From the beginning, I expected that my DIY surgical-style task luminaire* would need to be suspended from the ceiling somehow, because it is large by nature and I can't spare floor space for a stable stand with a big footprint. A fancy arm with a bearing in the center which hugs the ceiling like the medical units would be the preferred implementation, but also requires a lot of time and a bit of expense for additional materials.
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Since the whole point of this project was to hack together a prototype to find out whether the idea was even worth pursuing in earnest, I looked around for ways to temporarily rig a floor stand or the like to emulate the ceiling-mounted arm, so I could swing the light around the room, figure out placement, and whether the maximum possible length of the arm was actually a good idea or not.
I happen to have a 'Stolmen' pole (Ikea product) lying about the house seeking a purpose (a gift from The Alley Gods), so I improvised an arm from steel stock I had lying about, and attached it to the pole using the two brackets which happened to come with it, as seen in the image to the right.
This did the trick, and I now know that with the right length of arm in the right location, I can swing this light around virtually my entire shop, allowing it to illuminate my welding / grinding area, my work bench, my drill press, and my mill. It doesn't reach the lathe, but that's a non-issue, since the lathe already has its own excellent lighting.
So this turns out to be a big win.
When I return to work tomorrow, I'll pick up some bits and bobs to build the central ceiling mount and pivot (plumbing pipe floor-mount flange plus a few bearings I had lying around).
I'm not sure what the arm proper will be made from. I will probably have to buy up some thin wall rectangular tubing for that purpose, since the test gantry arm I built has an 18" profile, and I'm looking to keep the entire arm height within six inches of the ceiling, just because the new, bigger, better fixture will be two feet across (!) and since my shop ceiling is only 8.5 feet or so, and I'm over 6 feet, the math has my head colliding with the fixture no matter what I do. I am seriously considering removing one or two of the existing fluorescent fixtures, that's how much I am loving this new task light.
Perhaps I should amplify on why I think it's so spiffy.
1. wall plug efficiency / luminous efficiency
The unit uses "90 watt equivalent" PAR-38 format LED flood bulbs which consume only 14 watts each. Although the cheap bulbs I bought have lousy efficiency compared to other available LED bulbs (68 lumens / watt) this is a vast improvement over the 10 lumens / watt of incandescents.
The final implementation will use a yet-to-be-determined, possibly COB† light source with a more modern efficiency of 100 to 130 lumens / watt. While better efficiency than that is becoming available as I write this, those are still specialty lamps with a specialty price I'm not interested in paying. Remember one of the design goals is to make this thing vastly cheaper than a real used medical lamp.
The next one will use smaller, more efficient, more modern bulbs, probably in a PAR-20 (or so) size. There will be a lot more of them - almost as many as I can fit in the available space of the disk, not just in a ring - and they will be of lower wattage. The thing is bright enough as it is, now I want to make it more shadow-free and more efficient.
2. quality of light
The light isn't yet as shadow-free as a big surgical light is, and it may never be, because I can't spare the ceiling height, and it WILL NOT be mounted at a height where I can smack my head into it. But the multiple large sources on a large diameter really do help, since there are 5ea 6-inch sources on a roughly 18-inch circle.
The unit having more sources filling in a large disk will create one giant source which should be much more shadow free.
The next one will be as big - in diameter - as I can make it without hitting my head on it. So I'm going to build the mount and arm for it first, since how good a job I do on that will determine how big I get to make the fixture.
Very notably, the Mod.2 version will also have a 0.5" square "egg crate" grill (made of thin aluminum, sold for air return grills in suspended ceilings and sprayed flat-black) in front of the bulbs to nearly eliminate glare without significantly impacting the quality or quantity of light on the target area. To describe its effect from another perspective, outside its cutoff "cone", the grill completely, 100% eliminates spill.
3. quantity of light
The prototype unit spits out a total of 5,000 lumens, IF the bulb packaging can be believed. This seems entirely adequate. I'm designing these things to illuminate a work area of about 3 to 4 feet across, from a distance of 4 to 6 feet away. Note that this is a much larger work area than surgical lights illuminate; their work area is typically only a few inches across, with as much or more light - they are truly intense.
Working with this sort of light does wonderful things to one's vision. For starters, it causes your pupils to shrink to their smallest size, and this dramatically improves spatial acuity and depth perception, just like stopping down the lens on a camera does. Compared to even the cheapest cameras that humans can build, our eyeballs are, quite frankly, lousy optical instruments! Giving them all the light they can use significantly improves how well they work, and this lowers eye strain and brain fatigue. Frankly, you will like it if you try it.
It's hard to overstate my enthusiasm for this project; having adequate, good-quality work light has been a bugaboo - one of the banes of my existence - since I first picked up a plastic hammer and started banging square orange plastic pegs into green triangular holes while I was still in diapers.
I am literally wondering if I could put together some really good ones and sell them for a good profit. I'm keeping track of what I've spent so, 5 minute with a calculator after I've finished The Real Thing, I will know how outrageous the price tag would have to be. Just estimating things in my head, I am cautiously optimistic.
Obviously there will be more on this as it develops.
Oh, and I'm gonna go out and make a simple video showing what kind of reach a 4 foot arm / 8 foot sweep provides in my shop. (If I make the arm any longer, it won't clear shelves and crap along the walls) That should be up here within the hour...
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*honestly, isn't that a lovely word for "light fixture"? I picked up the
term during my time in theater, in the days of my wasted youth.
†Chip On Board - this refers to a high-efficiency method of constructing
LED sources, in which multiple small "exciter" (blue light) chips, usually
of less than 1W ea, mounted in close proximity to a circuit board, then
all of the chips are coated together with the yellow phosphor coating
which creates the white light.
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