up a Benq 547 with a dud backlight on a NZ auction site called trademe:
http://www.trademe.co.nz/Browse/Listing.aspx?id=114192480. $20. Tested it out, yep, it seems that the backlight is the only thing at fault. LCD is partially stripped.

Yesterday I ordered a piece of toughened glass. They said it would take 3 days. I just got a phone call, it's ready, $13 . How are people sizing their glass? I ended up making mine the same size as the LCD when it's still in it's plastic surround. This means it's going to be larger than the lcd by around 10 to 20mm.

I've also been looking into lights. This is a minefield as there are just so many of the things! This is a possibility:

http://www.trademe.co.nz/Browse/Listing.aspx?id=115605106

I'm not so sure that 150w is bright enough but the CRI is 90 and the colour temp is 6500K, which I believe is good.

Still thinking about lamps. After reading and seeing some pics from the guys I'm almost (!) decided on the 150w like they use. It's available in NZ from a local electrical wholesaler (who I've been to.... 3 times already )

Right. About time for some pictures of me stripping....

First, the before shot. It's a Benq FP547.
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After removing all the screws I got out the putty knife and carefully worked my way around the edges. I did a little damage to the casing but since my backlight was dead I wasn't too worried about being able to put it back together.
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Sorry, that carpet is going to turn up in quite a few of these pics

After opeing the casing I saw this:
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I then set about removing all the screws to enable me to remove all the pcbs. After removing the pcbs and the housing I was left with this:
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The panel is manufactured in Korea by LG Philips:
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Removing the surround/cover that holds the LCD to the plastic base/backlight assembly was trickier than I thought. It's only stuck down but you have to work carefully. Fingers crossed that no ffc damage was done. I believe that I was pretty careful with the panel.
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Not careful enough with my fingers though, as while sliding my hand under the metal shield over the LCD interface board I cut my finger. Watch those edges, they're sharp!

Next I started trying to design a system for holding the LCD/Fresnel+Glass/Fresnel combination.

Dad suggested that I use 4 long bolts with a set of nuts holding each piece in place. All I need to do is make frames for each component and allow 4 locations for the holes in each frame.

So far, I have this (shown with my glass still part wrapped. I guess the glass is by far the easiest to clean):
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It uses wallboard joiner from Ulrich Aluminium and some L shaped aluminium from either Mitre-10 or Bunnings. Problem is, I think the taller part of the L is going to get in the way of my image

Back to the drawing board.

Ahh a fellow southern hemisphere'er. I also used a Benq 547 (some very basic phonecamera pics are here http://www.lumenlab.com/forums/index.php?s...4279&st=40) I'm still waiting to move onto building the box etc... I've got some of the wood but am still waiting on my lamp to get a good idea of sizes/distances.

I shall watch your plog to see how you do.

Just so you can see what you might be able to expect another member also used his panel (and completed their box and had a better light source than mine ) http://www.lumenlab.com/forums/index.php?s...%20547&st=0

Just went arond to a place that sells fasteners. They had everything for holding one thing to another.

Here is a picture of the bits I got:
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The rods are 1m long, the pic just shows the end of them. I also got some small machine screws for holding the parts of my frame together that need to be able to come apart again.

Hmmm... I think I might finally have the excuse I need to buy a drill press. Lots of holes to drill, accurately (I can make a rig so that the holes are in the same place in each piece).

This, is why I should keep away from hardware stores...
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Rest of time spent playing with the framing. It's tricky to make all the different sized pieces come together.

And now, the final pieces of the puzzle:
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Hopefully I can really get into the build this weekend.

Time for a quick update on progress from Saturday.

I re-thought my framing ideas again. The channel I bought was way too big and wouldn't hold the fresnels flat enough or the lcd tight enough. I've ended up going for a sandwich of aluminium. Two flat pieces separated by a 3mm flat piece, as you can see in this picture:
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I am using pop rivets to hold everything together that shouldn't come apart (I only had to drill out 3 rivets during the whole day of construction ).

Here are the completed frames:
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From left to right: Collector fresnel, lcd, glass + collimating fresnel.

The one on the far right is using the wallboard joiner channel, the other two are alu sandwiches. The lcd one was particularly tricky since the side of the lcd has some ffcs that stick out about 5-10mm. I used two short sections of the 3mm alu in that case (you can see the extra rivets at the top of the middle one).

Because of the earlier mentioned problem of the ffcs on the side of the lcd I made it's frame join diagonally.
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I hadn't tested the lcd since taking it apart and since it was getting a bit late (and a bit cold in the garage) I had a play. It also helped me determine which was top left front corner (lower left here)
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Another inside job..... After a bit of digging I found the page where I read how to determine which was which.
Looks like my 220mm fresnel is on the right:
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You may notice that my lcd and frenels are not looking very clear and decidedly ripply. That is because I took someone's very good (so far) idea and wrapped that stuff up in glad wrap (cling film). When I'm ready I'll use disposable gloves to handle these.

Lastly, just before I went to bed last night I put on the sunglasses and fired up the light. Geez, that thing is really bright! It was like daytime in my lounge at 1am (I'd just finished watching The All Blacks play Portugal in the rubgy world cup).

I'm going to extend one of the lcd cables, so that I can locate the power board elsewhere. While looking at the board I noticed this area with nothing on it, so I chopped it off with a hacksaw
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NOTE: I did check the tracks on the bottom and none of them went anywhere interesting .

Today I had to do a few other jobs and generally get outside for a bit (it was such a nice day that it would have been silly to spend it all inside the garage!).

I managed to drill the four holes in the corners of the 3 frames. This was tricky, as I had expected and didn't go very well (holes not perfectly in line) but I managed to fix that up. I'm going to mount everything on a scrap piece of MDF so that I can test that everything works before figuring out the intricacies of box building. Here is today's progress:
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I cut a bit of 90x45 timber for mounting the lamp stand but my calculations were wrong, so I'll cut another tomorrow (neighbours probably not keen on circular saws after 11pm ) I've also made an L shaped piece for the triplet that now needs a 70mm hole cut in it.

Last night I did some final test rig assembly.

Things I need to improve (noticed during assembly):

1. The gap between the collector fresnel and the lcd is too tight, so the lcd board can't get around that one very well to connect to the rest of the lcd (hence the glad wrap in the picture). I will raise the frame set up another 50mm and see if that helps.

After some quick mods I was finally ready for the big test.....

It didn't work . These are the reasons I know about.

1. The lamp was too far away.
2. The projection lens was too close.
3. I need to cover the lamp end because that sucker lights up the lounge as if it were daytime.

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Things that might also be wrong.

1. Fresnels - wrong orientation.
2. Fresnels - in wrong place.
3. ???

One of my fresnels has a nasty scratch right in the middle. I was really careful with their handling and wrapped them in glad wrap straight away. There's no way to know when that got there

Fresnels... you already know which one is which.
For all fresnels, in either split or unsplit configurations, the fresnel rings face each other.
If moving the light forward, and the lens forward are both a pain, maybe move the frame assembly back towards the light?

Start with the center of the lamp about 210mm or so from the rear fresnel, and adjust from there.
make sure you can move your triplet (or it's mounting) forward and backward also.

And, build a box that you can put over the lamp, up to about the rear frame, so that you aren't letting all that light out and spoiling your testing! Just make sure the LCD stays cool enough during testing.
The box certainly doesn't need to be pretty for a testing rig.

Good Luck!

Thanks fmerrill.

The first step is going to be hacking up an mdf light box from scrap I have lying around. It will just sit over the back. I'll probably cut a hole and mount my fan on the back too.

I have to move the frame assembly a bit higher (the lcd connection problem) so, while it's apart I could move it along as well. I'll probably check the frenels while it's apart too.

The only thing that is fixed in the picture you can see is the frame assembly in the middle. The lamp and triplet are just sitting there on their mounting blocks (which will have to be re-made taller too).

Looks like you are ready for a test fire come on come on lets see the pics

Looking at the pic of your setup, it looks like the lamp is pretty far away from the lcd, and the triplet is too close (unless you are shooting for a 15' screen). Just a quick observation, I could be retarded. I just finished(sort of) my mechatronics homework. L,R,C circuits...blech , crazy EE's

Edit: Wow, I really should read the whole post so I don't tell you shit you already know. I'm going back to my hole.

Yep :

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Here is the current state of this monster:
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Complete with bits of a shoebox and a pizza box

And here is an image:
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Looks like I really have to make a box now before I can tweak it any more. Problem is that I'd really like to at least figure out the keystone correction first, so that I can locate things accordingly.

How do I determine where my lamp should go?

I found a thread about lamp location

220MM Fresnel positioning, Where's the "g-spot"?

And another:
http://www.lumenlab.com/forums/index.php?s...st&p=123040

Thanks to the tweaking a-z thread.

A mate came around to help with ripping my 2.4m x 1.2m sheet of MDF into sizable chunks so, after cracking open a beer for a job well done I had to do a demo.

Here's an image. Note that there is still glad wrap on my lcd (seen at left and right). The spot on the left looks like dirt. The fresenel scratch isn't visible in this image. Still, even with all that it's not too bad

Miiiiiiilla:
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BTW: I'm using one of these to drive the projector.

Awesome!

(yeah im pretty speechless right now)

Edit: Your building a good projector on a real budget and you have a TVX!?

Good luck, cant wait to see how it comes out!

Oh, and 1 last thing, did you get the venture bulb on trademe, or did you get the ballast and bulb somewhere else? Just wanting to know what the brightness is like with a 150w bulb.

Thanks Swanny,

Mark.

I got the bulb and ballast from Rexel, an electrical wholesaler. The lamp is a 150W Ceramic Powerball MH from Osram with a colour temp of about 4200K.

(goes to look at bank statement and laughs at the large number of "Smiths Mitre 10 ** Nz" entries that appear on it )

The Ballast + Lamp + G12 holder cost me $169.23. The prices at Rexel tend to vary a lot (mainly due to people off the street not having an account and hence pricing structure). Tell them what you're up to and I'm sure they can help you out.

I reckon that the 150w is pretty good and will be fine for dark room watching. My screen is a 4:3 120 inch so once it's complete I'll put some effort in and take some photos.

Ok, a quick report from the weekend.

I did some wiring in the box. Now the LCD and ballast are wired together. To achieve this I desoldered the IEC connector from the LCD's power board and soldered the phase and neutral to the board and used a nut and bolt to hold the earth (will add pictures later).

Now I just need a 12v power supply for the fan and control gear.

I currently have the fan mounted behind the light and it really sucks.... Even with a slot cut in the top my focus mechanism (box in a box) gets sucked backwards by the force of the fan!

I'm not sure what to develop next, speed control for the fan, power focus or should I do some boring stuff like seal up the light leaks

Friend what kind of tint do you have on your image.I mean is it yellowish or greenish or is it natural like the normal lcd monitor.From the pic it appears to have a reddish tint to it.I have a 5300k osram and it is making the colors look unnatural and grrenish.

Hi,

I think that the camera may have put that reddish tint into the image. As I have mentioned (I think) I haven't really sat down with the camera and tuned it to get the colour of the photo the same as in the image.

It's starting to produce pretty good images so after I seal up the light leaks I will try and take some good images.

I am looking forward to seeing lots of pics.Donot forget to post some windows XP desktops like autumn and azul.

Thers no danger of the gladwrap sticking to the LCD is there?

Since youre havin pretty good results with a 150w setup, I think I might get one of these;

TradeMe 150w MH/HPS Ballast

Only $25, (hope its good for our application ) and get one of those Venture light bulbs on there as well, then all I will need are fresnels, and a screen that works. Getting there...

Hope your builds going good!!

Cheers,
Mark.

For $25 it's probably worth the risk, although it does mention something about an ignitor and a capacitor?

I'm not sure that the gladwrap was worth it. It didn't just pull off, I had to half disassemble the lcd holding frame after removing the front fresnel to get it all off. It wasn't stuck to the lcd, more stuck in between the holding frame and the lcd

Im pretty sure its a complete control gear, but for $25 i gotta give it a go!
Hows the progress coming along? Nearly there? Looks like you are, bar a little tweaking.

Off Topic (Sorta):

Hey I was wondering if I could get a favor ??

Theres this screen on trademe, 17" widescreen LCD TV;

http://www.trademe.co.nz/Browse/Listing.aspx?id=119310206

And I really want it!! BUT, its pick up only, I asked the person if theyre willing to ship to Auckland, but no.
I was wondering if you were in that area, and If I won the auction would you be able to pick it up and deliver it for me ??

Just thought Id ask before I even get it, and end up with no way of getting it here.

Cheers,
Mark

Well that screen's been and gone, went for about $100, wouldve been such a good screen to use.

Anyway, where you been? Hows the progress going?
I ended up getting one of those ballasts and the Venture bulb you mentioned, just need a base for the bulb, then Ill test em out.

Hi Mark,

I was in Thames over the weekend and I didn't have access to a computer to pick up this message.

Sorry 'bout that. For future reference anything Christchurch is no problem for me to pick up and send (I can also test them so that we can be sure it's worth paying the postage).

Thats good to know! Thanks.

I see so many things on trademe that are so cheap, and then I check the location and its always Christchurch, buyer must pick up.

Well I always found them up North. Murphy's law I guess.

About time for an update. I've been working away on the projector but not much has changed with the actual box itself.

I'm developing a speed control for the fan:
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The bottom right cable goes to the fan and the cable going into the box is for the thermistor, which is currently taped to the lid of the box. The blue-green-red cable is RS232 going into my laptop (where I can monitor the temperature and manually change the fan speed value). Once the temperature sensor is calibrated the fan speed will adjust automatically. The 12v gel cell is subsituting for my 12v power supply until I get around to sourcing one.

I've been working on a few things, the temperature sensing, fan speed control, keystone correction and servo focus. Lots of things. I have somehow managed to stop myself from disassembling the back where the fan is to fix the not so insignificant amount of light leaking through the fan .

Here is a picture of the servo focus:
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It isn't terribly even at the moment because there is quite a bit of 'give' in the drawer slider mechanisms that I've bought. I may have to use two servos. That won't be fun to align so that they don't fight each other!

Here is a pic from last nights keystone correction testing. The good thing is that this was sitting on the floor - Finally the projector wasn't blocking the view of the screen! There wasn't quite enough correction available here but my camera framing has nicely cropped that out
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I had a flash of inspiration well, a better idea anyway. I'll make a small metal tab so I can move the focus assembly from the middle instead of the side.

How are you keystoning?

Pics look good, making some major progress.

Whats a servo? Is it like a motor?

I'm keystoning by tilting the collector (the one on the triplet side). It's a split fresnel design.

This is an example of a servo:
http://www.acornmodels.co.nz/product.php?prod=9895

They're used in radio controlled cars, planes, boats etc to provide movement to things that need it (eg steering). I'm going to drive the servos with a PIC microcontroller. They're quite simple to drive - you provide a pulse that between 1ms and 2ms to determine servo position.

Here's a picture of up front. Not much has changed - servo now mounted properly and in the centre, power board for lcd firmly attached to side of box.
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Oh, I was meaning like, did you have a "fancy mechanism" for tilting the frezzie

So hows the build coming along? Long time no hear.

Dont know if ive mentioned this but I bought that Venture bulb and ballast, oh and another thing, I manged to score a broken LCD from work (Philips 170B) and I manged to hook the controller up to the LCD I bought off trademe ages ago that needed a new controller, it works sweet, only problem is I cant turn the brightness up too much or the screen will switch off, but thats just a backlight problem Im assuming, and we dont need those. (y) Slowly getting there, I pretty much just need frezzies and building supplies now, oh and a triplet, but I have a OHP triplet, Ill see how that goes before I decide to get a Pro triplet or not.

I've been on holiday in Oz

It's back to reality now though. It does look nice outside though... through the office window

I'm going to use another servo to tilt the fresnel used in the keystone correction.

About time I posted an update!

I installed the front fresnel tilting servo last night (aka keystone correction). I haven't written the software to drive this second one but I'm guessing some kind of round-robin system driving x servos should do the trick (ok, so there is only 2).

Now I also need to think about the UI. I'm trying to avoid using an LCD because I can't be bothered, the cost and the ease of use. Not to mention that it also makes the program larger and therefore takes longer to download...

Three buttons and some LEDs might work. +/-/Mode with leds representing the current mode. Not sure how to do the power up/down sequence though. Maybe I should just use an LCD...

I've had an enquiry about how I earthed my projector. Rather than just reply to them I thought that I would post it here, just in case anyone else was interested.

I'm not sure where you are from so not sure on your local laws. Therefore, the standard disclaimer applies.

1. You should earth anything metal, especially anything that is exposed that you can touch. That way, if something goes wrong it can't end up live.

2. I earthed everything that was originally earthed (which i think was just the power supply board). I attached a small nut and bolt and one of those sort of locking washers (for a better connection) to one of the corners of the board. I also connected the shield from the db15 cable to the signal board (again, like it was originally).

I removed the IEC socket from my power supply board and soldered it onto the board. This was a tidier solution, since it eliminates the join (and the need to butcher an IEC power cable).

I've attached a couple of pictures...

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What a random guy!

Yep, but what have you been doing in the last year or so?.... Built yours yet?

My projector is sadly gathering dust right at the moment. And taking up loads of space!

I'm actually considering disassembling it

Which is a bit of a shame since it's not completely finished (software not written for controlling fresnel tilt/focus/fan speed.)

Maybe I'll take it camping again this year. We really need an entertainment tent

Havent really been very far on the build, well, not the build that I wanted. Ive got everything except for a base for a bulb of mine, once I get that Ill be winning! I bought a PSOne screen off trademe, the box is pretty small, could be smaller though. But Ive been pretty lazy, I have a lot of other projects that I havent finished yet, and I just dont have the time to do them. Plus, I just got a commercial projector, so Im kinda messing around with that at the moment, games are awesome on the big screen! Ive already played Crysis 3 times through, but now that Ive got this projector, Im going through it again. And Race Driver Grid is just too good. I just need a G25, and I think my life will just about be complete.