Workshop LED Panel Light Build Part 1

Workshop LED Panel Light Build Part 1

This is one side my workshop. Most of the light for turning comes from a
twin fluorescent attached to a shelf just above the lathe. When the lathe’s cover is on, I also use
this bit of space for taking video and stills using an old roller blind as an infinite background. Whilst it’s generally ok for machining,
for anything else it has a couple of big problems: The first is that it uses a low frequency
magnetic ballast, which under certain conditions creates loads of flicker. I’ve a feeling that some cameras are able
to phase lock to mains lighting to stop the hum bar running through, but my little Panasonic doesn’t appear to do this especially when there’s a lot of motion in the frame. Here I’ve wildly exaggerated the problem
by using my 60Hz phone camera with the 50Hz light so you get the idea. The second issue is the colour is really horrible. To try and demonstrate, this is North Yorkshire daylight in February. Using the same white balance this is how the strip light looks. It’s a horrible yellowy brown colour. Obviously, white balancing on the fluorescent before starting filming helps. But although this makes the white look better,
the colours are always a mile off and it takes loads of post processing to try and make things look something like right. So that’s why I want to replace the light. The difficulty I had was the runner for the
up and over garage door runs right where the light is going, meaning I’ve absolutely
no more than 29cm to play with. After some searching I settled on 18 Watt
LED panel lights. These are 225mm square so fit nicely into
the space available. And they seem pretty bright and evenly illuminated. I was curious to know if they were edge lit
or back lit, so I had a look inside… Under the steel back panel there’s a couple of layers of foam, a reflective sheet, a piece of textured acrylic and then a diffuser. The surface mount LEDs are mounted on a tape stuck round the inside edge of the aluminium frame. I imagine this is supposed to act as a heatsink,
but the contact with the LEDs is pretty poor in places. The drive was just over 55 Volts, drawing a current of just over 280mA. I reckon that makes it nearer 15 watts than 18 but I’d rather it be under run than over, as hopefully it’ll last a bit longer. I counted 90 LEDs in total, which got me wondering how they’re all connected. Looking at various similar adverts for this
type of panel, they seem to come in increments of 3 watts and 15 LEDs I can’t be sure this is right, but the numbers seem to add up: You’ve 55 volts at 284 milliamps. There’s a series chain of LEDs: one through to 15 And this is repeated 6 times in parallel The 284 milliamps is split between 6 x 15 LED chains, giving 47milliamps per chain. The 55 volts is dropped across 15 LEDs, which is about 3.6 volts per LED 47mA with a forward voltage of 3.6V feels about right. Given how little there is to the power supply,
I’d expected the output to be fully of spikes and jaggies, but apart from a bit of 50KHz
noise it’s actually pretty clean DC. The upshot of this, is there’s hardly any flicker. Remember the 60 Hz mobile phone footage? This is the same shot using the LED panel And the colour’s miles better too. Remember the dirty orange from the strip light? This is the Yorkshire daylight white balance,
with the LED panel as the light source. There’s a bit of a greeny blue tinge, but it’s nothing like as pronounced. Anyway, that’s enough about the light that
I chose. On with the build… I had a few lengths of 1/2 by 1 inch rectangular tube in stock that I pulled from a skip. They’re all 1.7 meters long. Unfortunately, 8 x 225mm LED panels adds up to 1.8 meters long. About a year ago I bought myself a little
80 amp inverter welder, with the intention of teaching myself how to use it. The truth is it’s hardly been out the box. But that missing 10cm seemed like a good opportunity to try it out. When I got the welder, someone who know about these things warned against keeping the rods in my damp garage. So I kept them in a sealed tube in the house. And somehow they’ve still managed to become rusty and powdery. But that’s all I had. And they’d had to do I cut a piece of tube to extend the length, set it up in the vice and made my first weld… It won’t win any prizes, but a wise man once said: “You never learn anything by doing it right first time”. About 5 rods and 20 minutes of grinding later,
I managed to fill in the hole! Now I had two long pieces the right length I joined them to some shorter pieces to make a long narrow rectangle. The welding was still more miss than hit,
but with enough practice one day I might graduate from hopeless to poor. Once it was all stuck together and cleaned up, I added some paint to try and keep the rust at bay. By now, you can see what I’m aiming for. Originally I was just going to screw the fame up, but then I thought giving it a bit of adjustment might help manage glare and reflections. I was going to try and make something from scratch but then I came across these mending plates My plan was to make interleaved fingers into a position lock, that could be set with a handwheel First I opened the end holes to clear an M6 screw Next I used a countersunk screw so the nut would self-centre over the hole. Given the limited success of my welding, I figured silver solder would be a safer option for this bit. Next I trimmed some of the brackets down to make spacers to layer between the T pieces. This is how the plates will fit together,
with one end fastened to the light frame and the other to the shelf above the bench. A quick dust with paint finished this part off. To actually attach the position lock, I used a scrap of steel angle iron that I drilled and tapped M4 on one side then drilled and countersunk the other. To finish off I used the last dregs from my paint can. Once the paint had dried, I assembled the parts drilled the frame and attached the position lock The panel lights are supplied with spring
clips for fitting which probably work well in a plasterboard ceiling but they didn’t suit my tubular frame. I’d initially thought I’d just put holes
through the front of the panel and fit screws but this seemed a bit crude. I took some inch aluminium angle and reduced it on the mill. I marked off 20mm sections and cut them off. I’d need 16 brackets plus a couple of spares so I ended up with about 20 all together. To speed up finishing the hack-sawed edge I cobbled together a thin vice stop from some junk I had lying around, and then set to trimming the brackets. To give me some extra adjustability I went for a
slot rather than a hole for my fixing screw. That was the next operation. I cut a couple of slits in the brackets to
make retaining tabs. Hopefully these would stop the brackets falling out all over the place when I started the assembly Two of the brackets didn’t get slotted: I drilled a small hole instead to just clear the point of my centre punch. As some of the lights were slightly different sizes I marked, drilled and tapped the fixing holes as I went along. Finally, it was starting to take shape! Next I stuck the power supplies to the back of the panels with polyurethane glue and I weighted them down with what I had to hand until it set. Whilst the glue was drying, I made up a couple of aluminium brackets to hold a terminal strip in place. And that’s it for part 1. Thanks for watching! Join me in part two if you’d like to see
how I get on with the rest of the build…

14 thoughts on “Workshop LED Panel Light Build Part 1

  1. Subscribed. GOING NOW to watch, like, and comment on each of your other videos to help promote them. Without question this is some of the best produced machining/DIY content on youtube!

  2. The title of this project belies its quality and complexity. Well worth watching but nearly didn't because it sounded too simplistic. Excellent narration; some YT narrators replace "removed one jaw from the vice" with a detailed explanation of what tools were used to remove the jaw, the time it took then a further explanation of the replacement of the jaw. This is my sort of YT channel, clear, concise and thoughtfully produced. I have subscribed. Thanks for the good work.

  3. a tip for filling holes burnt through from someone who has done lots of welding for more than 40 years. only recently i blew a hole in something i was working on and after all these years i thought of using some filler rod as you do in oxy welding. i went and got some heavy gauge tie wire and poked it in the hole before i struck the arc. quickly fixed. i wasn't welding high pressure gas pipelines so no cares about structural integrity. coat hangers, not plastic ones, would do the job as well.

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