.

06/22/15 more Photos in the bottom of the OP.

06/12/2015 - A package "should come next week", with two pieces of something about 24" around and XX inches tall. Hope it will work for a sphere. If not, maybe for helmets or pygmy bathtubs.

06/09/15 More thoughts - I think I am shooting at too big of a sphere. Well, I don't know, but I figured a big sphere would be needed for a light having 15,000 to 20,000 lumens, but I really don't know at all. I haven't a clue as to figure out just how big a sphere is necessary. Sorry to say, but it is all just a SWAG for me and most likely totally wrong.

I do know I want an 8" or 10" portal for the lights and I am also figuring a 2" portal for the sensor. If I use the "5% rule" for how much surface area can be used for portals, in a sphere, then I would be looking at a smaller sphere, to satisfy that requirement.

I did some calculations. Well, the Internet did some for me, as I can barely add 2+2 and come out with 5. Luckily, you can find most anything on the net.

So,

Surface area in Sq in,

for different spheres, (rounded) and 5% of those numbers

16" - 804 40

24" - 1,809 90

30" - 2,827 141

36" - 4,071 203

Then I find the Sq in for the holes I might use and since I will use a 2" hole for the sensor, that will be consistent in all the results.

Sq in for holes plus a 2" hole

4" - 12 + 12 =24

6" - 28 + 12 =40

8" - 50 + 12 =62

10" - 78 + 12 =90

12" - 113 + 12 =125

So, if I want an 8" port plus a 2" sensor port, then I could get away with a 24" sphere and still fit within the 5% rule.

Maybe I am just going for too big, because there is stuff out there at the 24" size and it's a helluvalot cheaper than the 36" size.

Guess I need an Integrating Sphere professor to come tell me what I need, well, besides a $30,000 real integrating sphere.

---------------------------------------------------------------------------------
Well, it's a disaster on the IS. I finally got one layer on and let it dry. Then I put on a second layer and when it dried, I got several large buckles in the outside. The best way to describe them would be lines of raised area similar to an earthquake, where one edge heaves up and the other depresses. There were also cracks and while it would be grand to figure out why, I won't bother with that. I think it's simply loss of air in the ball, or expansion and contraction of the ball, due to the large variances in temperature in the garage. No matter what, it is not acceptable and after three days working with it, I am not willing to @#%@ with it any more. Simple as that.

Well... Start it for sure

Almost everything is here, waiting on me.

The ball is 34", but when I pumped it up and used a higher pressure, (about 40psi), it's closer to 36". It's an exercise ball from Amazon.

The LX1330B came from Amazon as well. Lots of the items here came from Amazon Prime.

A few copies of the Dallas Morning News and a whole bunch of Glue. Wouldn't want to run out!

I will try rolling the surface, but I have brushes just in case. The big roller won't work, but I will try to cut it into four sections and use short rollers. I have to mod the roller handle too.

Once the Papier-mâché is done and cut in two, I will use Kilz as a primer, on the newspaper, inside and out. Hopefully, it will keep the print from bleeding out.

The actual coating of the sphere will be Titanium Dioxide, Water and Water based Polyurethane. 1 cup powder, to 2/3, or less, cup water and 1/3 cup water based Poly. The Anatase hasn't come in yet, so I just copied a photo of it off the net.

Whatever you do, don't try snorting this stuff! I hope the cops don't come to the door when I start mixing.

I plan on starting with waxing the ball. I want to try to save it if possible, so I will wax it and when the paper-mâché hardens, I will deflate it and hope I can save it. I'm not going to worry about the ribs in it. I will just consider them lines of latitude instead of giving them attitude.

So, that's all for today. I'm starting all these projects because I'm unemployed now and I figure if I start enough of them, I will find a job and have to put them all on hold. I am counting on Murphy's law.

------------------------------------------------------------------------------------------------

06/07/15 Well, it's shaping up to be one of those days. I happened to look on the Elmer's glue website at a video of someone doing papier mache on a balloon and they say do the first layer with just water and then start the second layer with 50/50 glue and water. Ok,

Once that layer dried & fell off the ball, @!#$!!@#$$#@, I filed it for future reference.

Second try with 50/50 glue and water. Well, it's sticking better, but I have to wait till it dries some before I can rotate the ball. It's heavy enough that if I try it wet, the ball flexes and the paper starts moving.

Fun? WOW!

------------------------------------------------------------------------------------

06/17/15 - The security domes arrived today.

The half, (Well, Almost half), spheres are made of plastic. It looks like ABS to me. Said Acrylic, but looks, feels and smells like ABS. ABS can be plated and I think that's what it is. That's good, because it will be easier to cut holes into.

As you can see, ti's not a perfect dome. I also have some of the hard foam used for lining tool boxes, that you can cut out for tools to fit in. It's hard enough to retain it's shape and not compress. I will use it for a center piece between the halves, to hopefully form a better full sphere.

Lots of stuff to do here, not including flashlight related things, but with the weather being constant rain and very high humidity, I can't do much at all except wait it out.

-------------------------------------------------------------------------------

06/18/15 A start, finally.

I decided to go with a hole of 7-3/4" in diameter for the main portal. I used a compass with metal tips, to mark where I wanted to cut. You can alomst, barely see the ring where I marked it out. I did find this plastic is Acrylic, but a very soft type of Acrylic, so it must be highly modified. I decided the best way was to cut it with a hot tip, but how to do that?

Well, it just so happens that my trusty torch comes with soldering attachments, which I never use, so I modified one with a file, to make a small blade like tip. These tips hold heat for a long time, due to the mass in them, so it should be easier to cut the hole out.

I tried it out on a straight cut first. It works fairly well, so it's off to do the circle cut.

It's working better that I expected. About time, with all the issues I have.

One giant gaping hole ready to clean up with a dremel bit. I cut just inside the line, so I can hopefully end up with a smooth and fairly round hole.

Time for making the other portal for the LUX sensor. What the heck is this? That's not 90 degrees. 90 degrees would be down on the seam. Is this messed up or what? We will discuss this in a minute... The photographer refused to show herself, so she made me gray out where she was. Shy girl that she is.

OK, so I am cutting a hole for the sensor, in a place where it shouldn't be. Well, a long time back, when I wanted to do this before, I decided on an unorthodox location for the sensor, but it was based on information from Labsphere. I have pasted some of it here and I reference this link, to a pdf file from Labsphere. Taken from their Tech Library. (Yes, I checked and information found in that doc can be copied).

4.7 Geometric Considerations of Sphere design

4.7.1 Source Geometry

Sources can be separated into three types:

Omni-directional- sources that emit light in all directions

Unidirectional - sources that emit in one direction;

• Partially directional - those that fit somewhere between unidirectional and omni-directional.

The design challenge is to make spheres for each type of source that allow for accurate and repeatable measurements.

The first consideration related to source geometry is ensuring that the source does not directly illuminate the detector. This may mean that the designer will place a shield or “baffle” between the source and the detector. In other cases, it simply means that the detector needs to be located in a portion of the sphere that is not illuminated by the source.

The following are some typical designs that can be used for these types of sources. Most sphere designs can be based on one of these designs as long as the source geometry is correctly defined and identified.

Omni-directional Sources

Many light sources, including commercial lamps, provide general illumination. The total luminous flux emitted by these lamps is more significant than the intensity in a single direction. The integrating sphere offers a simple solution to the measurement of total luminous flux (Figure 12). In this design, the test source is placed inside an integrating sphere in order to capture all the light emitted from it. With a properly calibrated system, this geometry yields very accurate measurement results.

Unidirectional Sources

Some light sources, including lasers, are highly directional. These sources may be directed through an entrance port on the sphere (Figure 13). Although extremely highly directional sources could be measured directly by focusing the laser on the detector, the integrating sphere offers several advantages over the simple detector approach. First, the integrating sphere eliminates the need for precise alignment of the laser beam. Second, the sphere uniformly illuminates the detector eliminating effects of non-uniformity of the detector response. Third, the sphere naturally attenuates the energy from the laser. This attenuation protects the detector from the full strength of the laser and allows the use of faster, more sensitive detectors.

Sources that are neither Omni-directional or Unidirectional (I believe that LEDs fit this category) Other light sources, including laser diodes, fiber optic illuminators, fiber optics, and reflector lamps are neither highly directional nor omni-directional. These light sources can be placed near the entrance port of the sphere so that all of the light is directed into the sphere. The sphere spatially integrates the light before it reaches the detector (Figure 14).

I consider a LED, (the type we use in flashlights with 115* to 130* angle of illumination), to be neither Omni-directional, nor Unidirectional, so I see no reason not to use the Figure 14 diagram for sensor placement.

That's it for now. I won't be cutting the hole till tomorrow morning.

-----------------------------------------------------------------------------------

06-19-15 -

I cut the hole for the sensor tube just like I did with the big hole. I used 2 part epoxy in a putty form, to adhere the tube to the dome. I have used this putty before and it holds to just about anything, even under water and it's very handy for something like this.

There are several brand names of the putty. This one is white and it is the Loctite brand. I also have a tube of liquid nails, which I use for different projects involving plastic or wood. The big tube is for the foam insert, to glue it to the halves of the sphere.

I got this 24" x 24" square of foam insulation from Home Depot. I don't know what type of material, but it has absolutely no air pockets in it. It's as solid as soft wood and it can be cut with a razor knife, leaving a fairly smooth surface, if you are careful.

I used a Stanley Tools 10-049 knife, to do the final trimming to size and then I used 320 sandpaper for wood, to make the final finish. I think it will make the sphere almost round now.. It was 21-1/2" in diameter one way and only 20" in diameter where the halves met, so now it's 21" with the foam insert.

All sanded and ready for paint.

I used Rustoleum Primer & Paint from HD. I used gray for the undercoat and this brown for the top coat.

Now, it's time to work on the other half. I figure it will take 3-7 days before I can start on the inside, to let this paint cure fully on plastic parts.

----------------------------------------------------------------------------------

06/20/15 - Painting the primer coats and other stuff

I have been making covers to go over the large opening, so I can use different lights.

I cut the discs out of 22ga metal, then I split them and cut out the centers. I still need to use the dremel, to clean up the centers, but it's down for repair, so it will have to wait. As you can see in the photo below, I will form them to simulate the shape of the dome. I also have to find some black rubber, to cut more discs, to fill in when a light is not the same size as one of the metal disc openings.

Ready to try priming the inside. 3-7 drying days almost lasted 24 hours, before I just had to get after it.

After one coat, the gray still shows through.

Now, it's three coats and I think that will work. I have two coats on the other half and I should be ready to try the final special coatings next week.

Even the insert has been coated and it took paint better than the domes did.

That's all for now.

-----------------------------------------------------------------------

06/21/15 - I went ahead and did a couple of coats of "the mix", to the sphere.

I mixed 200 grams of Ti02 with 120mL of water and 80mL of water based polyurethane. I poured it all into a jar and shook till it was mixed. The powder is just about the consistency of flour. I figured it would be thick, but it wasn't. It was more like a white wash, than a paint.

But, Damn it's White! I thought the white primer looked good. I was even thinking of leaving it like that, but what a difference. When I was applying it, the primer looked light gray in comparison. Now I know why they use this stuff. The gray in the photo is just shadow, because the light isn't direct. Anyhow, it also dries fast. I put on two coats one after the other. I imagine it's the Poly that dries it up so fast. I will leave it and go with two more coats, but I may use even more. I can see gray spots here and there, so I will cover it till there are none.

--------------------------------------------------------

06/22/15

The painting is all done. I give up. When the paint dried inside, it crazed like when you heat an old bottle to craze it. Looks like S___. Nothing to do now, but put it together and see what happens. I imagine it will be useless, but there's no fix. Can't remove the paint from a plastic sphere. Probably a reaction between the polyurethane and latex, but it's all over now. I glued the two halves together. No insert. That didn't work out either. Warped from the paint.

I will let you know what happens, but I don't think this is going anywhere except landfill. I expect the paint to flake off in a day or so.

Thanks for putting up with all of this, "how not to make a sphere". Never said I was good at everything, point is case here.

----------------------------------------------------------------------------

Reserved

Hey Hey! It’s about time! :slight_smile: I love your write up Old-Lumens. I’d be making one along with you, but I already made one.

Does it turn blue?

This should be interesting! I think Kills will be a good primer, interesting read HERE on latex paint vs oil if you have time…

Personally, I don’t think this will be big enough for your next monster build :wink:

It won’t be big enough for one of the last ones I did, but it will have a 6" opening in it. Still less than 5% of the total surface area. Ought to hold most lights easily.

But your lights don’t fall into the “most lights” category :smiley:

Very cool OL!! How do these things work? I'll have to look it up.

Integrating sphere

Well, it's a disaster on the IS. I finally got one layer on and let it dry. Then I put on a second layer and when it dried, I got several large buckles in the outside. The best way to describe them would be lines of raised area similar to an earthquake, where one edge heaves up and the other depresses. There were also cracks and while it would be grand to figure out why, I won't bother with that. I think it's simply loss of air in the ball, or expansion and contraction of the ball, due to the large variances in temperature in the garage. No matter what, it is not acceptable and after three days working with it, I am not willing to @#%@ with it any more. Simple as that.

Some things, well, many things, I cannot do or deal with. This is one of them.

I failed with the paper mache method too, it never got stiff enough and when finally coating the inside, the paper began to crumble up .

I used styrofoam balls since then. These also have their challenges, but they could be handled a lot easier.

I understand you were trying to build the Integrating Sphere, but what is the goal of this step? Simply building a rigid spherical structure? If so, have you considered chalk? It would end up kind of fragile and on the heavy side, but MAYBE it could do.

Unfortunately, I cannot find a foam ball in 36", in the USA. The people carrying them, do not carry them any more, because there were not enough sales for them. Anything smaller will not work for the big lights, due to the “total surface area vs the combined port area 5% rule”

What’s the quote regarding the proverbial Murphy’s Law ?

:arrow: ” If something can go wrong , it will go wrong ! ”

( Does anybody really know who Murphy was ? ) :wink:

It’s not a fail!!!
A fail is not accomplishing something because you didn’t even make an attempt. This is an experiment which didn’t produce your desired results.

Hey OL would this globe led lamp work?

This one is 19”
http://www.dwr.com/product/globe-portable-led-lamp.do?sortby=ourPicks

Another idea is to make the ball using a round balloon and paper mache kind of like this, maybe instead of newspaper you could use white printer paper…

Or for more professional results contact a place where they make Mexican Piñatas and ask them to build you one, would that work?

Just my $0.02

The styrofoam balls here in Europe go up to 50cm outer diameter (~20inch), that is not big enough either.

Does it have to be foam?

This might work. Order in white ask them to drill the holes in price quote.

Ooohh, I Like that! You must be a motivational speaker. I put it in the title line.