Hey SJ.

Sorry if it seemed like a criticism, it wasn't intended that way. My intent was simply to give additional information to anyone who would build sich a rig for their projector. The concept is workable, but would need different materials. There seemed to be questions about its usability for a projector, so I figured I would address that. Like I said it was a "just for information" thing. (And you'd still get better flow through using rigid sheet metal piping. )

Oh , No offense taken at all! I was just clarifying in case someone mixed the two up. I could imagine someone working a heat snake off the PJ and doing it wrong. Keeping it in their cellar and suddenly finding their closet on fire because of dust or lint...

Not on my watch...
Gotta keep it safe and sane...

Supraman, you still rock!
( and you strike me as my kinda guy; a dabbler in all things and a constant addict to the drug of newfound abilities and knowledge...)

Ready for the last little bits of the Gate? You may want to wait more then....

So I assembled the gate and buttoned up the USHIO....

This is the Bulb before its alignment...

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and this is after a quick alignment...

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I also did a few other things in preparation for test. It really is nearing its release stage for version 1.0. Im happy with it so far. I do need to make a few minor adjustments which I will show in the next few posts. Most of these have to do with keeping that stray light under controll...

The Iris on the Gate doesnt have to be very big and I have a feeling I oversized it by a factor of two...In shaving off the light from the sides, I had to extend the sides so much that light is bleeding through the back edges. Easily fixed...I will just have to make new side slats. Later on I would find out that the combination of the wide arc and the Iris come closer to being a square than a rectangle because of the arcs width. Im hoping I can engineer this down to a smaller square..then I can add another trump card to the pot! That card is for all of us, by the way!

A picture of the longer screws...

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and ..the end result! This is with no adjustment...

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This is a picture with about 5 minutes of adjusting done. The fun part is now I get to see where the flaws in the physics are...

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You can see how the light is fairly well contained inside the area of the frame. There is a serious dropoff, but there is still stray light. A little poking and sticking my fingers here and there ahnd I have come to some basic conclusions:

1. The complete sphere reflector, while in theory is good, does not do well for this because it creates more stray light than a 1/4 sphere or 1/8 sphere. Light reflected off the lip of the reflector just goes up towards the top of the box etc.. Cutting down a spherical reflector and adding more light absorbing surfaces would yield better contrast for most designs. With this in mind, I will most likely shave down my reflector. This is why the ladle works so well. it s a smaller section of a larger radius sphere.

2. I can either make the Iris smaller, or I can make the adjuster plates larger to cut back stray light from behind the panels.

3. I would love a circular arc chamber!

Hope you all are enjoying this as much as I am...

I will probably make a few minor modifications to the gate and call it Gen1. Done.

Oh and since some of you know that I love ideas that come from unexpected places, I leave you with this...

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Hi Samurai, Your lightbox is looking good. Any temperature tests yet?

I'm hoping to have enough of my lightbox together this weekend to do my testing. The reflector I'm using is a soup ladle - very close to the bulb. Theoretically (ie in a drawing) it's big enough to reflect the required arc. I'll probably make a fixed gate, and then just cut the hole bigger until i get to the point where it's acceptable.



I'll try to post last weekend's progress in my PLOG tonight. Been too busy with work this week...

My temp tests have been great. I have the bulb inside of a 7x7 x14 gate enclosure with relatively quiet venting ( 27DB at full go, quieter ay down speeds). The highest external temp I have recorded was 110 F. The inside is nice and toasty. My last temp probe inside the box yielded 170-190 F. I think the bulb burns better at a higher temperature.

Right now Im working on a cheaper filter for IR. some of those babies are expensive! Dont get me wrong, I love designing and playing around, but we need to be able to actually buy the stuff. A 200 dollar IR filter might be cool, but it isnt really practical for most...

Nice design for your rig in the PLOG. I have been dropping by....

So what does Samuraijack do when the day is over?
Does he relax and contemplate the nature of being? Does he write haiku next to the Koi pond? or does he rest comforatably knowing that he need avail himself of no technology?...

Nope. He goes home and plays with his new IR filters!

I managed to get ahold of two IR filters on the cheap and may have a line on more. The were made to filter heat out of a slide projector ( HINT HINT...)
and seem small, but I figured my apeture to need 1.5x2 for a dimension. This happens to fit it.

So this....


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becomes this....

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Which happens to fit well over the gate apeture. For me to use the whole cone I will have bring the filter in a little.
I opted for the most serious and objective of science tests...I put my hand in front of the gate, then placed the filter, put my hand back in etc...
It works very well. there was a seriously noticable reduction in perceived heat against my palm whenever the filter was in. I think its safe to say I will be mounting this in the next few days within 2 inches of the Arc.

Then, just for the fun of it, I played a little with the edges of the iris and came up with these results...

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I found a way to reduce the ambient and leak light from the shallow blades I used on the Iris...Drape a piece a aluminum flashing over it. Im currently thinking that I want to make the blades bigger, or install flyers on each side. I will most likely remove the inside glass and place the filter instead, counting on the air coming across the filter from the front to cool it...

HOWEVER......I am getting "antsy" about finishing...

Samurai,the world will be a worse place once you finish,not for you,but for the rest of us,waiting for the next step.I love the side rails,they are just beautiful.But all the work you are doing controlling the light is medal-worthy work.May you never finish,and keep us entertained for the next 20 years.(Sod the family! )

That's a pretty solid 'light square' on the wall. Looks like you've nailed it Is the 'dimmer' area on the outside just reflection off the wall, back to the lightbox and then back to the wall or is it coming from inside the lightgate?

Ah Dude, your makin me blush...

Hope you all are enjoying this as much as I am!

ozstang65,
As near as I can tell, those odd dim zones are coming from inside the Gate. Im thinking about putting a couple of flyers on the frame so I can control that too. I THINK they are the result of my relector having too much material in the front, but I havent gotten a chance to examine it closley. If I can Im going to try to tune tomorrow night. I still have a lot of playing to do with the box.

Man oh man, you are engineering the heck out of this thing! Something tells me you enjoy the process more than the destnation Your results will surely be awe-inspiring. Can't wait to see projections! Sometime before my 40th birthday please (you've got another few years)

OK the heat is reduced. But the big question is, is the light reduced?
a. at all?
b. some?
c. a lot?

Most IR stuff seems to reduce light as well but haven't seem numbers on them, I'd be interested in hearing your results.

Most of the numbers that I've seen indicate that IR blockers are about 90% transmissive to visible light, which makes it about equivalent to 2 panes of very clear glass. So yes, it will reduce light, but only by a couple of percentage points.

I just had a thought.... Due to the eye scorching brightness of our bulbs it is very difficult to tell exactly what is causing any light spillage. I was wondering if anyone had ever used an arc-welding shield to try and look at the light?? I don't have one to try at the moment but I can get hold of one eventually.

This seems about right. Maybe a little on the conservative side. Im going to dig out a light meter I had for a german SLR and take a few readings.

Engineering the hell out of it?
Nah, Im just challenging myself to do the best I can...and it just so happened that the project I was working on when I designed this model had multiple 20 minute wait periods, during which I sketched and let my mind wander around a bit.

I am a firm believer that any one of us can do it, and do it well. If you had the curiosity to pay the 19.00, then you have what it takes.

SupraMan, This IR coated glass seems to be a little less intrusive than the window material I was working with. I think some light meter readings will help.

SJ

Just as a question... The IR coated glass will take care of IR, obviously, but what about UV, are you planning on also using XL10 or a UV barrier of some sort before the fresnels? Given the damage that excessive UV can cause, I'd think that this is somewhat important.

The lower ambient temps from the lightgate are impressive at the very least, you ought to have a very quiet finished product.

Good question. Right now my light path is ARC-Tempered Glass ( from a Halogen lamp).

I think in the end it will be ARC-IR FILTER-XL10.
The XL10 I am planning to mount just before the rear fresnel.

The low ambient temps are good, but the end result is still the same. No matter how good the cooling is, you are still adding a quantifiable amount of calories into a static pool. IE you are still adding heat into the room. Basically, I am just venting it faster than some of the larger style boxes. As my rig comes more closely together, you will see that it is a combination of aesthetics and safety that drove the venting of the box. I have ideas for the next one that will be more efficient and probably quieter.

The finished project is fairly quiet now, but the fan I chose to use ( a server vent fan from Dell, AKA NIB) has an odd little metallic rasp to it. I might replace it with a cheaper quieter version. The modularity I made with the speed controller lets me replace the fan in a little less than a minute. I find I can turn down the fan a lot and still have good temps, so I could use a quieter, slower fan. Once I remove the tempered glass, It should be even easier to move the air.

Right now Im just trying to have fun with it.
My wife says Im "totally geeking out" with the project.
But Im really enjoying the build and I hope someday to make an easily made, reproduceable design available to anybody who wants to do it. Thats why Im trying to come up with ways to do things cheaper.

I want whatever comes out of this to be available to everybody

Well, its recovery day here at the House of Flying Innuendo...

Friday Evening my wife calmly walks in to my office and asks if "im ready for tomrrow?"
Hmmmmmm. I think to myself Has she finally figured out that a day of unadulterated lounging around sex might not be a bad thing?

"Remember sweetie?" she says with that cute smile, "Were taking the kids to Great Escape ( Thats a theme park the next state over from where I live...)

"Oh...Yeah Babe, Im good to go"...

So my plans for Friday evening and playing with things got waylaid and of course Saturday eve was completely out of the question...

But I did find something I thought was pretty damn funny...
There's this girl riding on the Carousel, with this tattoo on her neck. I thought neat, took a picture and then decided to ask her which booth she got it in...
"I got it down the street" she says "Its permanent!" She was all thrilled about it.

I hope she wears her hair down when she gets married...

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Pun15her has minions everywhere....

Just looking back on your lightgate projections I noticed the 'lightsquare' is a bit bulged along the edges. When I fired mine up thisevening I held the 220 fresnel up in front and got the same result. Is everyone seeing this effect or is it a reflector thing?? (might have to remove my reflector and try it sometime)

Nice,I have been thinking about getting one of those for the last few years,but I never seems to reach the top of the list of things to do,It never gets above number 3 or 4!!
Awesome work on the light gate,Samurai.
Cheers P

Actually, my fresnels havent even come out of the bag yet, Im still playing with the gate

my bad, i should have gone to bed earlier.....

What? A red-headed chick with a tattoo on the back of the neck?

Thanks! Im going to try to put some flyers on it tonight and see if I can mount the IR/UV lens. Im a little concerned at how close my calculations say the filter will be...1-2 CM from the outer glass of the bulb. Trying to figure out how I can move it around without going blind

Well Crap! I tell you if I wasnt less of a cultured person, I would be sitting in the driveway in the pouring rain thinking about ways to do the PJ in...

As it was I calmy ran through my vocabulary of epithets, curses, hexes and assorted nasty phrases that are pretty much gauranteed to make even the most seasoned of courtesans blush...

It was a design flaw and I knew about it it, I just forgot...
I even mentioned it a few pages ago...

Let me take you to the beginning of the evening...

It was agreat evening to be working on the PJ because it was raining like no end. This meant no little visitors...

I had been playing with an idea for the past few days about double Iris and its effects on the PJ. I was thinking I could get a pretty sharp line that way so I made a few quickie, cheapie "flyers", which is what we used to call them in theater. sometimes we called them flaps as well.

So here they are...

Secondary light blockers to catch stray light from the secondary fields of the arc, thus making the contrast better...

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So I place them quicly and start bending them around and having fun. Soon I come up with this pattern...


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Its starting to look much better and I AM getting clearer demarcations between light and dark areas....COOL! I am almost elated...

So on a whim, I find the center of the PJ piece and mark it for target. Then I removed the Plexiglass I will use as a target and template and trace it onto the paper, then crosshatch and reticle the target for ease of comparison...

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So I pull the target back to see if it scales evenly...It does seem to scale well. Pretty much even around the target...Now Im starting to get happy! Cheap and easy and the group can reproduce it easily for about 2.50 (US)!

Naturally, I got greedy...

More to come....



EDIT: The dark shadows you see in quadrants 3 and 6 are the screws that adjust the iris shutters. They will be trimmed later...

and greedy is the word....

I noticed that my corners were a tiny bit dim as you can see from above. So I decided to adjust the reflector to see how it effected the light pattern, which in hindsight was looking pretty good anyway...( yes, I am an idiot...)

So I got out the screwdriver and went to work, tweaking this way and that and then suddenly all went out of whack. Nothing was adjusting and I was getting nervous. So I opened the side up to look at it and damned if the reflector had not broken off and was lying on the bottom of the gate.......arraughghghghgh!!!!!!

(I was on a roll! I was this close to something elusive...maybe

"Dont make me angry, Mr McGee, You wouldnt like me when I'm angry...")
(anyone? )

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The victim and the culprit. Remember when I said in my basic conclusions that I would like a smaller reflector? Well the...

"projector's reflector caught
in the grate of the gate
and the whole thing got stressed
and then totally messed..."

Thank you Dr Suess!

So I think I will take this failure to heart and trim the reflector down to the ratio of the 4x3 mirror reflection based on a theoretical cone spread and then block the light internally...

I did, after all, say I was going to go for a smaller reflector...

Two steps forward and one step backwards is still one step closer to nirvana....

It's looking good, Hopefully i'll be enclosing my lightbox this weekend, i might have to pinch a few of your ideas

Be my guest! Pinch away! Im going to be cutting down my reflector during lunch. Im taking an inch off the sides which should leave it at about an inch deep. Should help to keep some of those weird bounces out of the way.

So here I am in the cube farm at work....Lunch is a fast five minutes and I figure I have about 10 minutes to spare. So I start snipping down my reflector. Little sounds of "Pink" here and there.
Next thing one of my fellow 'mins walks in and asks what I holding. I tell him it's the inside of an ice cream dish.
He smiles and goes "Man, you must really hate ice cream!"

I love the geeky life!

So I cut down and polished out the edges of the reflector. This is a picture of the little sphere in its original size followed by one of it after being cut down...

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and a very liberal coating of JBWeld to seal the deal...

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Had to stop work on the gate due to a storm coming in...Looks like its gonna be a fun night!

So riddle me this folks.....

What does this...

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Plus this...

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divided attention by an episode of Mythbusters and one VERY sore arm come out to?


This...


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Does this reflector make me look fat?

No but that big gut of yours does! LOL J/K


That's a nice job you did polishing the reflector!!!!

"Soooooo, You dont find me attractive anymore?"

any male in a relationship should feel the warning bells go off...NOW!

Well that implies I at one time found you attractive!


NOT!! LOL



Seriously, nice job on the reflector!

Hmmm.....Let me guess...SINGLE!

( Possibly Lucky bastard@!)

Nope, married with a pregnant wife!

VERY happily married I might add, you aren't going to tempt
me away! LOL

Now get back to polishing that reflector!

Where did you get the "Never Dull"???

Local hardware store. Really old product. My grandmother used to use it. My hardware store is part of the "Do it Best" chain, but I know Aubuchon sells it too.

Well, I opened the shop door and it was literally a bazillion degrees in there...Ah who cares?...Time to play!


Two more polishing sessions since the last picture and the reflector is looking pretty nice, so I need to move forward on mounting the IR/UV filter. Problem is the glass is only 2x2 inches, so I have to mount it inside the box. I figure that while I am at it, I might as well limit the ambient light some more and begin the basis for PJLG2. Double Irides!

So I like to recycle, mostly because I freakin cheap, and because if I screw it up, it was really just a piece of junk to begin with. Some of you might recall in chapter three, subsection 19, paragraph 5, that I took apart a power supply from an old 486. So I found the cover and used that as a base...

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Cut the sides off and you have a rigid frame made of soft japanese pig steel, easy pickins compared to some types of metal...

I cut down the top ( sorry for the poor metalwork..) and adjusted the offset to compensate for the variance inside the gate. Canting the center view upwards by 3/4 of an inch. Then used a sharpie to mark the "nest" for the glass filter...

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Out come those bloody nippers again. I swear they are the best thing my wife ever gave me as an "Oops I forgot your birthday/Impulse buy" type present. I think she gave them to me because she didnt know what else to get me. If you do case modding or metal work of any kind, these are great to have.
Go slow and dont overstress your hands...

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Finish it off with a flat broad metal file and there you go....

Wondering why those rubber bands are around the glass?

I should make you wait, but Im not that kind of guy!

Rubber bands? On a lens/filter? Yep! Since this filter is coated, it it going to be extra difficult to clean. You can t just "rub it off" without damaging the finish. So if you are going to be handling it a lot, wrap it in a few rubber bands. The bands are tight enought that you can still get good tolerance for the fit, but most important, they stop your from DIRECTLY TOUCHING the coatings. They also provide minimal protection from scratches etc if you need to put the down on a flat surface.

Still concerned about the coating? You should be. They can be a delicate. Go to a local optometrist or camera store and pick up a "lens Pen" It allows you to clean 99% of coatings without harming them...

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Yes. The filter is in there. Its just optically nuetral and I happened to hit it at the right angle...

Here is a much closer shot after I have drilled the holes I will/might use to hold it in...

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...and the final product after a quick painting...

You see the shape of the wire. I originally though I could just connect the corners with wire, but my tolerance was too big. Since I am going for more 16x9 I can afford the wires across the bottom and top 2 mm. Once the paint dries, I will mount it and the secure it in the lightgate at 1 -2 inches from the arc center...

Wish me luck, If it works, we all have cheap heat filters, if not, well its been fun experimenting...

Cheers All! I hope you all have a good night!

So after a day full of whining customers, I retire to the shop...
The peace...
The smell of wood and finishes...

THE B-52'S! Yeah!

Did I get a lot done? No. but I finished the filter holder. I was going to use a complicated wire strand technique, then I thought "Well, Hell...Who is gonna want to do that?". So I opted for this instead:

Basically just two strips of flashing, cut small on each side of the upper and lower portions of the inner iris..No big deal, easy to do. Costs all of 25 cents...

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After they are in flare them with a screwdriver so they can hold the thicker filter. I figure I lose 2mm on each up and down side, but Im after 16x9, so Im not worried...

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And then test the seating of the filter...I like the red glow off the filter face, thats the IR blocking component....Uhmmmm....

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Now a quick spray of high temp paint and it will be ready to install tomorrow AM...

Well, after a weekend in which all motivation to do ANYTHING was gone, I finally got back out to the garage...

I actually took a nap with my 2 year old this weekend...By the way, naps are very cool...

So back to the project...

I painted the filter holder and mounted the 3mm thick filter on Saturday AM...

Like so...

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And then mounted it inside the gate about 3CM away from the arc, not touching like in this picture, the filter stand stood up straight when I torqued it down...

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Then I installed the reflector, cut down and polished as well as I could...

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Looks pretty nice, I think,and NO it doesnt make me look fat...just bald! Hahahahaaaaa!

And this is the final result of the cutdown and install...

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Did I fire her up? Well of course I did and the space in front of the PJ was noticeably cooler than before! Yeah Baby! Cheap filters for all!

But! I did run into a problem which I want to sit on for a day so I can think my way through it...But I will post a picture of it...

As promised, a picture of the new mystery...

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Somewhere I am picking up these odd little reflections and I cant figure out where, but Im coming up with an idea...

Just a guess, but maybe it's reflection (refraction??) from the 'bottom' or 'top' surface of the IR filter or its holder.

I'm loving that light 'square', it's got great definition.

Excellent progress Samurai!
That light square is very impressive!!
I am glad your filter is holding up.
It gives me hope for my hot mirror.(which I have been too scared to touch after the first one got roasted in in my oven!).
Cheers P

Thanks for the compliments guys!

OzStang, I think you have it on the money. I willing to bet that the light is coming off the edge of the filter plate. Tonight Im going to look at using an old astronomy trick to fix that. I think I may also have to spray the inside of the trough. I also need to blacken the flyers so I can be certain they arent adding to the problem.

I wish I could find some stiff hinges instead of bending them...

Pun15her, it was too bad about that filter, but I think someone said you would get different results in practical use. You might want to try a base piece of glass with clear finish on it to experiment with. The finish will discolor and distort if it gets too hot. Once you get the cooling right, then you could substitute the filter!

Im thinking it might be time to whip up a batch of "Uruk Hai" salsa and seek divine inspiration!

Boss, you might try one half of a small set of "fully-mortised" door hinge; that way only one hinge is required to hold the IR piece, and it can be tensioned with whatever it uses(star hex/torx-head, ect.) Just a thought.

Oh, sorry for the confusion. I was refering to the Flyers on the outside of the gate. These on this page...
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Although, If I could find some hinges that had tensioners on them, it would be pretty much the same. Thanks KitaruSapien! Good idea!

Well, I ran through a very primative exercise with MSpaint and I think I can say that the odd reflections are coming from the edges of the filter itself. I was able to guestimate it with this drawing:

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I think darkening and flashing will take care of it. Only problem is I have to take the gate apart... again.

Hmmmmm....Okay so I got a few PM's asking what Uruk Hai Salsa was...

Just a quick one...

Christmas last year I made some very good salsa. We name each batch after something on TV. Lord of the Rings was on.

This is the label I used for the batch!

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In case you couldnt tell, Im working from home today...and Im "motivationally challenged"...Been at this SOP since 6:30AM...Time to go to the garage after I pick up the kids...