I never thought I would see the day. A perfectly working modern fluorescent fixture over the table saw came down to be replaced by an LED fixture. How it came to pass........
For the WW Club presentation I have been doing a lot of conferring with the design staff of local lighting store. It seemed that LED Troffer fixtures could be an attractive option for shop lighting. Troffers are designed to attach to a ceiling to light rooms with shadow-free light.
As an experiment and demonstration for the program I bought a 2 x 2' for $46 4100K; 90+ CRI; . I hooked it up to a portable extension cord and moved it about the shop to investigate lighting various tools. When I hung it over the table saw I measured 55 foot candles at the top, and shadow-free. After the program it had to go somewhere.....
I later permanently fastened it to some wood brackets with "S" table top clips and screws, not a conventional means but it worked. Next in line will be one over the dimly lit drill press and lathe.
I recently had two of those, except there were 2' by 4'. Got them at a freight auction In a big pile of stuff. Hooked them up to prove they still worked. a friend saw them and lusted after them. I gave them to him for his shop, but I am suffering a bit of remorse over the transaction.
They are remarkable fixtures. When I saw them, I assumed they would look like a bunch of little dots of light, but they don't. Nice even light. I did have a hard time finding the output in lumens or any info on CRI.
BT: is that an older Uni-saw with the Jet Lock fence and the "old style" Uni-guard I see? When I bought my now sold Uni-saw back in '87, had the same guard set-up. The disappearing splitter really was useable. I opted for the high/low position Uni-fence for the saw.
I regard it as a superior fence to the new style. I can easily screw stuff to it and most important lack my hand on it by riding it between 1st and 2nd fingers for ripping.
For those installing lighting for tools like tablesaws with shiny flat tops, one thing to keep in mind locating the light fixture so there is no glare reflected into the eyes at all working. One with a mobile base may need special planning. I temporarily positioned my T5 fixtures to test for glare before mounting permanently and wiring. Yours looks ok.
Buying a LED fixture with no information could lead to buying ancient LED technology of blue, low CRI light and not much of it. I measured a world of difference between quality LED fixtures in the lighting store and the $20 "bargains", that were likely ancient technology outlet sale items.
I was not smitten by LED technology until I saw later versions of it- high CRI, any color temperature desired, sophisticated light management to direct light as designed, focused or diffuse.
The High Bays are like a search light shinning down from above. As you point out reflections are to be accounted for. A Troffer is designed to bathe tables and desks with diffuse light.
We've been installing these (or similar) in our county offices for a year and a half now. Link below.
The diffuse light is because you can just barely make out that the panels are edge-lit acrylic. We've had to install dimmers in several instances for the 36W panels in lower (8-9') ceilings due to complaints from office staff.
>>>The High Bays are like a search light shinning down from above. As you point out reflections are to be accounted for. A Troffer is designed to bathe tables and desks with diffuse light.
That's not logical. If the surface of the table saw is highly reflective (as is my cabinet saw) and in the wrong place there will be a reflection of the light from any fixture. The geometry of the source, reflective plane, and eye position is all that matters. The intensity at the eye of reflected light along any direct line is dependent only on the distance and the diffuse properties of the reflector surface. (And, of course, the negligible effect of the atmosphere unless the dust collector is not working. Ha!)
Someone designing shop lighting from scratch just needs to be aware of this. If already installed, immovable, and glare is a problem, I'd probably use the ROS to create a diffuse reflective surface.
I think you are going to have problems using a diffuse light source over your lathe. You will find you need point sources to properly delineate the curves you are trying to shape and the scratches you are trying to eliminate.
Are you recommending that only point sources of light should be used to illuminate lathe work?
The option of task lighting is always available as needed to supplement general lighting. For example, I turn on an overhead light at the opposite end of the bench from the vise, while diminishing the light over the vise, when sawing to scribe lines. At the lathe I have a PAR lamp on a magnetic base that mounts to the lathe bed to point light where needed (I rarely need it).
Not my implication at all. You're doing it the right way. At my lathe, I have about 9 GU10 spots that i can turn on and off and reposition individually, in addition to general overhead shop lights. My comment is mainly directed at people reading this who might be setting up their first lathe. If they are having trouble seeing the shapes they are turning, just adding more lumens is not going to help a lot.
>>>If they are having trouble seeing the shapes they are turning, just adding more lumens is not going to help a lot.
You say it well.
I also use a combination of diffuse light and point-source tasks lights. With fine work at the lathe, the task lights make a big difference in being able to see and judge the compound curves at the lathe and, as you mentioned, see both the scratches and other defects such as ripples. After years of this type of lighting I would hate to work another way.
I'm convinced that at least some of the defects I see in the other's work is due to poor lighting, bright or not. Some defects are not detectable until the piece is removed from the lathe and turned in the hand under better lighting but by then it may be too late.
A big mistake is to use only ceiling fixtures for diffuse light - whether bright or dim doesn't make much difference. Many turning clubs have horrible lighting at the lathe since they are in large room with high overhead fixtures. When I do demos I usually take a task light on a magnetic base.
The worst is diffuse light from above and behind the head. Even point sources coming from beside or behind the head are also not much help - anyone who's gone go caving or walked around the woods with just a headlamp knows that shadows that would show the irregular ground from the side light of a hand-held flashlight are gone. To see shadows the light is best from the sides, preferably at a glancing angle.
Another thing I find helpful at the lathe is several task lights of different color temperatures coming from different angles - this would be a horror if trying to photograph but helpful to evaluate curves if you have good color perception, although subtle.
At my lathes (and bandsaw) I have bright overhead fixtures and also several task lights on moveable arms to reposition as needed.
This shows five of the six "point source" lights. I have them all on one wall switch and can move or turn off some if needed for scratch/defect detection.
8' long T5 fixtures not shown provide general working light. My overhead fixtures are controlled by several wall switches so I can turn off various fixtures as needed. This shows a second lathe with the overhead lights turned off.
