Well, I’ve packed it all up now. This project is officially on hold until the next time I come back.

However, when I first entered the room yesterday with the intention of packing it up, I decided to give it one last shot. Working for a day to put the parts together as best as I can, I ended up having built a makeshift fortress-that-is-falling-apart-kinda-projector. Here are a couple of shots. Yes, those are a pair of black tshirts.. I needed something to stop the reflection around the LCD/fresnel sled.
 

I had worked on this for quite a bit, I wasn’t just going to pack it all up. So I put together the little mess you see above, connected my computer, held my breath, and flipped the switch. The light flickered on, and slowly got brighter. I watched the projection on the wall with hope that it will continue to get brighter until I got a nice LCD projection going. Alas, it was not meant to be, for the final resulting projection brightness/quality is way below what I was expecting. I took some shots, but they are not worth showing.

Here are some possible reasons for my failed attempt.

1. Plenty of light leaks. Though I tried covering up as much as I could, I couldn’t stop all the light from leaking.
2. Poor alignment and placement. I pretty much eyeballed everything, so the triplet, LCD/fresnel sled and lightbox all probably had their axes way off from each other’s.
3. Poor design of lightbox. I didn’t even plan my lightbox.. just stuck the lamp in the box and kept cutting the hole as I guessed would help improve the quality. Initially I kept getting one small bright rectangle of light in the center of the projection, so I cut the hole bigger to let more light out. This did work, but it reached a point where cutting the hole bigger didn’t increase the size of this “bright rectangle”. I think this is where I screwed the lightbox over, as the overall brightness started decreasing.

Yes, I did get the lightbox done. Well some kind of lightbox, anyway. As I just mentioned, it’s probably junked by now, and I’ll have to make a new one the next time I work on this. Here are some pictures:

Yeah.. I made it out of a biscuit container and an empty can of oats. I think my Mom was happy to know that she was able to supply me with something, although she had no idea I would be mutilating it like that. I also plopped a heatsink from an old processor on top. There’s actually a fan on top of it, but since I don’t have a DC adaptor lying around and I have no need for the crazy cooling at the moment, I took the fan off. Note: I needed to add on the extra can because the original container was a tad bit short.

Well, that’s it. Tomorrow being National Day, my relatives are coming over, so I had to clear out the room. Since I won’t be having much more time after tomorrow, I decided to just pack it up for good.

Ok then, it’s been a fun project.. can’t wait to be able to finish it up in a year’s time.

I’m not too sure what’s up with the lighting. Maybe using flash wasn’t such a good idea.

So far here’s the list of materials I’ve used:

• Metal Rails from IKEA “HYLLIS” Shelf (Hardware shops were selling for $1.50 a foot.. this one was way cheaper. Plus I got some shelves to play around with.)
• Nuts and Bolts from nearby hardware shop

I’ve also already cut the remaining lengths of rails that I intend to use. I’ll be uploading my current design idea in the next post (this one is just a quick update).

I have been working on this for almost 3 whole days (not nights, though, I’m a good neighbour and don’t intend to wake up the neighbourhood with my drilling). I’d love to keep going at this rate, but unfortunately I have a test coming up that I have to study for, so this will be done only now and then, during study breaks or something. You know how priorities are.

Here’s what I have left to do (in the order I plan to do them):

1. Attach triplet lens
2. run tests to figure out proper position of lenses and light source
3. build and attach lightbox
4. work out cooling circuit
5. attach fans and put frame into case
6. take care of wiring

Hm, quite a bit more to go… I’ll give it this week until Saturday. If by then I still have a long way to go, and depending on my studying progress, I may have to put this on hold until I come back again next summer.

Here’s a sneak peak at what I’ve been doing, I’ll write more about it in one of the next upcoming entries.

Anyway, here’s a quick update. So far I’ve done a few ray tracing diagrams, which didn’t do much good (I found out what I already know), found the focal length of the OHP fresnel, and worked in the triplet to finish off the setup.

- Finding the Focal Length of the OHP Fresnel

Basic setup to experimentally find the focal length of the lens, as learnt in secondary school. Put an object on one side of the lens, put a surface on the other side, move surface until object image is focused on surface. Measure distance between object and lens and distance between image and lens, use equation 1/f = 1/o + 1/i .

Bottom line: found my focal length to be ~120mm (best estimate based on 4 trials).

- Working in the Triplet (finding appropriate distances between lenses and stuff)

Image on the left shows the setup I threw together, and image on the right shows my lamp all covered up to simulate a point source light.

I got the required distances with some help from the lumenlab forums (as usual) and by using their focal calculator.

3am, tired. Will finalize design details tomorrow.

Here are some shots I took while stripping the LCD, sorry I’m not going to walk you through it as I really was just figuring it out as I went along, and by now I have forgotten what I did. If you need help stripping an LCD, there are many good walkthroughs on the Lumenlab Forums.

I forgot to take a shot of the panel alone, may do so later on, so the last shot is the closest shot to seeing the panel alone.

Excuse the interesting mattress, I wanted a soft surface to work on to avoid any hard hits to the panel while I was stripping it and that was the only one available. Also excuse the poor photo skills, I don’t take much photographs and I just wanted to get on with stripping the LCD.

Pictures will be coming later, but for now, here is a shot I took after plopping the panel onto the OHP just to test if it’s still alive. (Sorry for large filesize, but it’s 4am and I need to be up by 9.30 tomorr- er, later. I’ll fix this later.) (Now uploaded two new shots, reduced filesize)

I’m surprised at how good the quality actually is. The fact that it’s just simply put on the OHP and that the OHP bulb is only a 250w halogen. The photo doesn’t do full justice: my – well, my brother’s – digital camera quite frankly, sucks (for example, shutter speed not fast enough, causing blurry projection this time I’m awake enough to pause the video before taking the photo).

Firefox has a cool feature – tabs. Middle-click a link to open it in a new tab, ctrl+T to open a new tab. The Tab Mix Plus extension makes tabs a whole lot more fun. For example opening in a new tab links that open in a new window, and the Session Manager.

During one of my research sessions for this DIY LCD Project my Firefox froze up and I had to force end it. Upon opening Firefox again, Session Manager came up asking if I should restore my last session: 6 Windows, 60 Tabs.

(note: 60 Tabs is the total number of tabs open in all windows)

• Osram Powerstar HQI-BT 400W/D [$40] + E40 Holder [$12] [both from Sinter Electrical Company Pte. Ltd., #03-05 Sim Lim Tower]
• Parmar HPS 400W Ballast [$28] + Capacitor (30 microF) [$10] + Ignitor [$16] [all from Sinter, same as above]
• 3 meter ‘power cable’ (I don’t know exactly what it’s called.. it’s the cable you connect to the wall) [$3 - Sinter]
• One OHP (triplet lens, fresnel doublet lens, glass) [$20 - Asia Asset Recovery , through eBay Auction]
• One second hand 15″ Fujitsu LCD Monitor (model unknown) [$150 - Weng Cheong Computers, #04-02 Sim Lim Sq.]
• 2 meters of ‘electric wire’ (heh, again I don’t really know what it’s called) [$3], One Switch [$2] and One Terminal Block [$3] [all from Space Centre,#B1-41 Sim Lim Tower]

Total Damage Done: $292.30 (After GST)

By the way, you should have noticed that I managed to get a second hand 15″ LCD. Yes, by chance I happened to find it when searching for the 7-8″ screens. Looks like the shop found it in the dumpster, though, as they knew nuts about it. However, I got them to hook it up and it looked decent, so I went for it.

The 7-8″ screens, which can be found quite commonly at Sim Lim Tower, were some “Super LCD TV/Monitor” models, and they didn’t look that great. Shopkeepers also knew nuts about it, one tried to tell me the 8″ model had 800×600 resolution, but another shop leaked that it had only 640×480 (or somewhere thereabout). Furthermore, the screen didn’t do too well on a DVD test. Looked decent for TV, but not DVD. Either that, or the shops used pirated DVDs. Well serves them right. Anyway, the cheapest I found was $165 for 8″, $155 for 7″, so the unknown second hand Fujitsu looked like a better buy.

I hope to start tearing things apart after a dinner provided by the Mom. It’s been a tiring day, but I wish to get this done by the start of next week.

With $150, I figured I could get a first hand small panel LCD that I saw over at Sim Lim Square / Tower. Will be going down tomorrow to check them out again.

As for now, it’s time to start looking into the small panel option.

In other news, I am considering changing my choice of bulb from the Philips HPI-T to the Osram HQI-BT or HQI-TS. The output Lumens are about the same, but it has a better color temperature. Will have to check what the price is on these, though.

Now that I’ve gotten everything accounted for and confirmed that it should fall within my budget, real work shall begin into making this a reality. Design plans and final grocery list shall be coming soon.