DIY copper soldered led interference fit led-post with handtools only

Another thought.. why haven't I seen this around yet ....

You would loose the losses within the star and this will divide the heat over the heatsink faster.
Paste or grease will fill any void if you use a bleedhole.
Soldering the led can be done before mounting the post.
A key to turn the post can be made by making a cut in a strip of steel, overstressing the copper is the hardest part, don't make the thread in the aluminium to narrow.
You will need a cheap set of threadmaking tools and a vice, but you wont be depending on a lathe machinist for making a proper thermal connection.
And the aluminium sink would have to have a certain mininimum thickness, say 10-15mm to make the effort worthwhile ?

Find rod
Bore and thread sink
Thread rod
Dry fit rod and cut rod to size and file/Dremel slot for Led/key
Solder led and wires
Mount post with TIM
Done

Re: DIY copper soldered led interference fit led-post without lath

Sounds OK to me, have you tried it yet?

Re: DIY copper soldered led interference fit led-post without lath

Not yet, always pondering how to mount the led. This seems a practical approach and do-able with more then fair results.

Re: DIY copper soldered led interference fit led-post without lath

One thing to keep in mind is that the majority of power LED's have their contacts on the bottom now.

I had wanted to solder an XP-G onto the end of a stove bolt a few weeks ago, but the bolt was so large that it covered the cathode & anode pad and would have shorted them together. If you were to scrape the pads off, or cover them with high temperature non-conductive material it might work, but then you'd have no place to attach your power wires.

I've seen a lot of people using thermally-conductive but electrically-resistive double-sided tape. They fasten the LED to the post using the tape, then solder the wires to the very edges of the PCB that the emitter sits on.

Re: DIY copper soldered led interference fit led-post without lath

calipsoii said:

One thing to keep in mind is that the majority of power LED's have their contacts on the bottom now.

I had wanted to solder an XP-G onto the end of a stove bolt a few weeks ago, but the bolt was so large that it covered the cathode & anode pad and would have shorted them together. If you were to scrape the pads off, or cover them with high temperature non-conductive material it might work, but then you'd have no place to attach your power wires.

I've seen a lot of people using thermally-conductive but electrically-resistive double-sided tape. They fasten the LED to the post using the tape, then solder the wires to the very edges of the PCB that the emitter sits on.

Click to expand...

That is correct, but this is doable for SST-50 / SST-90 etc, the bigger leds. Smaller leds can best be left on a PCB IMHO.

This idea could work. I know that electrical cabinets for automation systems have copper screws (M10 or something) to mount the ground wire on. That saves you the hassle of finding a copper rod and hand threading it .

Re: DIY copper soldered led interference fit led-post without lath

This got me to searching and I found this...............http://www.apachesales.com/pc_produ...eproducts&utm_medium=search&utm_campaign=feed

Re: DIY copper soldered led interference fit led-post without lath

The led can be soldered to the copper rod, but is there any reason why you couldn't solder the rod to the aluminum, too? Forget the threads. Just use a straight copper bar. Drill the hole, put some solder inside it, apply heat to the parts (some 200+ degrees Celsius should be enough with the traditional Sn-Pb solder), insert the copper rod (excess solder will overflow) and let the parts cool. It should be pretty easy to do and the heat transfer between metals should be as good as it can be. The heat expansion coefficient of copper is slightly smaller than the coefficients of aluminum and solder, but with these kind of temperatures and small rod diameters, I don't believe it is a problem.

Haven't tried this of course. Just an idea.

Re: DIY copper soldered led interference fit led-post without lath

Aluminium is by its nature incredibly hard to solder to. The only way I know how is some interesting fluxes that I presume strip the native oxide layer off while you're soldering.

Another material would be a better choice if you were to go that method (make the heatsink out of copper as well).