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I just finished mounting my LEDs on my heatsink last night.

BTW I've heard some not great things about LEDsupply.com. No personal experience, just in PMs with people on various forums.

I went with RapidLED for mine.
 
Tamazula said:
I just finished mounting my LEDs on my heatsink last night.
BTW I've heard some not great things about LEDsupply.com. No personal experience, just in PMs with people on various forums.
I went with RapidLED for mine.

Interesting about the problems. Never had an issue myself, only problem on anything was a delay with Cutter.
The issue I had with both RapidLED and LEDsupply is that you have no idea what the bin code is,
so I ended up with Cutter for main CW+RB. Cheaper also.

Must be nice to have a nano, and not to have to do 140 LEDs.
Getting tedious.
 
Tamazula said:
It helps to have a full-on EE, DIY obsessed friend with a full workbench and lots of soldering experience. :)

Helps to be one as well. :)
Although I was never a lab tech, the skill those guys have puts me to shame.

My latest trick:
1) Put a pretty sizable solder blob on the LED pad. Work it around to cover the whole pad.
2) Put a tiny bit of solder on the wire, and make sure the wire itself is fairly hot.
3) Re-melt solder blob on LED pad, and while tip is still is on there, quickly push still-hot wire into solder.
Best if you align the tip with the wire, so it is along one side, then push wire in,
and bring tip up-and-over wire to other side.

Normal soldering techniques just do not work right with the pads sucking the heat out so fast,
and you do not want to let it get too hot and fry the LED.
 
Qwiv said:
what size iron you using. I would use a 90/95 watts and have the LEDs mounted already.
I only have a 70 watt. Big jump in price to hit that 95 watt range.
Although cheap compared to the mountain of LEDs. :)
I keep saying I will buy a thicker tip as well....

Not like it is really a big deal either way, just a bit tedious and annoying.
 
you are using flux right? :D

I wouldn't do the "big blob of solder" bit as reheating that might be an issue if it's pulling heat quicker than you can put it in. They can be a royal PITA to solder on a heat sink too, but doable with a 50W solder iron without too much difficulty.

Pre-tin your wires, put flux on the pad, flux on the wire (that has the solder on it, place wire end on pad, push solder on top, you should be able to feel when the solder melts, hold for a bit, then depending how sloppy your tinning was maybe add a bit more solder to make it work.
 
sfsuphysics said:
you are using flux right? :D

I wouldn't do the "big blob of solder" bit as reheating that might be an issue if it's pulling heat quicker than you can put it in. They can be a royal PITA to solder on a heat sink too, but doable with a 50W solder iron without too much difficulty.

Pre-tin your wires, put flux on the pad, flux on the wire (that has the solder on it, place wire end on pad, push solder on top, you should be able to feel when the solder melts, hold for a bit, then depending how sloppy your tinning was maybe add a bit more solder to make it work.

The reason for the big blob - only 2 hands. :)
Hand 1 = iron. Hand 2 = wire. Hand 3 - solder. Uh-oh.
Ok, just yanking your chain. Sure, you can anchor the wire with a clip or tape.
But really - the assembly line blob method is fast. And with 140 to do....
If I could duct-tape them, I probably would.

The solder blob melts pretty easily. The reason is that there is great thermal conductivity between
the iron and the solder, as the iron sinks down into the blob.
And you can even do it with a small iron, if you are fast, since it will melt before all the heat is pulled from the iron.

I am using rosin core solder, and have not really needed to add extra flux.

---

BTW: The real pain is DESOLDERING the wire from the glued-on LED pad when you make a mistake.
But that never happens. 8)
 
rygh said:
BTW: The real pain is DESOLDERING the wire from the glued-on LED pad when you make a mistake.
But that never happens. 8)

Never ;)

I used more solder on the LED today to reattach two wires broken loose while I fixed the heatsink to the wood frame. It worked much better. Glad to hear a ball of solder is not bad for the connection. Did not know, but it just worked for me today that way.

Today it is all together to then hang tomorrow, and by that adding wire to get reach from the closet where the drivers will mount. This is actinic string on.
P1020013-1.jpg
 
Just soldered my LEDs tonight. Had no problems with a 50 watt iron dialed to a little over 800 degrees F. It's far, far easier with a slightly wide tip instead of a pencil tip.

I soldered them attached to the heatsink and didn't find it to be too difficult... actually I experimented a bit with my hot air gun, using it from a distance to turn the entire heatsink warm (roughly 100-150 degrees) and that made the soldering even easier, but it was more trouble than it was worth. I did doublecheck the reflow characteristics before trying this, hehe.

Had an initial trial run using a 9V battery on a Meanwell and everything lit up beautifully on both circuits. Hooray.
 
Hey Yardartist:
Nice looking setup!

But a concern:
That looks like several meanwell supplies plugged into a singe relay on a reef angel box.
Might be a long term problem. Not sure the relay can handle the inrush current.
If you have spare relay ports, stagger them slightly. Even just a few seconds.
I think I even remember someone with a similar issue on the reef angel forum site.
 
Tamazula said:
Just soldered my LEDs tonight. Had no problems with a 50 watt iron dialed to a little over 800 degrees F. It's far, far easier with a slightly wide tip instead of a pencil tip.
Yeah, I really need to get a different tip I think.

Tamazula said:
... actually I experimented a bit with my hot air gun, using it from a distance to turn the entire heatsink warm (roughly 100-150 degrees) and that made the soldering even easier, but it was more trouble than it was worth. I did doublecheck the reflow characteristics before trying this, hehe.
Good info. I just received my replacement heat gun, but sounds like it is not worth it.
Also, with the huge heat sinks, not as viable anyway.


Tamazula said:
Had an initial trial run using a 9V battery on a Meanwell and everything lit up beautifully on both circuits. Hooray.
Great!
Pictures? (yes, I need to add some as well)
 
rygh said:
Hey Yardartist:
Nice looking setup!

But a concern:
That looks like several meanwell supplies plugged into a singe relay on a reef angel box.
Might be a long term problem. Not sure the relay can handle the inrush current.
If you have spare relay ports, stagger them slightly. Even just a few seconds.
I think I even remember someone with a similar issue on the reef angel forum site.

With two ports on the box I have two drivers in one and the third in the other. The current schedule. I will go look at the Reef Angel site to read up. Thanks.

two strands of 12 LED, 5 white 7 blue, on 12:00 off 6:00 with 30 minute ramp up and down from 0% to 50% on each end.
One strand of 1 UV 2 red 2 light blue 6 royal blue on 10:00 off 10:00 with same 30 minute ramp up for 0% to 50%.
 
rygh said:
yardartist said:
Dave found that a small scratch on the LED pads helped the solder seal to it better.
Interesting, I will try that.
I do solder leads on the LEDs before gluing them to the heat sink, which makes it easier as well.
Soldering afterward can be almost impossible for some vendors.

We had issues of large AWG vs the tiny pad. Massive thermal differences.
Also solder was high-purity silver stuff I use for in-vacuum PCB's and the sort it definitely does not solder easy but it's super clean at least! Had we gone el-cheapo style it probably would have been easier ;) But only the finest for Richard, only the finest...
 
houser said:
We had issues of large AWG vs the tiny pad.
Not sure what AWG you used, but a concern:
There is a big difference in expansion factor between wire/pad and substrate, and the
tops of the LEDs get fairly hot. Big heavy duty wire might tear off the pads long term.
Not a huge concern unless those wires are really thick though.
 
IMO it's best to use stranded wire because it's more flexible. I used 22 awg and also left a slight curve or S shape in each short run so that expansion and contraction has plenty of room and won't affect the pad itself.

Also don't underestimate those heat guns, you can heat up a huge piece of metal with one and keep it warm. I was working in a freezing cold garage and it still did the job.

Pictures... I have them on my camera but took a few on my phone. Here's one:

Work bench:

img08001.jpg



Testing the RB circuit:

img08011.jpg
 
Gotta love how cameras flail when it comes to accurate color representation of LEDs.
:)

Yes, I use 22 guage pre-tinned stranded as well.
I also just realized we had the same wire discussion on page 1/2 of this thread. In October.
Doh - sure is taking me a long time.
 
I need to secure 24 LED's to my heat sink. I would prefer not to tap and screw each one.
Have you guys tried any of the self adhesive heat sink pads?
 
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