Having had time for a quick play around with some Nichia 219 92 CRI 4500k LEDs from illumination supply I have decided they are the best tint out there and will probably stay at the top for quite a long time.
A while back, just before XM-Ls hit the scene, I used to really admire the triple XP-G drop-ins out there, especially the ones made at home with what was on hand. However, as XM-Ls came out, the idea of triple XP-G stayed just as innovative and cool (as did the look of the optics) but the practicality/ease to make/cost to benefit ratio just meant they didn't seem worth the effort anymore. An XM-L could do almost the same output with more throw and much easier assembly for much less $$$.
Anyway, now these Nichia 219s are out I suddenly have the urge to make a good triple with Carlco flood optics and a solid copper slug for great heat dissipation. The fact that it would have the potential to be a handheld 700 lumen 92 CRI 4500k man-made sun, running from a single 18650, has finally persuaded me to look into the possibility of actually making it.
I can get the driver, I can get the LEDs, I can get the optics, I can get the host and I think I can figure out the wiring without burning myself.. But my problem is; where can I find the heatsink/copper slug which will fit all of these together into the most awesome drop-in ever conceived of by mankind so far?
Thanks, I think that was dorpmuller in 'Rolled my own triple XP-G'. Unfortunately I don't know where I could find that exact part or what dimensions to look for (maybe I should just measure inside the head of my L2P).
It didn't look just like a tube, but had the flat part at the end to seat the LEDs on too if I remember correctly. I'd also need to work out exactly the dimensions to leave it length wise to have the LEDs seated at the right height for the optics.
I suppose it's just a case of working out the dimensions etc and going hunting in DIY stores for copper parts of the right dimensions?
EDIT: Thanks yeah that's the one, I'm just not sure what exactly I should be looking for to find a part as well suited as that. Also, I wouldn't look forward to filing down a brass pill to just the bottom half, I would have to do it by hand.. I probably would do if it was the only option though.
I've been playing around with copper plates lately and I have found something interesting.
You dont need a big thick slug. A 1mm copper plate where the stars are fixed will lead heat away to the body of a flashlight so fast you cannot tell if there is a difference. I have tried measuring it with a thermometer and a stopwatch but time the difference is so little that a +20°C temperature rise on any given place on the torch is less than 1 second.
Just fyi I am fully aware that there is a big theoretical difference but I have found the following is more important.
Making the surfaces mate up. I use a 600 grit emery cloth held flat on a table and just move the star around in varying patterns until it is completely flat. Takes 2 minutes.
Same procedure for the copper plate. Takes 5 minutes since that is bigger in my host than the star.
Then I use a thermal compound spread thin and pressed down hard with first the copper to the body and then the star to the copper.
That is far more important than a big copper slug.
Just take your empty host with you to the hardware store and do some test fitting. I think I remember him saying it was a 1/2" bushing and he had to add a layer of copper foil to the outside for a snug fit inside his L2 host.
Go to your local plumbing shop with the enpty host. Get a copper end cap that is the closest to the right fit. If there is none that is really close, get a size that will fit in and also get a larger size that you can cut for a sleeve. Also check the copper pipe for the right size. Fill the empty pill with solder. Fill it flush, use the copper end for the led and the solder end for the driver end. Just be inventive when looking for stuff at your hardware. If all else fails, see if you have a local shop that carries any aluminum rod that they would cut to length. I do it locally and they are not expensive. Make sure the "pill" you make is tight in the light. The tighter it is, the better it will allow heat to transfer out of ther pill. Try to make a fit where you do not need any thermal compound. Metal to metal is 50 times better than compound. If the mating parts are smooth and round and tight fit, you will have a good heat transfer to the body/head of the light.
Aluminum vs copper - copper heats faster, aluminum heats slower, but the difference is really not that much unless you are pushing the LED at max power constantly. Good metal to metal contact is the best thing you can do for heat transfer.
What I've done in the past to fill them is cut up a bunch of couplings and drop those in there and then seal it in with solder. Would filling it with just solder work better?
What sort of size do you need? I have some copper of various sizes about, mainly coated and in bars but if you can work it I'll send you some. I like this idea, interested how it turns out.
I think I'm looking for one of those copper couplers around 22mm diameter and 20-25mm height? With thick-ish walls if possible but not essential and then a round flat circle of copper (20-22mm diameter again to fit nicely on top) as a cap. Unless I use a copper end cap of the same size to begin with? Then maybe I wouldn't need the extra copper circle, but I'm no plumbing expert so I'm not all that familiar with the different parts.
I would prefer a solution which wouldn't leave me with having to manually file down a brass pill to use as a base for the driver (as dorpmuller did), but then would need some other way of fixing the driver in place. Perhaps I could thermally pot/glue it into the right position then connect the negative contact on it to the copper directly, but that would leave little margin of error as the glue would set and if it didn't work I'd be screwed.. So I probably wouldn't risk that tbh, filing may be the way to go.
Im not sure if anything I have will be of any use then as mine is electrical bus-bar, nothing plumbing like. I'll get a pic up, it's simply solid bar but I can roughly cut circles with a hole cutter, tho then it also has a 8mm (iirc) hole in the centre. My hole cutters are standards electrical fittings size but may be close enough to file, I'll check dimensions when I'm home
