WORKLOG: Narcoticx2's 720p DIY projector. UPDATED 23-02-08 - Killed my LCD panel!

[seth_jxl]

Originally Posted by Smoke87

Cooling is very ineffective, you are creating a pressure system that will reduce the air intake - you have no out-take fans?

This is true, perhaps a small vent hole some where is in order.

[Narcoticx2]

Update 4: A new design.
Another small update, just so people can get an idea of my plans


Okay, so this is the basic design. As you can see the footprint is significantly smaller yet the projector is significantly taller. It's 71cm tall there (which may seem a bit tall) however that's about the right height i need to make it useable without having to put it atop boxes and textbooks so the image isnt sitting on the floor.

The Airflow design should remove all the hot air that arises from the bulb. Hopefully i will be able to get some heatshield glass so the air rises and sits on that before getting sucked out the exhaust (fans are in a crossflow arrangement btw). Also I will have a reflector below the bulb but i'm a newb at sketchup atm.

Also the section the LCD controller and the ballast are in is separate, hopefully i'll have some ventilation for the ballast fan and to let convection do its bit. Oh and i'll have some sort of covers to stop light leakage out the side fans.

So yeah, this is what i'll be working towards. C&C welcome.

[Narcoticx2]

Originally Posted by Smoke87

Cooling is very ineffective, you are creating a pressure system that will reduce the air intake - you have no out-take fans?

Both of those fans are exhaust fans, and the original plan was to have intake vents between the first fresnel lens and the LCD, thus air flows across the LCD and fresnel lens, down the side, across the bulb and out the case. It works to that effect, however since the case hasn't properly been put together, intake is at the top of the LCD. I've not had issues with heat at the moment however it does get hot and it's something i hope to reduce with the new design.

EDIT: just looking at my new design, i should be able to have some good keystone adjustment ability with it, also, the separate compartment will most likely be high enough to allow the FFC's from the LCD to come across in to it, cause there's a little PCB on the lcd that needs to go somewhere.

[Kliphoth]

just looking at the pic of what your looking at building, as a cabinet maker to me it looks like a peice of piss to build, and looking at your last box..... :P u should really find a cabinet maker friend to help you out :P hehehe

i would be keen to help you out but im down on the gold coast, i build shopfronts all day long so i know alot about little tricky bits when it comes to fittings,

grab me on msn if your keen, but like i said in down in the gold coast, burleigh, so its south end of the coast which is even further :S

blackglass_@Hotmail.com

[Flanman52]

I just read through your log and I'm very impressed. I have a suggestion for the next time you're wiring up prototypes. If your components utilise blade connectors like the mains plug/fuse does - crimp your wiring with spade connectors instead of soldering them up. This gives you more flexibilty in rewiring and changing parts and makes for a more modular prototype. It obviously means a higher risk because you need to insure the connections are secure (leaving the earth off can be problematic ....) but you won't have an issue with this kind of work.

When the Proof of Concept is done the final product can be soldered for reliabilty.

Best of luck with the rest of the project.

subscribed.

David

[$3@N]

What a great project !

The picture of the first box on PS2 Singstar looked amazing.

Cant wait to see this baby do GTA IV !

[Narcoticx2]

Originally Posted by Kliphoth

just looking at the pic of what your looking at building, as a cabinet maker to me it looks like a peice of piss to build, and looking at your last box..... :P u should really find a cabinet maker friend to help you out :P hehehe

i would be keen to help you out but im down on the gold coast, i build shopfronts all day long so i know alot about little tricky bits when it comes to fittings,

grab me on msn if your keen, but like i said in down in the gold coast, burleigh, so its south end of the coast which is even further :S

blackglass_@Hotmail.com

I might just do that when it comes to the case. It's pretty much the first thing we've build, and yes it was pretty simple but when you dont know what you're doing.. well.. you can see the result in this log

Burleigh might not be too far, it'd be a saturday trip though (hour there, hour back is all) so you might hear from me in the future would be great to get some professional help, thanks!

Originally Posted by Flanman52

I just read through your log and I'm very impressed. I have a suggestion for the next time you're wiring up prototypes. If your components utilise blade connectors like the mains plug/fuse does - crimp your wiring with spade connectors instead of soldering them up. This gives you more flexibilty in rewiring and changing parts and makes for a more modular prototype. It obviously means a higher risk because you need to insure the connections are secure (leaving the earth off can be problematic ....) but you won't have an issue with this kind of work.

When the Proof of Concept is done the final product can be soldered for reliabilty.

Best of luck with the rest of the project.

subscribed.

David

I'm pretty sure i know what you're talking about, there were these types of connectors in the overhead projector that i took apart. The just slide on and off. I agree they would allow flexibility, however the switch will only ever be one way (the way it's been soldered) so there's not much point when it's this basic. Some people get really modular and integrate the fans and LCD controller so they are off the one power point.. then it'd be useful!

Originally Posted by $3@N

What a great project !

The picture of the first box on PS2 Singstar looked amazing.

Cant wait to see this baby do GTA IV !

Yeah, i'm just disappointed i can't get more pics at the moment. Basically, i've got no camera (except my DV cam), nor a good spot to put the projector. In my room i get about a 40" screen, and apart from in here there's no big walls in this house Oh, and on top of that, my DV cam doesn't take shots in the dark well so it's pretty much useless for this. The "proof of concept" post was all done with my bro's fiancee's camera, so you can see the difference.

It'd be great to run an X360 or PS3 on it though it has HDMI after all!

[Narcoticx2]

Well, I fixed the last few light leaking issues and balanced out the dim side of the image with some alfoil down one side. Watched an old black and white movie with the fiancee on it last night, as well as put transformers on it.

I actually used a little magnifying lens I harvested from my OHP this time and it increased the image size significantly. With the projector about 3m away, I get a 3m image (used to get around 2m). Awesome.

So, transformers.. well I got the DV cam out to see how it'd go but unfortunately it just doesn't like nighttime without the IR light on... however, i'll put one up just so we can see it IS working.

ps: transformers looked amazing on it. I think I was sitting a little too close though.

edit: since added some more alfoil on the inside. brightness is up but its also directing more heat at the lcd, and i managed to spawn a hot pocket of air on one section which caused the LCD to get a black spot, which got bigger and bigger so i had to shut it down. The LCD is fine, just doesn't work at those temps. Need to get started on the new design asap i think. Also need some heatshield glass desperately!

[Narcoticx2]

Just a small and very unfortunate update. I've killed my LCD panel.

On close inspection, there are a few VERY VERY VERY tiny scratches on those beautiful golden FFC cables. So, it's not displaying what it should. Pretty colours, but nothing useful.. I've got a bit of thinking to do as to whether or not I want to buy another LCD or just abandon the project and pick it up in a few years.

[alvarez]

Maybe I read the problem wrong but wouldn't it be better to spend $10 on new ffc cables rather than replacing the entire LCD?

[Meddish]

Originally Posted by alvarez

Maybe I read the problem wrong but wouldn't it be better to spend $10 on new ffc cables rather than replacing the entire LCD?

i agree....
i think ud proberly be able to take it to ANY tv repair place and say to them here it is i need 2 of these and walk out of the store 10min later $20 lighter in the pocket! rather then buying a whole new LCD!

[Smoke87]

Originally Posted by Meddish

i agree....
i think ud proberly be able to take it to ANY tv repair place and say to them here it is i need 2 of these and walk out of the store 10min later $20 lighter in the pocket! rather then buying a whole new LCD!

No, no and no. NO ONE can replace FFC cables...

[Yoodaa]

Also, before you do anything else, get some heatsheild glass with UV protection....I built one of these years ago from lumenlabs, and if you keep running it without a heat shield, the UV damages the lcd crystals....

You might be thinking "well Ill just run it for a minute till it gets hot", unfortunatly radiation doesnt work that way.

Cheers, and keep up the good work. Dont abandon now or you will never finish!

[Narcoticx2]

Hehe, thanks for the advice, but unfortunately it's not the LVDS (blue/white/black cable from controller to LCD), it's the golden ribbon cables joining the LCD's PCB to the glass. There's thousands of tiny tracks and what's happened is there are a few scratches, aka I haven't been careful enough with it. I was setting it up last night to get some good shots of some movies as I borrowed a camera. Oh well.

I've had some time to think about it and I've decided that I'm not going to abandon the project. My controller board will be sold (can buy 10.6" off ebay but they aren't cheap) and I'll pick up a 12.1" LCD off www.manhattanlcd.com.

However, i've also decided to do a really, really good job on the next case before I even buy the LCD, so there's no risk of damaging the cables etc.

With respect to the heat shield, I've just found pjoz with the help of blenner's log. I'll be ordering some heatshield and a precondenser lens from there. very exciting. May also go with the lower power bulb.

I got a bit shitty last night, I mean it's a lot of money to just blow in an act of carelessness, but then I have to remember that replacing the LCD will still be cheaper than replacing the bulb in a decent commercial projector. So.. I'll still go ahead with it.

So, next step is to get measurements and draw plans.

[alvarez]

Originally Posted by Smoke87

No, no and no. NO ONE can replace FFC cables...

If it has ffc snap connectors on each end then it shouldn't be a problem, But if its soldered to the board like it sounds then it gets a bit more difficult.