____________________________________________________________________
A note for new readers...

This is a lengthy PLOG. I purposely did it this way to give everyone the feel of
the process and its effects on basic life. It has lots of pictures and I try to explain
what Im doing along the way. Im hoping that some folks will get some good ideas
from reading this and maybe a better understanding of how the process CAN go.
There's some humor and I make a few good mistakes. There are some rants and a
few serious issues. It's a basic look at life and a PJ.

This is a project worth doing. The satisfaction is tremendous and the fun is outrageous.
Individual results may vary...

I hope you enjoy it as much as I am.

SamuraiJack
8/12/2005
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Index..


Chapter 1. The Component Theme

Component Boxes begin
The Lightgate Begins
More work on the bulb and bulb base
Work on the Lightgate resumes
Modding for Less heat / The rear design
The insides of the Lightgate
Ready...Aim...Fire! Collimation and Aiming
The LCD sled begins
First Design Concept revealed: The "Anti-Box"
Harlequin Romance meets LumenLab: The Story of Stephen and Sophie...
Basic fresnel frames and the origin of "The Rails"

Chapter 2. More Fun with electricity and wood...

Wiring the Lightgate Temp controls etc...
IRIS construction
Still working on lowering the temps and then a breakthrough...
Fine Tuning the LightGate
More work on the LCD sled
The "Enzyte" method of triplet mounting
More Mods to the sled
The 3D Fresnel Adjuster 1.0
The 3D Fresnel Adjuster 2.0 - Simpler, Easier
My first Projected Image - with no eclosure!
The LCD Panel gets stripped - A Tech Noir Romance

Chapter Three: Form, Function, and the Wife Approval Factor

more to come


START ORIGINAL LOG:

Okay, with finances finally set properly and my car running like a japanese kitten, its time to start the PLOG...

Sorry no pictures yet, ( CORRECTION: Pictures below ) Im still settling on a design scheme. Basically I want to make a unit that has the following qualities:

1. It needs to be pleasing to the wife.
2. I need to be able to break it down.
3. I think Digital inputs are probably going to be needed.

I have ordered the standard 15 inch lens kit and bulb/Electronic ballast from LL.
Backordered, but I remain hopeful!

The original design called for a folded 15 suspended from the ceiling, but the wife put the nix on that one when she saw how far it had to hang down. Now I have returned to the standard plan, but will modify to meet my needs. A folder of paper about 3/4 of an inch thick is my sketchbook and planner. Its filled with sketches and ideas that I developed along the way. I think the starting point for me will be the lightbox.

Wish me well!

Before I embark on this project, I would just like to thank everyone for all their help and the great community that seems to thrive here. I have been on the net since before it was open to the public and its a rare thing to find a decent set of people being civil and helpful to each other. You all deserve a big hand!

I was playing with some other ideas for a ceiling mounted projector. The excessive keystone from having a projector overhead is one. I think I have a solution.... The FOV of the lens seems plenty adequate for a larger LCD, which also means that it can see the lens from further away. I'm considering rebuilding my 15" project for ceiling mount kind of like the folowing diagram. This may even be able to use an unsplit fresnel configuration, with no keystone correction required. The idea is that by sloping the light path in the projector, it can be mounted higher, hopefully high enough that you can walk underneath it without banging your head.

This may (or may not) take care of point #1. (The only way that I could take care of point #1 is to not have it.)

For point #2, how break downable does it need to be? Like to be able to flat-pack ship it around? Could be tricky...

As to point #3, that's all going to depend on your LCD monitor that you choose.

I think Im probably going with the CMV-520D. seems that folks have had good luck with it.

Basically I need to be able to place it in my trunk and possibly bring it on an airplane. Most of the reason is for modularity and conserving resources. I have already designed the lightbox to be self contained and adjustable. Should be very easy to service too. If my rudimentary drawings are right, it should be about 7x14 and about 6 inches deep. The eballast looks like its going on the outside. I have also designed a spring loaded LCD sled which should do okay. I aslo managed to get my hands on a rack and pinion gear for a larger telescope for the focuser.

Should be posting some pics of the reflector tonight. Since Im using the LL lamp, I am going with a 4.5 inch reflector.

Samurai,it's about time!!!
Glad to see you are jumping in.I wish you the very best of luck.
I think it sounds like a pretty interesting design,portable,airplane friendly,spring loaded,modular,AND pleasing to the wife!!!!!
You will need all the luck you can get!!!

I think if I unbalance the fan, I can make it vibrate too!

Got a bud in the warehouse digging cardboard for me right now. Gotta love a prototype. Now if I can just get past my angst of compairing with designs like yours...

The folded PJ was supposed to hang in between the beams of my house. They are 48 inches apart. I had originally thought them to be 16 inch beams, but I found out after I measured them that they were 12 inchers. The original placement called for the PJ to hinge on the bottom section of one of the beams, and fold into the space between the beams when not in use. I used a 15 inch width for the mock up and that MIGHT have been okay. But I drew the line at the box hanging below the beam when it was folded up.
Since the ceiling is tounge and groove over the beams, there is no slack space I could use. I will see if I can get a picture of the frame on the ceiling so you can get a better idea.
It might have been okay, but it gave the room the feeling like I should put two handles on it and use it for scoping out the nearest enemy vessal.

My best guess is that it would have been fine for folks sitting on the couch, but standing or moving around would have been awkward. It was about 2 feet tall, so heaven help you if you have a 7 foor ceiling.

Anything I can do to help is yours for the asking. I have a gravity controlled keystone mechanism for verticles that might help you.

Samurai

EDIT: Duh. I just read the post again. The basis for my ceiling design was joe2000chevy's projector. Its a sturdy tested unit. You can find a set of plans here:Joe2000chevy's Vertical design.

Many thanks, Joe!

do you have pictures or drawing of it? like to take a look at it.

Thanks, Joe

I shall try to describe it. My drawings are more impressionist than anything else.
Basically what I did was to take a lightweight frame to house the lens. You can use glass if you want to stiffen it up. The key to the vertical keystone is the way the weights are attached. I took two pieces of thin wire and fastened them to each corner of the frame. This is assuming the fresnel frame is using a centerline pivot. Psuedo mount the frame so you can work with it and then balance the frame with a level. Once the frame is level, you attach two static weights to the bottom of the wires. Once the frame is mounted in the PJ , gravity will effect the two weights and keep the frame level.

Rudimentary Paint drawing I whipped up for you. :
Click to view attachment

Just a few pictures of the reflector in the process.

Basically, its an Ice cream Bowl that I picked up at the local KOHLs. It was a little expensive ( 9.00) but the bottom was smooth and its very shiny. I seperated the inner and outer layers by grinding the top 3mm of the lip off and breaking the weld. Very easy. Just go slow so you dont overheat the metal. The inside and outside pieces seperated:

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It LOOKS to be part of sphere:

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Needs a little shining on the inside.

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Next is doing the geometry to find the exact center of the sphere...

Had to go back into the deep recesses of my mind where I store really old facts to come up with the lazy way to find the exact center of the sphere and plot my cutouts from there. I have never seen this posted so I thought I would do it. My apologies if this is redundant.

Heres how to plot your points for exact cutouts in your reflector.

First, take your finished half sphere or reflector and trace a circle around it.

Click to view attachment

After you do this, get a drawing compass and eyeball where you think is the halfway point. Place the needle on this point and stretch the copass draw point over to the far side of the circle AND A LITTLE BIT MORE. When you draw the arc, one spot will touch the outside of the circle. That will be the point where you place the needle to draw an opposing arc

Click to view attachment

See how the arcs intersect above and below the circle? Draw a straight line to connect each of those points. If you have done this right, it should cut the circle exactly in half. Put the sphere back on the paper and mark the places where the bisect line emerges from under the sphere. Viola! Exact halves.

Now since I am planning on using the LL bulb, I used a circle that was exactly the width of the bulb plus two mm. I might have to make it slightly bigger. Fold the circle into 1/4's. use the circle folded in half and use the 1/4 crease to line up the marks on the sphere.. Mark your cutout area and you should have a perfectly centered pair of cutouts for your bulb....In theory anyway.

Ready for cutting out...

Click to view attachment

One thing I found out was that the ceramic base I bought was far from perfect. After screwing the bulb in all the way the it was not perfectly perpendicular to the side of the box in the x/y plane. So my nocthed reflector had to be altered a bit to accomidate this.

Good point. I hadnt thought about variations in the mogul base. I think I might make a duplicate of the reflector assembly to match the socket so it can all be adjusted. On the other hand, I do have a secondary mirror holder for a newtonian I might be able to use.

Does anyone know if the LL bulbs are machine formed or hand blown? It might make a big difference.

Samurai,
I,m not sure about the glass itself,but I can tell you that the metal threaded base of the bulb is not square to the glass,(at least on mine!)
When screwing in the bulb to the mogul,the other end of the bulb rotates in a circle of about 20 mm diameter!!!
So keep that bulb mount adjustible,each time I have,screwed in the bulb,I have had to re-position the entire holding mechanism,in both axis!!

I also had this problem, but I choose to level the bulb by shimming the mogul base as nessessary to get the arc chamber exactly where it was supposed to be. Taking the bulb in and out after the mogul base is aligned is ok because the bulb screws back into the same position every time. If I change bulbs, I will probably have to adjust the shims accordingly.

http://www.lumenlab.com/forums/index.php?s...indpost&p=66133

I like the level. Have you had to change bulbs yet? I was wondering how big the variations are in each bulb.

I guess I'll be able to provide something of an answer to that when I get my replacement bulb... Tried sourcing one locally, no dice, so it looks like I get to wait for hte LL store to ship me out a new one.

Thats right, you got your bulb finished off by "Destructo-Kitty", didnt you?

I also have one of those, a 28 pound all black cat named "Q". He's so big, he cant fit through the pet door and when he jumps down off the dryer, the floor shakes. Im working on the new mount right now. Im supposed to be working, but no one else is either. I guess they all think today is long lunch day...

Nah, I cant do it, I have to go back to work....

[/quote]

I like the level. Have you had to change bulbs yet? I was wondering how big the variations are in each bulb.

[/quote]


Haven't changed bulbs yet (only about 30 hours on mine), however, I did roll the bulb on a flat surface to see if it was the bulb or mogul that was off. The bulb appeared to be concentric about the threads on the bottom. The mogul itself seems to be problem. These are not precision parts and I believe that the way the way that the socket fits into the ceramic base is to blame for the bulb being cock-eyed in relation to the mogul.

oh yea; if you use a level to align the bulb, be sure that your box is level BEFORE you align the bulb... I had to do it over after I realized what I had done

[quote=GadgetSmith,Apr 29 2005, 06:39 PM]

[/quote]

I like the level. Have you had to change bulbs yet? I was wondering how big the variations are in each bulb.

[/quote]


Haven't changed bulbs yet (only about 30 hours on mine), however, I did roll the bulb on a flat surface to see if it was the bulb or mogul that was off. The bulb appeared to be concentric about the threads on the bottom. The mogul itself seems to be problem. These are not precision parts and I believe that the way the way that the socket fits into the ceramic base is to blame for the bulb being cock-eyed in relation to the mogul.

oh yea; if you use a level to align the bulb, be sure that your box is level BEFORE you align the bulb... I had to do it over after I realized what I had done

[/quote]

Good Tip! Thanks for mentioning that. I can very easily picture myself doing the same thing. Im pretty certain I would have if you hadnt mentioned it. Grinding tonight. Unless the natives ( ages 7 and 2 ) are too restless.

SamuraiJack

Now for the fun part...Cutting out the insets for the bulb. I was concerned about a few things. The first was scratching up the interior, and the second was bending the shere out of round. I think I found a way around it. Originally I was going to grind the whole section, but I had a tiny little thought...Yes, it was painful.

My wife gave me these for christmas a few years ago.

Click to view attachment

I asked her where she got them today. She said she got them from BestBuy. ( ?!?)
They are basic case nibblers. I usually only modify cases with a dremel, but these cried out to be tried. You can see from the bowl I used a stack block pattern going a few mms one way and then the other. You can do curves with these, but it really needs a flat piece to do it. Anyway, just nibble away at the piece until the biggest section comes out and then nibble the edges down to rough cut. Total time from start to finish. 10 minutes.

Click to view attachment
The closer side has been nibbled to the edge. The far side shows the pattern again. VERY easy and no danger of distorting the sphere.

Next just dremel of the rough edges with a grinding stone. 5 minutes tops.

Remember to wear your safety glasses!


Click to view attachment

Next comes the mounts.

Took a little detour on the mounts because of the light box I designed. Came home with a bunch or cardboard from work and started translating it to 3-D. Im trying to get a feel for how I am going to have to cut the metal for the box. As I started into it, I started to realize that this wasnt going to be as lightweight as I hoped....Hmmmmm...

Gotta go price some aluminum..

Oh Boy...Depression sets in as I realize my order will not ship for a while.

Hey! My bulb, ballsts and lenses shipped! Mad scientist time comin soon...

On a TOTALLY unrelated note, but something I am quite proud of...

I just completed my 10,000th SETI unit last night at 9:03PM EST.

SCIENCE!

10,000! wow,man
How long have you been running that?

I signed on in 2001, I think. My house is kind of a server farm so its fairly easy to do.

Started work on the protofram for my PJ last night. I get jazzed just thinking about it.!

So the bulbs are shipping, and I have come close to finalizing my design. The protoframe I will be using shall be lightweight and enforced with industrial polyester glue. Expensive? a little. Worth it? Oh yeah....

I started off with the basic frame which is going to hold the component light box. I had been waiting on some aluminium ( That spelling is for you, Punisher...) flashing, but decided since I had so many PC cases around...why not use them?

The box starts out at 7x14x7 internal dimensions. 45 degree angles joined with the polyester glue. The frame is just a 15 dollar "frame clamp". Cheap and vital for good angles.
EDIT: I decided to go with an 8 inch depth instead of 7 to give me a little more play. My gut feeling says Im going to need it.

Click to view attachment

This is the way Im joining them. 90 degree cuts. No fancy dado cuts here, just multiple trips across the table saw at different widths.
If anyone wants me to post a quicky instructional just say the word.

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The box cureing. The glue sets, expands, then bonds the wood. I tell you, this stuff makes weak wood stronger. The final framework for the component lightbox, and a happy surprise....

The glass next to it is a piece of tempered, edge softened, heat resistant glass.!
It also has a frame which I might be able to salvage. I love finding stuff like this. After cleaning it up, you cant tell any difference when its in front of your eyes. I has one scratch, but I dont think it will be in the cone.

Click to view attachment

Thats all for now... LOST will be on soon...

After building the box and working out a neat trick for the enclosure, I realized that my bulb might be too long for the box. Actually the problem was the mogul socket itself. I was banking on about two inches long. Turns out it was more like 2 3/4 inches, which doesnt leave much room for wide adjustment in the box.

After taking a closer look at the socket, I figured I could take about 5mm off of it with no problem. My 5.00 bench grinder to the rescue!

A few notes about working with these ceramics....

1. Wear those glasses! The actually ceramic itself comes out as fine particles, but the glazing can chip off and it makes for a really sharp edge. If you can do it outside or with a fan blowing any dust away from you, then all the better.

2. Wear long sleeves. The fine ceramic dust is an irritant to skin, much like fiberglass. A respirator is a good idea if you can, otherwise use the fan trick. Even a cloth around you face is some help.

3. Clean up right afterward. Gently brush any dust off the socket, then clean up with a damp cloth. Get you clothes off as soon as possible and dont continue to work in them, the dust will work its way through to your skin. It might even spread due to air moving in your clothes as you moves. There are places you really dont want this dust. Get them in wash as soon as possible.

4. Get a COOL shower. Start with the coolest water you can stand to rinse the ceramic dust off. Why? The cold water makes your pores contract and makes it harder for the dust to get into them. The same is true for fiberglass dust. A cool shower rinse will help you not wake up at 3:00AM scratching like a mongrel.
You can always finish off with warmer water after. Trust me on this one...

5. Work slow. This ceramic is pretty tuff, but if you try to go too fast, it heats up and then gets a little unpredictable.

Now on to the fun part.
I used a bench grinder with a course edge to take the socket down from its original height. If you are having trouble making a guide line, you can use a coffe can lid and lay the tip of a sharpie on it. Then just turn the socket and you will have a guide line. The lines dont take well on the ceramic, so if you touch them, they will wear off.

Pictures posted later this evening..

That sounds like some nasty stuff.
Seriously!
That kind of effort is pretty rewarding though.
Looking foreward to those pics!

You wouldnt think so. I mean, c'mon, its a big light bulb socket...
Naturally, despite my precautions, I spent a good portion of last night squirming and trying not to itch at my arms.

Pictures of the mogul base marked for a possible two layer reduction. The first was the most, about 5 mil counting the lip of the base. The second was an extra two if I decided I wanted to go that route.

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The done deal. This is a rough cut of the mogul. I still need to smooth out the ends with a palm sander. I wish I had a belt sander.

I had to make the channels a little deeper for the wires. It should work pretty well.

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Samurai,You have "blinded me with science"

"Yes, But as a noted Scientist, it was bit surprising that the girl blinded ME with science..."

One of my favorite albums/cd's. I almost named my first daughter Europa.

A few pictures of the light box Im building for the project. As I said before, I started out wanting to make the PJ componentized. The light box frame was 14x7x8 interior dimensions. Why 7 inches? Quite frankly I had no idea. It was just a figure I pulled out of the air when doing rough sketches. Well Imagine my surprise when I decided to use the leftover computer cases. 7 inches is the standard width for most computer cases. (YEEHAW!) So I choose my first victim carefully.....

SCIENCE!
Click to view attachment

Now that the anethesia has worn off, the patient/victim is much more trim and has a more desirable and compact frame. ( Sorry NIP/TUCK is one of my favs..

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And a quick shot of the inside. This whole unit slides in and out of the component light box frame I built and has a 1 inch travel for fine distance adjustment to the rear fresnel. Thats why 8 inches instead of 7.

Now to check out the new dimensions for the bulb. Im figuring a reasonable amount of room...(fingers crossed)

PS. I would LOVE to claim that I designed the lightbox from the start to match the computer cases, but I really cant say that. Not on a conscious level anyway. This is just one more example of how the universe loves to plop interesting things in my lap. This type of stuff happens to me all the time, but I cant ever seem to win a lottery. Go figure...

Damn.....it has come to a screeching halt.
This is going to sound like a personal problem, but my USHIO is crooked..( Stop it!)

Okay, its funny....You can laugh now.

Yes, my USHIO is crooked. This would explain my love for ...never mind.

I noticed when I was getting ready to do a few centering tests that the bulb was not going in very evenly. At first I thought it was because I had skipped a band and was screwing it in wrong, but I tried a few more times and got the same result. I even made sure the base was at different positions. Here is my USHIO standing tall next to a straight edge.

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Here is the USHIO rotated a few degrees ( about 90)

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and here it is rotated another 180 degrees.

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So Im thinking I might not have enough play to make up for this much variance. Has anyone else seen this much tilt?

I cant figure out if I should be thinking Leaning Tower if Pisa or whistling the theme to the Enzyte commercials....

"Blinded by Science" I think that The Golden Age of Wireless was more or less a permanent fixure in my CD player when I got the CD. That was, of course after wearing out my cassette, which I started using when I wore out the copy of the cassette that I had made. Though I must admit that for quite a while Aliens ate my Buick was further up the list for me. What can I say, I just wanted the keys to her Ferrari.

Crooked bulb: I'm on my second S400DD. This leaves me far from being an expert, but both of mine have threaded in reasonably straight. They both wobbled a bit, but not enough to cause a problem. The second bulb ended up being a direct drop-in for the first. Yours seems to be just bent... Or maybe it's kinky. (Sorry, couldn't resist. )

Yes, I have the studio 12 and the full Dolby cut on vinyl and of course the remastered versions on CD. I loved the first and Aliens was very VERY good. I cant tell you how many times I "kicked those 500 italian horses into life!"

Yeah. It looks a little crooked. I didnt keep my tolerances wide enough for this. You think I should ask Brain about it?

Mine's crooked too. Strangely, it also seems about 2" longer than yours ...

Sorry, couldn't resist.

That's why I am making my light fixture completely adjustable - the Chinese are not know for their tight tolerances (there's a pun in there somewhere but I am having a stink of a time finding it)

Actually, Aliens wasn't supposed to be brought over to Canada. The story that I got was that some women's groups didn't like "Airhead" very much, and BMG decided not to import it. I got a copy anyway. I had to special order it, though. Then my copy got stolen :angry: and I had to special order another copy. A few months later I found it (along with some other fairly rare stuff that I had) at a second-hand bookstore. I'm fairly sure that most of my stolen CDs were pawned there, some of the stuff I had wasn't very common at all. Unfortunately, I couldn't prove it...

For the bulb, you can ask Brain. I don't think that he can guarantee the straightness of the bulb, and in fairness, I don't really think that he should need to. It's unfortunate is all.

You could try to grind the base down again, the additional 2mm should give you enough space that you can wedge the base to straighten the bulb. I don't envy you the case of the itches that you'll get from grinding it again, (Try wearing a rain coat, that's what I did to take off a bit so that I could center the bulb.)Judging fromt he pictures, 1.5mm or so would be enough to get the bulb perpendicular to a surface. You can use a combination of 3 wedges to position the base on the mount, that will allow the bulb to be perfectly horizontal, though the base won't be. Good luck!

I'll admit that I was a bit worried about my replacement bulb being that crooked. I don't have much room for adjustment at all, as I have zero "extra" space for base adjustment.

Sigh. Oh well, Im not going to let the bulb thing get me down, so I figured I would work on the mount for the reflector mirror. I think I have all the bases covered. I have forward/backward from the bulb, forward/backward from the fresnel, up/down for the bulb and should have some forward and backward as well. I had originally thought up a terrifically complicated focusing mechanism based on a Newtonian telescope and then realized I didnt actually need it. So I decided to go pragmatic and do it back and forth and up and down for the focuser mirror.

I snipped out a portion of the center of one of the 80mm fan gaurds I have and started to line it up on the back of the reflector. I used the same grid for lining up the holes for the mount as I did for cutting the arcs. Even if the spokes of the fan gaurd are off axis, the holes will not be, since every fan gaurd is made to be put into a square hole array. So line the holes up with the gaurd like so:

Click to view attachment

I then used a rubber band to add tension and keep the gaurd in place while I fiddled with the alignment. Its worth it to be nuerotic about this stage. Be careful and place and recenter the grid as many times as you like. Check the side for being level and check again if you are not sure. The best thing that can happen is you end up perpendicular to the center point of the reflector and true to the cutouts. The more accurate you are here, the less you will have to adjust for later.

Ready for JBWeld:

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Now mix and apply the JB Weld ( IE liquid Steel, or any other high temp adhesive you like... I like to mix it in the bottom of a soda can since its basically just a little bowl waiting to be used. Spread it on and work it a little like caulk. Thats glazing for you guys across the pond

Check your alignment one more time before it hardens. Once it does, thats all she wrote.

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Guess I will go contemplate the nature of the universe while this dries.... or have a glass of wine.

Good one!

Uhmmmm......Actually the USHIO bulb is made in Germany.

There's definitely a pun in there, but I think were supposed to keep it sort of clean here...

As for the extra 2 inches... "Objects in mirror may appear larger than they are."

FYI:Mine is crooked too!!
I grew up with Thomas Dolby too.

looking like you are making some progress too!!
Looks like some good work.

Aww shucks...thanks.
The way my drawings look, it probably going to come out looking like a cross between a star wars laser cannon and a dental drill....


Growing up with TD was a good time...I wouldnt mind seeing another album from him..

Samurai,
The "crooked bulb" problem and the relatively unpredictability of the crookedness from bulb to bulb is what prompted my building of the highly adjustable bulb mount that you may have seen in my plog. if you look closely at the actual arc chamber inside the bulb it is also slightly off square from the rest of the glass housing... another reason to build the adjustable mount.

On the other hand, all that complexity may not matter that much. another builder took a pic of the arc chamber and noted that the arc may form across the top of the chamber, and does not always form right throught the center, so there's that. if you take the bulb back out and bend the center contact clip in the mogul base down, the bulb will still make good contact, but the (flimsy) screw threading of the sides will not bend as much and your bulb will be mounted straighter. that alone may make enough difference that you won't need to go to a crazy adjustable mount.

Great work on the frame and shell building!! it's starting to come together!
hope that helped...

I actually took apart the mogul last night to see if reversing the cage would work. No such luck. I was also thinking about one more brass shim on one side to tilt the holder. Might make it a little straighter. Thanks for the kind words. Im sure I will beat this...eventually.

I have a peculiar idea, but I need to check with a friend first....

Touche ... !

Well, on my way home, my cars fan decided to do something and get out of balance. It sounds like I have a huge vibrator going under my hood when I want A/C. Its kind of embarrassing, but it does draw some interesting looks from the ladies....

Wanting to see SOMETHING concrete today, I decided now would be a great time to take some temp measurements for the box. So I whipped up a quick base and wired up the LL ballast.

Click to view attachment Yes, its the bulb...

Made sure I was one a clean circuit, checked my wiring for the third time and then told the wife I was going to fire it up...mmmmmm. Its like Heavy Metal all over again..the wierd green glow

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Then I started taking temps. I used a basic digital meat thermometer and left it in the top of the box, 1 inch away from the surface of the bulb. I kept the bulb on for close to an hour and hit an interior ambient temperature of about 170 degrees.

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Sunsequent readings indicated that the bulb was much hotter than I had first thought. I tried to get some readings and accidentally touched the outer shell. As the smell of burning teflon began to penetrate my senses, I noticed that the thermometer read 279 degrees and was climbing. Aaahhhh!

I am now contemplating a metal halide barbecue grill/projector....

Nice lamp. Brighter than all hell. What I forgot to mention before is that since I like to do a little astronomy here and there, I have been training my eyes for very low light. The headache I have now is mild, yet a painful reminder that if the sky is clear tonight, it still wont do me any good.

Gonna take a break, shower, watch HOUSE and enjoy my wifes teasing about how geeky I am.

Well, just for the fun of it I consulted a friend and he slyly gave me the technical support number for USHIO. I got in touch with them but all their techs are at a conference. They are going to call back to discuss an alternate mounting scheme.

Good thinking.If in doubt..ASK!!

Yeah with at least 300 degrees F surface temp, I dont see a whole lot of options for this one except for custom ceramic disks. I can make them, but its gonna be a pain. Someone mentioned arc from the bulb itself. I dont think thats a realistic fear since its already insulated by two layers of glass, but the heat build up could be just as damaging. I did also notice that mogul bases are often described as arc shields, so I figured I might want to talk with one of the techs who designed the bulb.