Well it turned out to be a better day than I expected. The hardware store had just the thing for me today in a couple of categories. Dave is now used to me walking in and sitting down on the floor as I piece together various solutions.

I managed to find a few pieces of PVC pipe which will hold the focus tube and the rack and pinion focuser. To keep too much light from not hitting the triplet, I had to cut down the inner tube. Of course that left the edges really rough....so I designed another unit to help me out...
Meet the Lotek sander bucket...
Click to view attachment

My dad and I used to use something like this all the time in the shop. His was a bit more well designed...ahem..

All this is is a palm sander inside of a Lilo and Stich bucket. I suppose any cartoon character will do. Your milage may vary... It rests near the middle and depends on a slightly off level approach to the piece in question. Once you get it situated inside the bucket, plug it in and adjust it on the newspapers till the peice rotates from the vibration and circular motion of the sander. The bucket keeps it on the sander so you can do more important things like sweep sawdust... It works on round objects too.
Click to view attachment

Easy to do and the results are usually very smooth....

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The top piece is from the original cut, and the bottom is after the sanding process...
..and me fixing a hole in the driveway and having a pepsi, while it was working...

About 20 minutes I would say.
Time to relax for a bit...

Alright, I admit it. I did it.

I went out and bought a hole saw for the beast. I SEVERLY mangled my backplate of the lightgate by forgeting to light my work well and eyeballed it.

Its just pine, but I hate to waste wood.

All I can say is " Wow, Hole saws are expensive...."

I figure it might come in handy since its also the size I use for computer fans and I bought the bimetal one which is supposed to work on metal and wood.
Also managed to cut my lense holder about a half inch too short to work with the pinion gear I have. Good thing it was only 99 cents...

Anyone else find themselves running into a lot of incidental costs?

Ha...I nickle and dime myself everytime I go anywhere now. I think "That might work well with my PJ"

He he,I know what you mean,I have an ever growing pile of "bits and pieces",I have collected over the last few months,that I picked up here there and everywhere.All seemed like a good idea at the time!
Still,they might work on the next one...

I tell myself that a lot, especially with free stuff. As an end result I have a lot of free junk lying around....

Actually, at the end of my build, when tallying build costs, I think the "misc" category was the largest.

Thinks like the Euro style hidden hinges, the cabinet hardware for the focus mechanism, SCREWS! (I should have standardised, buying all those different size screws was spendy!) I spent a lot on "this & that"

Wait until you get the thing up and running... my HTPC and Satellite costs are quickly dwarfing the PJ costs... Oh well, the wife still has nothing but good things to say !

Good news and bad news....

I will start witht he bad news. I seriously underesimated the length of the focus bar on my rack and pinion assembly and will have to make a new lensholder....

I knew I was having too much fun saturday...
EDIT: Wow that picture is really dark. Basically the one with the rail on it is 3 inches long. I cut the lens holder a bit too short. I can mount the rail on the white piece if I dont cut it down.
Click to view attachment

And now the good news....!

Finally came up with the scheme I needed to vent the lightgate and implemented it tonight. bear in mind, the lightgate is seriously BETA...
Since the box is small and componentized it needs to breath ( Like fine Champanga...'The Continental')..and breath well. This scheme takes advantage of passive heat exchange and the tendancy for heat to rise. My original scheme had no fans in in and was passively based. I think it can still be done, just not now.

Here is a photo of the gate with its innards exposed

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and another angle so you can see the vents

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The vents are rather passive, but you get the picture. The gate will vent out the back with a standard computer fan. I tried a 110 volt fan, but it was noisy and moved less air than the 12 volt. In the words of Malcom Reynolds: "huh.."

The lightgate takes air from the top of the box over the blades/fins of the ventings.
This little doohickey ensures the air thats going out only comes from the top of the box...Lots of hard bending in that one. Dont mind the blood..

Click to view attachment

Once thats attached you get this:

Click to view attachment

I couldnt resist. I HAD to know. Would it work?
( What would Brian Boitanno do?)

Looks nice, temps are rising steadily...

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and the result is....

This is my hand on the lightgate directly above the bulb, the area I guestimated would be hottest...

The gate has been running for ten minutes, maybe longer. Its warm but not uncomfortabley warm.

Click to view attachment

These are my basic results of the first test.

Factors:
1. Box is not sealed and is still white all over the inside.
2. Temp probe was placed in standard postion at 3/4 on mogul side of box.


Results.
1. standing temp and ambient tempt is 64.9 F
1 min = 65.0
2 min = 65.2
5 min = 74.1
10 min = 85.6
15 min = 99.1
20 min = 102.3

Light shut off: 102.3

30 seconds later: 100.1
60 seconds later 97.5
90 seconds later 89.2

I know its not all that impressive, but I think Im onto something here...Well not really. People have enclosed lamps before. Im just jazzed with the progress and the mad scientist fun!

Gonna go have a beer!, or maybe a really cold Cream Soda...

Anyone else find themselves running into a lot of incidental costs?

[/quote]

I have about three oak trees worth of 5/8 inch stock pieces with grooves routed in them, some partially painted black, some not ....all cut to about 3-4mm shy of where they were "supposed" to get cut!!!! And as someone else said, wait until you are "done!!" I also laid out to upgrade computer, theater room, etc. But the thing is just so darn cool you can't help it!!

[quote=Mr.Blutarski,May 24 2005, 07:49 PM]
Anyone else find themselves running into a lot of incidental costs?

[/quote]

I have about three oak trees worth of 5/8 inch stock pieces with grooves routed in them, some partially painted black, some not ....all cut to about 3-4mm shy of where they were "supposed" to get cut!!!! And as someone else said, wait until you are "done!!" I also laid out to upgrade computer, theater room, etc. But the thing is just so darn cool you can't help it!!

[/quote]


Hehehheeee. Yeah It IS a lot of fun! Gonna paint some parts black tonight to see how it goes!

OMG - do I just!! The LCD sled had to be redesigned and re-built 3x. The triplet mount, 2x. Fiddly little harware parts: nuts, bolts - drawer slide here, thermostat there - it all adds up

First I had a budget of $200 - overhead projector and panel off ebay.

Then it went up to $500 - might as well build the lumenlab project and outsource the parts.

Ah, screw it, ballast, lighting, lenses and fresnels are such a pain to match. Up the budget to $600 and go to the LL store. Ooh the e-ballast looks nice ... $650.

MDF is cheap, but heavy. Hey - wouldn't it be cool to STAIN the box! 4x8 sheet of birch ply is only $50 ... Budget up to $700.

Wait, you mean that most people use BenQ's becuase they have good specs? Boy, those pictures sure look nice ... What's that you say? They are being discontinued?! I can pick one up for HOW much??!! Deal, $250! Budget up to $750

Wouldn't it be cool to build a fan speed control? After all, I got the wall wart for free ... Oh crap, it overheats, I'm going to need heatsinks and a dedicated fan for the circuit, $20.

Wait a minute! You mean the eballast has to be actively cooled outside the box or it will fail?? Another $10.

Price to date: $780

The experience: priceless

Time for a redesign and a paint job!

Basically I was looking at a lot of light loss from the back and of course the whole box was either white or putty colored...

So I removed the lower casings and modified the air paths so they were less "in the open" and also directed them to the front of the box. I used some simple channels and some bent aluminum.


Click to view attachment

With this done, I changed the back and allowed more room for the vents, then painted it all with some low gloss stove paint...

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This is a picture of the bulb before I place the rear cover on..

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Seems to be looking better. Im hoping this will block a lot of light...

So I made up a quick shield to contain the light. I can switch these any time I want. I had designed a really complicated focus thingy, but I think it might be over kill.
The shield is the gold piece. The back is flat black...


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This is the unit fired up against the door of my garage/den/shop of doom...

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The temps I read from this session were a little better, but Im still concerend about the hotspot above the bulb..

1 min 59.3 F
2 min 62.1
3 min 64.7
5 min 77.1
10 min 81.8
15 min 86.7
20 min 89.0
25 min 91.7
30 min 92.3
40 min 92.6

However the hotspot on the top of the box is another story...

Click to view attachment

Yep. you are reading that right. Its very hot in that spot and good that is not...

161.4 F too warm for my tastes...

So I think I may rework the vent system to add one of the 4.5 inch radial fans. I started the box with those in mind ( thats the wide channels at the bottom...)
but wandered over into minimalist cooling. I think I need to vent more...

Feel free to chime in with any suggestions you have, I am open to other things as well.

Pun15her,
Dude, Im sorry I missed this post somehow. Sorry I didnt mean to look like I blew it ( or you ) off.

Yeah the lightgate is working but I have a hotspot issue I need to fix. Im thinking about a baffle and some fiberglass.
The clean circuit is the best shot, I say. I learned the hard way that sometimes things dont go quite right and downed a server we were working on when I plugged in a machine I was working on.
(The screams were awful....)

Jurassic kitty is pretty good. He seems to have gained some more weight since the mice have come out.
...the neighbors dog hasnt been seen in a few days though...

Hehehe. Broke down and ordered two fans from the LL store. Now I have to wait patiently. Not my strong suit....

I've been fairly quiet in this PLOG... But I wanted to chime in and say that I like the engineering, the idea is good, and the execution looks even better.

Patience pays off, by Pun15her's example. I fully expect that your results will be excellent, given the attention to detail that you're showing.

I agree from the looks of it. Your skills look very good. keep it up

SupraGuy
I am honored. Thank you!

I started this one so I could give everyone a good long look at the process. When I first joined I was a tiny bit miffed that there were so few pictures of the build process. There were a lot of Heres my start...Im finished plogs. Mostly just people racing to get a shot of their PJ's on duty. Im hoping that someone will be able to read this one day and get a firmer stance on what they want to do. Maybe even inspire a little confidence...

...plus... This is SOOOOOO much fun!

( Its like your first chemistry set all over again!)

I did intend to take a lot of nice detailed construction shots, but somehow at the point where the tricky stuff got started, I just ended up bolting stuff together, not much interesting to take a picture of. My mogul base is literally just screwed to the side of the enclosure, no fancy adjustment at all, then I placed the sled in relation to that. By the time I was DOING the stuff I'd prepared for, there wasn't much of interest to take pictures of.

I think thats what happened to a lot of people. I caught myself thinking the other night, that if I put in a really good push and I had the LCD, I could finish in a few hours.

Im trying to take my time, but there is this little kid in me going "C'MON C'MON!"

Hey Samurai,

Great work so far in your PLOG - I look forward to the new posts every time I log on .

Got a question for you; have to play Devil's Advocate doncha know ...

Why are you concerned about the hotspot temperature at the top of the lightgate? This area is directly above the arc, so it seems logical that it would hotspot in that area. Also, isn't the bulb designed to run optimally at high temperatures; It seems that overcooling the light chamber might actually be detrimental ... The main point of the lightgate is to concentrate the heat of the bulb to the chamber and then vent it out, isn't it? My gut feeling is that you might be overly concerned with the hotspot temperature.

Just wondering about your thoughts on the matter; Devil out

Out out! Ye Devils!

Thanks for the compliment

Actually, you are right on some ( probably most ) of this. I do want to keep the bulb nice and toasty. The problem will lie with my children and that hot spot. I dont want anybody getting burned, and 165 degrees will do it. I plan to do a three hour test soon and I have a feeling that spot will only get hotter.
I also plan to enclose that case in the wood frame you usually see it on. Its designed to slip in and give me an inch of play for fine adjustment from the rear fresnel. The inserts I will use for the squares will probably be some pretty nice wood, so Im thinking that retained heat due to enclosure might come to flamable temps.

Picture the following scenario:
Kids are off to bed and the wife and I sit down for a nice movie. We have a glass of wine, then promptly pass out due to sheer exhaustion from watching the kids. The movies plays on, stops and the PJ sits and cooks...
Im looking to avoid filling in the next part

Im looking for a safe box.
( Plus my kids look so much better without bandages...)


Thanks for the feedback, though. Im thinking that there is a thin fireproof material out there that also has insulative properties. 1 sheet of this on the top of the box and Im good to go!

It doesn't need to be all that fancy. A thin layer of fibreglass insulation will work well for keeping the "no-touch" zone insulated, and safe. Of course I don't know where your lightgate box will be in the final scheme of things. I had assumed that it would be inside a larger box. My children have already been taught to stay away from lightbulbs, (Well, except the baby, who can't react the projector at all, even if he were in the basement where it's kept.)

Alternately, fins bonded to the metal where the hot spot is will dissipate heat faster, possibly bringing it down to a non-burn temperature, and might even look cool. That would take some experimentation. A fan running over fins would keep the outside cool while allowing the inside bulb temperature to remain cool. Event he exhaust fromt he fan that's keeping the LCD cool would provide a lot of assistance there.

Where the baby is kept?
I like the heatsink idea.how bout a zalman sealed to the outside,samurai?Promising idea!

Actually the whole point of the lightgate was to keep me from having to do active cooling to the LCD. Although with the monitor I am eyeing it might be a good thing. The design I have in mind ( subject to change at any moment...) calls for the ability to seperate the lightgate from the LCD array. Same with the focal module. Im planning on using a piece of XL10 to block the UV before the rear fresnel. I already ran the heatsink route. I thought it made the design less "elegant". Plus it limited the motion I want in the lightgate and would make basic maintainence a chore. More to come on that a little later...

I still cant shake the passive cooling system I designed. I think it might work.
It s one of those things I will just have to put to metal and see...

Thanks for the feedback. My kids have been taught the "lightbulb/hot hot/stove" routine too. They are very smart, but you can never tell when the child instinct will rear its head. Cassie is only two and she has a young and innocent soul. Her sister, on the other hand is 7 going on 35.
Mostly, Im really more worried about long term heat build up and easily flamable wood.
You will see why when I post some pictires of my living room.

That is...if I can ever get a front end loader in here to clean out the toys...

EDIT: ( Have you ever noticed that you dont see spelling mistakes until AFTER you post? )

So the wife is out of town....( hehehhehe...)

Can I party? No. Can I work on the PJ? no. Can I at least conceptualize? Maybe.

Spent a little time working on the focal module. I had about 20 minutes..

I cut the last piece too much so this one I just left at its standard length.

Click to view attachment

A side shot of the rack and pinion gearing I will use for the focuser. I got this from a friend who got it from a german microscope that the university was trashing. A very fortuituous find...

Click to view attachment

Lightgate is on hold for now. I think I might get my fans tomorrow. Im hoping anyway. If not, maybe Saturday.

I think I may also have a simple solution for the hotspot.

SupraMan, you were defintely in the ballpark whern you suggested heatsinks. If I get it done tomorrow, I will post my idea.

Alright Babies in the Basement sounds like a Shel Silverstein poem....

You have a basement?...sigh...Our basement is an apartment that pays 92.1% of our mortgage.

Trade offs, Trade offs Trade offs....

I'm thinking that the 92.1% of the mortgage is a little more important than a dedicated projector room. (insert non-existant smiley-face of smile face rubbing cash together in hand)

Well...Maybe, but still: A Place to keep the baby?

Just joshin on you all!

Yes! I always find my mistakes right after I click "add reply" (though it probably doesn't help that I do the bulk of my posting late at night). I used to be able to spell too, but I think over the past several years I've become spellcheck dependent (darn MS Word).

I'm very impressed with your lightgate design and all the thought you're putting into it. My cooling system design went something like this:

(jig saw in hand)
"I have 3 vent covers... I think I'll cut holes ...hmmm.... here, here, and here."

...luckily for me I made good guesses when I cut vent/fan holes & haven't had to make any changes. However, if I make a second PJ, I'll definitely take some cues from your design. What you've got are some great (and very original) ideas, and I can't wait to see how it all turns out

That was the missing variable I wasn't taking into consideration - the kiddies! I can certainly understand your concern.

As for the lightgate getting hot enough to burn the wood - if purely passive, that is a possibility. It would probably reach equilibrium long before the ( 600 degrees F?) temperature wood flashes at, but better to be safe. Have you considered adding a high temperature shutdown to the projector so that it will turn the lamp off in case of overtemp?? I am putting one on for that reason precisely

BTW: I LOVE that rack and pinion assembly you have for the triplet; your pj certainly is cutting some new ground for innovation! Can I ask where you purchasedthe rack and pinion assembly; was it pricey? It looks like it might be a viable option for my pj as well ...

Since the pine Im using for the prototype is a pitch/resin based wood, I would lower the temp consideration even further. I think I have a good idea for a baffle plate inside the lamp space. Im just waiting for the fans.

The rack and pinion was a gift from a friend of mine. He was going to use it to build a telescope mount. He salvaged it from a german made microscope, but I would be willing to bet you could find the basic assembly in an automotive shop?, or a astronomy store, Maybe? The whole focal assembly for my 8 inch telescope is only 36 dollars new.

Or...

Just go to ebay and look for focuser in the search. Here is one I found for 99 cents. Focuser

Savage the parts and adapt your own.
( yes, its spelled correctly...)

Ahhhhhh....
I had the most luscious surprise on my doorstep when I went to pick up the kids:
My fans! Thanks Brain! Gotta love LumenLabs ' response time! I had found the fans for cheaper on the net, but I believe in paying a little extra for good service.
If I decide to go with a poly UV filter, Guess who's getting my order?

So I decided to quickly hook one up and test it and was immediately inspired by the new possibilities this fans offers.

I can t wait to start monkeying around with it.!

Lumenlabs claims its first victims...

I havent actually been able to get into the garage long enogh to do anything, but my mother in law is certainly willing to watch the kids if Im gardening.

So Im out whacking weeds of the side of the garage, thinking about the inside of the lightgate and I wipe out half my daylilies before I even realize it....

Just a funny aside I thought I would share. This process is SOOOOOO addictive!

Been in the garden all day today.Kinda theraputic!
Makes a change at least,gives you a chance to take a step back and re-assess your product!
Now get back in that garage and give us all a progress report!!

Oh, I hear that!

I've been giving a fair amount of thought to your setup as well, as well as other ideas. I may be transplanting my projector's guts into a new case this summer, dependant on me getting the time to build one (And of course that I don't spend that time turning my brains to mush watching movies!)

Your lightgate will certainly have a role to play in the revised projector, I can hardly wait to see what other tidbits you come up with that I can adapt.

Now, get back to work!

Ok,Samurai.
I think I saw you good self posting with some degree of dvd playback expertise,not so long ago?
I am hoping that my dvd player is going to arrive some time this week.
In preparation,I have been using zoom player,and have today installed fdd show,and the sonic cine player decoders.
Seeing as I have absolutely no knowledge at all with this stuff,I was hoping you might be able to tell me if this should be a good setup???????
(sorry if this is a little off topic!)

Okay. first of all. what did you get for a player and what machine will you be running it off.? More than happy to help.

Okay...

first I must confess to you all that my secret addiction has raised its ugly head yet again. Its hard to work and its even worse knowing that a single lapse in judgement could bring about the total destruction of all you hold dear....sigh.

Civilization III has to be the most adictive game I have ever had and I got a chance to play again a few days ago. You would think I would have learned by now....Just one more turn...Yeah I need to find a good spot to stop...

But I finally made it into the garage after the wife came home from her CON...

The basic problem was the hot spot on top of the Lightgate. I had thought up a whole slew of ideas to deal with it, but finally went back to the simplest solution I could find.
This is the original model for the top vent....

Click to view attachment

As you can see it has no top shield. So I took a piece of full density fiberboard and cut it to the same dimensions as the bottom of the top vent, covered it with tin flashing and screwed some extra heat sinks to the metal side...

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and of coarse, I painted it black.....( Thanks Mom,)

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The high density fiberboard should have an ignite temp of 475 degrees and the metal flashing and heat sinks should draw away about 1/3 of that so I am thinking that the outside of the gate will temp out at about 110 F. Zalmans for the next one...

Ooooooo Heat sinks? Jack, how did you do that?
(yes, Im being sarcastic to myself...)

Simple.....They are bookstand racks. 2.99 for 8 feet of them!. Cut with a metal saw and attach with self tapping screws.. The greater mass of the metal with the combined airflow SHOULD keep the heat from migrating to the other side as much as it normally would.

Heres a quick pic of the heatsink with the mounted vent...

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And then the whole thing painted black to cover any flaws....

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Didnt get a chance to fire her up, but I think this will work. If it doesnt then I can use a bit of wonderboard or even a small piece of hearthstone shield for the sink. But I think this satisfies the DIY requirement of not breaking the bank and still doing the job.

I have to work out a new spacing problem with the fan, but I think this mod will turn out okay...

( In case I didnt mention it before, I really love doing this for you guys. I know its mostly my interests Im serving, but its really great to be able to contribute something... hope someone gets a little something from this...)

Cheers!

excellent stuff Samurai!
Very nice work!Looks to me like you could be onto a winner there!
I can tell that alot of thought and effort is going into this pj,and I am looking foreward to the end product.

(I am running win2000,with an athlon xp2500+,and 512mb.
And a shuttle mn31n motherboard,which has onboard Geforce4 mx gpu,and nForce2 igp host controller!(hope that makes sence to you!! )
I hope to build a dedicated htpc,or maybe adapt this one,and build myself a new gen purpose pc!
Oh yeah I am waiting for this beast to arrive:USB2 dvd on ebay
I appreciate your help,cheers)

Oh yeah, it all makes sense. Its like being out with my geeky friends. This is one of the 333 FSB ones right? Tops out at either a 2600, or 2800?. It should be good to go for your setup. And it did have a good number of USB ports on it if I remember right. I would pop another 512 in there. The only problem I have read with external USB drives is the power being supplied through the port. Sometimes they dont get enough through and it can result in flaky behavior, expecially when ripping to the local disk. For playback, they are generally fine. GeForce MX4, thats a two head right? That will help so you can compare monitor versus PJ. Let me see what else I can dig up.

Thanks for the encouragement!

Yes on all counts!!
Another 512 coming right up!
Cheers for the help,Samurai,much appreciated.
Very handy,having 1xmonitor and 1x pj hanging off it at the moment!!

I will look for the best setup tutorial I found when I was playing with it. When I find it, I will post the link. You did get the pro version of the player, right? Bear in mind this thing will suck CPU like nobody's business....

You are a legend!
Is this the type of thing that you are planning?
Yeah got the pro,with the fddshow osd turned on,it is showing about 50% cpu useage,upscaling some aweful 352 x 240 res video upto 1024x768.
But with a little choppiness,not much,but enough,(on the monitor,that is,havn't tried it running on the pj yet!)
Cheers again,Samurai
BTW: I keep going back to the pic of the finished heatsink combo,it really does look very nice!

Thanks! Okay I found the spot where I began the hunt. Go Here...

This is pretty straightforward. I actually wasnt planning on doing this just yet. Im concentrating on the optics side of things first. I think I may have found a way to improve the triplet.

Im concerned about the heat build up but Im hoping the heat sinks will offset it. I am also hopeful that the "non-space" ( read : no air pockets) above the flashing will minimize the chance of a flare. I also figured out why my projected square didnt sit right. It added a half inch to the scheme and the new fan will also effect it. So its off to recreate the air duct!

Awesome,Samurai,looks like a pretty useful site,cheers.
Now,how the blooming hell are you going to improve the triplet????
Well,If anyone can...