Some would say the answer to all questions is 42. I say its a Bellhaven. Although, I am leaning towards the IV Bag O' Wine....

Samurai,have you measured a temp outside the lightgate,I was wondering how well the glass stops the heat.I was just wondering that,no matter how well we can cool a lamp in a sealed chamber,how much heat gets to the lcd or fres through the glass.
The only reason i ask is I am thinking that this is the achilles heel on the design that I am thinking about.
Cheers P.

Done a few basic tests, nothing conclusive. I have found some optic quality glass that will block IR. Its a bit expensive, otherwise I would have bought a sheet of that. Im looking at the gate for most of the major heat reduction and then keeping the XL10 to seperate the chambers and block UV.

Thanks Samurai,I may join you in a red iv tonight!

Once I try a few more things, I will try the temp tests at the standard LL length from the arc with a solar thermometer. I have been kicking this one around a bit and I am suspecting I may need to add a very small fan to the slots for the LCD array. Im pursueing a piece of glass that is both IR and UV reflective. If I get one cheap enough I will mail it to you!

If that becomes the case, then the next generation LightGate may have input ports on the front to draw air from the the pre-fresnel area and subsequntly the LCD...maybe...

How was your IV?

Cheers Samurai,actually felt really rough last night!Went to bed at 10:30,without a drop!(unheard of in my household!!!),slept like a baby,and woke up feeling 100%.Guess that means I will just have to drink twice as much tonight!!

I hear you on the secondary cooling circuit.I would love to be able to deal with all the heat satisfactorily within the lightgate,though.
I have alot on at the moment,and not much funds,but I hope to start playing around with a prototype soon.
Cheers P

The heat issue is a big one which could be easily solved if we can find some infrared blocking glass which will with stand a minimum temperature of 400F. Even with turbine winds moving through the unit, we cant stop the transmission of the IR. Since thats the vehicle that heat travels on, thats our target for assasination. I have a call into a friend who is trying to get me in contact with someone who is a glass expert. I also have another call into USHIO.

Im wondering if I can strip out the IR, that the LCD wont need any cooling.

Im hoping to have some time to experiment this weekend, but tonight, Im going to cook a nice dinner, have a few glasses of wine, and relax from the week.

Cheers!

Have a good one Samurai.
I have been scratching the surface(he he) of the glass problem,and I thing what we are looking for is a hot mirror,something like this...Hot Mirror Properties

This stuff looks good.
coated borofloat glass,450 C,>88% light transmission,>98% infrared reflection.
It is only 1.1mm thick!!
Stock hotmirrors
Cheers P

Oh Man! I am surprised we didnt bump into each other at the site! Try this instead:
KG Glass

This is what we need. Its either this or a visible light bandpass filter...

Well, I started a temp test after taking the heat shield off the right side of the heat barrier in the middle and decided to have a cigar ( I have one about 12 times a year...)
...not the big fat ones..just a mild panatella...

So Im sitting there watching the temps go up and slowly enjoying a slightly crispy cigar...and I think about a friend of mine who died on the Lockerby flight in Scotland and I remember something she said about an elusive boyfriend that she had. We were a little drunk and sitting on the steps of a church across from the house where a party was going on...She had finally landed him and she wasnt getting the response she wanted...She said "Sometimes the wind isnt happy when its captured..."
( This was very appropriate because Rick was the male equivalent of an Airhead! He ended up teaching dodge ball to second graders in Long Island...)

and then it hit me!
I was forcing the air to stay in one place!

By forcing the air into the system, I was going against the Tao of the Wind. I was trying to force a situation I wanted instead of letting it happen...I was imprisoning the wind...

I needed to free it!

So I got up, grabbed the power drill and took off the fan and reversed it. Actually I broke the leads and had to replace it with the 110 volt fan from RadShaQ, but its the same thing. Then I watched the the temps drop rapidly down to....

96.2 F! Woohooo! My Lightgate now functions at 10 degrees above ambient!


Thank you Wendy! Thanks very much....


( and I miss you very much...)

Thanks for sharing that with us SJ, sad story with a nice ending.

hi.....

I have a reflector almost exactly like yours, my problem is mouting the reflector.
how did you mount yours, am thinking of drilling a screw hole at center back of
sphere!!
cheers

Check out the beginning of the PLOG. I have photos showing how I mounted the rig with a spare fan screen. You can link it from here... Excellent luck to you my friend!

Sorry, Not meant to be sad, just trying to let everyone in on the thought process. Its all related in one way or another. She affected the PJ. Hopefully, that will make her happy...

I am sure it will make her happy,Samurai.

As far as I can tell,my friend.A hot mirror,will reflect the heat produced back into the lightgate to be removed/cooled.
The shott K glass absorbs the heat,then dissipates it,in all directions,ie:letting some out into the enclosure.The hot mirror is more expensive,but I think it would be more effective????

Knight optics (UK)

Let me know what you think,Samurai.
Thanks,P

PS: I have re designed the prototype lightgate,I will try to make a diagram,but it is proving quite difficult to put down onto paper!!!

For a 63mm x 63mm sheet of that hot mirror is £50!!!!!!!!!!!!!

Thats why I was thinking the other....Eeeek!

BTW, Lego Star Wars.......HUGE TIME SUCK! My kid and I just spent three hours playing it....seemed like half an hour...

Yes,it's such a simple,but involving game.Brilliant stuff!!

Did another temp test last night. Outside of the rig didnt exceed 100F. Still trying to figure out if I want to keep the 110v fan ( kinda loud..) or if I want to stick with the 12v setup. Anybody know what I would need to regulate the speed of a 110v fan?

I just did a quick search and found this circuit. I can't guarantee it's contents accuracy however.

If you wanted automatic control you'd have to include a sensor and circuitry to replace the variable resistor.

I'm going to use this circuit for my cooling, I have 2 120mm 12v fans.

I was thinking of using a positive air flow around the suspended piece of the Shott-K. That way the glass would leech the heat into the air that was coming into the gate. The hot mirror would definitely be more effective and allow for the enclosure to be closed off. If we used the Shott-K we would need, at the least, a tiny intake near the window to draw heated air away from the surface.
I have two 2x2 inch glass lenses coming that are supposed to block IR and UV...one of them has your name on it...

Awesome!!!!
To be on the safe side,I got a quote for a 120mm x 90mm piece of that hot mirror.............£90!!!!!!!
Not really an option then! (gotta laugh)
Samurai,you are a gent and a scholar.

Looks like I might have access to a limited supply...How much do you think post will be. Never sent anything to england...except email!

90 Pounds....Isnt that close to 150 dollars US? Man!

Have a play with it,and if you think it is a valuable commodity,I may pester you for a piece.
Just sat down and watched Gladiator with the missus.It was her first full initiation into the "dark art" of viewing majic images appearing onto walls!!!!!
she said "it was nice".High praise indeed,from probably the greatest sceptic I will ever have.(She did have to put up with the mess of the build after all!).
I am a happy chappy! Acceptance at last into the household.

Somewhere a Chorus of Angels is singing...She has SEEN THE LIGHT!

Now the real fun comes when she can boast to her friends that "my man built this..."...

I feel movie night is about to hit the Punisher Household!

One step at a time,Samurai.
Slowly slowly catchie monkey.(Not that I am insinuating that my wife is a monkey or anything.(Damn,I pray she never sees these posts,man!))

Ha! My wife writes code for a living! I call her "my leetle code monkey!"...

Alright Guys.....
For any of you who are married, seeing someone, or just ever been in love...

This Site is for you all.

Wow!!!At least it makes you realise,there is always someone worse off than you!

The speed control cct listed at the top is described as working on items like drills etc. Electric drills and similar are universal motors. The ac motors used in these fans are induction motors. I do not think that the above cct will work on them.

Chris

Hey,Samurai,check this out.

Surplus shed hot mirror
What do you think????
Is it big enough???
Cheers P

Hmmmmmm.....Im thinking that would be good. I didnt catch if it was tempered or pyrex? Any ideas?

I have mailed them for some specs.Not much detail on their site!!
Might try to get a piece anyway for that price!

Yep, for that price you could use it a a coaster and still feel okay about it!

Ordered 2! By my calculations! 55mm long edge,would put the hot mirror at about 12mm from the lamps glass surround.That is closer than I would like,but looks possible.Should be fun testing this stuff.(still waiting on the specs,if they have any!!!)

Easily done. I suggest housing the glass in metal frame to allow for expansion. Too rigid a mount and it will shatter, as will too rapid cooling

$5 shipping! ,but no info on the specs,they just dont know!(they also only have 2 left now!)

Just a quick update on the fan mods to the Gate.

I wanted a better way to control the heat and tone down the fan and finally came across this little beauty...

Click to view attachment

Kinda nice. This one is from the PCAC fan I bought. Why buy what you already have?

Mounted this inside of the rear board, and Man! It is getting crowded in there!
This was basically my only option. Here's a picture of the way you adjust it. Its adjustable while the fan is on, all you do is swing out the power supply, stick your finger in and twiddle with the knob...you can fill in the rest...

Click to view attachment

I reverted back to a 12vdc fan due to the controller, but in the process, one of my fellow admins busted a 92mm fan from a server, so I took it, extracted it from the cage and repaired the leads...

Excellent! More Air, Less Noise, and speed controllable!

As we single American men say: Remember - no matter how hot the woman is, there's always some guy tired of puttiung up with her s**t !

Sonic! Youre Alive!
How goes the Brain Surgery? did the 520D go in okay?

Yes. But you you have to admit, Mil has a special way of making it all seem so damn funny!

Yes, reading Mil's site did manage to kill a large part of my day yesterday. I was most amused.

Hehe - yep! Mil definately has an interesting point of view; one that we have all shared at some time or another, but never had the guts to put down on paper .

Brain surgery was scheduled, but, at the last minute, postponed due to a remarkable new medication now available - a busted BenQ 557s off ebay for $20. If the medication is effective, no surgery will be necessary...

On the other hand, maybe some brain surgery would allow me a ready excuse for my insanity ... hrrmm

PS: I'm catching up on posts after a long time off - sorry to hear about your little accident; hope all is better now!

No problem. Thanks for the good thoughts. It only hurts when my kids jump on me!, so I figure all is well.

Im holding off on the extraction for mine until the last moment. My shop is too dusty and I will need to make an angled holder for the controller boards due to the shape of the PJ. I think I can get away with a 30 degree angle, maybe even a 20.
Almost have the lightbox done. Still have to finish up the new wires for the upgraded fan and make slightly longer adjuster rods for the horizontal apeture on the Iris. Then I think it will be done. ( yeah baby!)

Just a quick shot of the final back design for the PJ. Under very normal circumstances, I would have built a 1/4 round cover to flow the air around the Electronic ballast. The hole in back for the laser collimator makes an excellent vent! It draws the air around the ballast and its bottom since there is a 1/4 space below the ballast...

Click to view attachment

and because a few of you PM'ed me about the heatsnake...

Its a kludge I put togethe a few years ago. 3 inch dryer pipe mounted to the inside of an 80 MM fan throat...

Click to view attachment

It takes heated air from the computer and brings it over the wall and into the entryway for the house. In the winter, I take it off the wall and wash the air over my dogs favorite sleeping spot...

Click to view attachment

Yes, I love my dog as much as anything...

Oh, and the picture on the wall is me...Riding the most ornery horse in Puerto Villarta...I used to ride, so I figured I could handle him. Not a problem....until my muscles stiffened up a few hours after the ride from not having rode for 7 years!
My wife did the same thing and we ended up limping all over PV for the rest of the week.

What is that funny lookin dark haired animal.The one riding the horse...

Dude! we are fair haired!

Sorry Samurai,couldn't resist!!

Click to view attachment

and because a few of you PM'ed me about the heatsnake...

Its a kludge I put togethe a few years ago. 3 inch dryer pipe mounted to the inside of an 80 MM fan throat...

Click to view attachment

It takes heated air from the computer and brings it over the wall and into the entryway for the house. In the winter, I take it off the wall and wash the air over my dogs favorite sleeping spot...



Awesome progress so far Samurai......

Something to consider: Those older plastic or vinyl dryer vents are notorious for catching fire.

Might want to look into how hot that stuff can get and still be safe.

Just for information...

The plastic dryer vents are indeed notorious for catching fire. They will take the full heat of an electric or gas dryer safely, under normal conditions. They catch fire when they become clogged with lint and debris from the dryer. This slows down the airflow through the vent. The dryer then gets hotter as airflow is reduced. This gets worse and worse until the plastic reaches the point of combustion.

If kept clear, this vent should be safe. Alternately, you can get flexable and extendable metal piping. This tends to hold its shape a bit better, however, flexable piping tends to have considerable resistance to flow, and as such is generally only good to use for short lengths. Proper sheet metal ducting is advisable for ducting of any length whatsoever as a way to keep resistance down. Remember that the more resistance, the more power it will take to get adequate cooling for your projector. I'd recommend 6" sheet metal ducting for a single 120mm fan, 5" for an 80mm fan.

(At one point in my life, I was a sheet metal worker. )

Maybe some of you misunderstood my post, maybe not, but just to set the record straight... The heatsnake is NOT going anywhere near the PJ,nor will the PJ use ANY type of flexible venting system....

Because the heat that comes from my computer never exceeds 110 F, its safe to use this plastic duct and the dust you see in the pipe is total accumulation after two years of 24/7 operation...

dont worry guys,Im playin it safe...

On the other hand..thanks for extending your concerns. I appreciate it!

Looks like today may be a fine day for PJ work...low 80's and a slight breeze!