so I recently came into an old but perfectly functioning floor standing drill press and as with my usual LED light obsession, I had to convert the attached light to LED. It also gave me an excuse to use my new to me bandsaw (and to use the lathe to make bearing rests for it!) and try out some different things on the lathe.
First the pill (electronics will come next year). Scrap alu plate of some description (dumpster find)
Rough cut with my bandsaw (bearing rests worked a treat!)
Drilled for an arbor, which I really should have faced first
Circularised, tapered to fit the light housing (ish) and polished for a good thermal interface
After I drilled and tapped all the various holes (using my drill press, woohoo!), I re-mounted the pill to face and polish it flat
Ta-da! For the drive current I'll be running this at, it really wasn't necessary, but I wanted to try facing and this was a good excuse.
LED star mounted to show you what it should look like. I have to reflow the LED onto the star, but that won't take any effort
In the light housing
Other end. The driver will be free-floating in the space between the pill and the switch
First thing to do, reflow the LED I wanted onto its star. I'm using a Nichia 119 LED (from Texaspyro) for this light as it's bright enough, cheap as chips (~$1 each!) and has really high colour reproduction, which is always nice to have. The 119 LEDs have only 2 pads (+ and -) compared with the more normal 3 (+, - and thermal), so the stars need the central thermal pad grinding out otherwise the LED will short. Small dab of solder paste and onto my random piece of alu reflowing plate - this is mainly to stop them falling through the rings and getting scuzzed up with the dried up rice boilings over underneath. It also makes for a nice gradual heating up of the star and LED too.
after
The 119s are the small one, the other is an XM-L2 that I thought I trashed getting a torch apart (1st pic) but turned out to be fine when I reflowed it onto a new star (2nd pic), which I was pretty chuffed about.
LED on heatsink
Wired up to the driver, one I had lying around from an old 12V LED bulb
Switch wired up. One wire from a spare 12V wall wart is screwed to the switch, the other passes through direct to the driver. The wire from the switch isn't wired up yet
Everything installed in the light, with 25deg optic to focus the fairly meager output as efficiently as possible. I measured the current and it's only 170mA, so output is probably ~50lm or so. If this isn't enough, I can always use a 5V wallwart and a couple of 350mA 7135 chips, like I've done in another work light.
Next up is making a new mount for the light. It was previously mounted on a block of wood bolted to the drill press and wired directly to the motor. I thought a more elegant solution would be to incorporate a 2 output socket into the mount, so that I could add another light on the other side in the future. I used some seriously hard mystery wood (my band saw laughed and my jig saw cried), drilled and "milled" out a cavity and various other holes, then painted it green to sort of match the drill press colour
Installed and wired up
light mounted
close up of the light head, which I'm rather pleased with
in action
it isn't super bright, but it's close enough that I don't think it'll matter much. It's certainly better than not having a light! Happy New Year!