On 4/9/21 11:22 PM, Bert Put wrote:
test?
Many, many years ago on a distant shore
Men did gather secretly beyond a hidden door
What's more appropriate for soldering than heavy metal and songs about
hell? It's literally lead, and it's literally hot enough to melt, and
there's even noxious fumes. Soldering is metal af. :)
Got a technique pretty much down for making dip legs on pcbs out of
plain gold plated brass jewelry wire.
https://photos.app.goo.gl/mQnsaH5LVoQW2RdJ6
Stick a dip-28 machined round socket in a breadboard.
Cover the top with a piece of painters tape. I'm using green Frog tape,
but anything like masking tape or blue painters tape will work the same.
Set the pcb on top of that.
Poke the brass wire down through the top of the pcb in one corner via,
punch through the tape, into the socket, and bottom it out in the socket.
Snip the wire flush with the top of the pcb.
Repeat for the opposite corner.
Add flux and solder those two legs. You only need to touch the heat to
the top, The flux will tak ethe solder down into the via and the tape
will keep the solder from going down into the socket. 2 or 3 seconds is
generally plenty.
Then repeat just the poke & cut steps for all other legs.
Then solder all legs.
The wire you want is 26 gauge gold-filled brass, half-hard.
"gold filled" is like gold plated but way more gold than we actually
need, but no one seems to sell merely gold plated wire, just bare brass
or gold-filled.
26 gauge is thin enough to fit into machined round sockets and not even
theoretically harm any sockets by stretching them out like ordinary
square pins do, yet strong enough to inserted into connectors without
bending. Prices vary pretty widely for the same product, so you should
shop around...
These are some that I actually purchased and tried and they work well:
This is probably the most economical I've found so far:
https://www.wirejewelry.com/round-red-brass-wire/26_Gauge_Round_Half_Hard_Red_Brass_Wire-14549-901.html
https://www.amazon.com/gp/product/B07HCMYWGN?psc=1
https://www.ebay.com/itm/Red-Brass-Wire-Round-Half-Round-Square-14-16-18-20-21-22-24-26-28-Gauge/123161530578?var=423571461737
https://www.ebay.com/itm/26ga-Gold-plated-copper-round-wire-4mm-015-create-wire-wrapped-jewelry-pw023/203158831071
This one (below) does NOT work well, but only because it's thinner than
26 gauge despite saying 26 gauge. Perhaps 24 gauge from the same
supplier would be perfect. Even this does work, just the legs are a bit
thin and weak. They still do manage to insert into even fairly stiff
sockets without folding, so really, you could use this just fine. And
the thin/weakness of the wire does have a benefit that when you bend the
legs accidentally from handling the finished object, you can just bend
them back and they don't break off.
https://www.amazon.com/gp/product/B07S9JFK2V
This one works but is a bit softer than ideal. It does say copper not
brass, so it makes sense. However, "dat price tho"... Stiffer brass is
better, but this does actually work. It's just a little more delicate
about punching through the painters tape. The legs insert into sockets
just fine.
https://www.ebay.com/itm/26ga-Gold-plated-copper-round-wire-4mm-015-create-wire-wrapped-jewelry-pw023/203158831071
And you want to avoid any that say "tarnish resistant" or "gold color",
because they will actually be aluminum wire with an enamel coating.
Example of what at avoid:
https://www.amazon.com/dp/B077ZP7H4C
Exmple of what to get (I didn't actually buy this one, it's just an
example that meets the criteria):
https://www.amazon.com/dp/B06ZZ83F5N
The advantage? The point of all this? Actual micro-pins from MillMax or
Keystone are around $0.10 per pin in small quantities and don't go down
very much in larger quantities. Punched sheet leadframe pins from
TE-Connectivity are also about $0.10 per pin, and those are only tin
plated not gold.
This method uses under 6.0mm of wire per pin (I measured 5.88mm average
over several pins). You can get 15,000mm of gold plated wire for $3 plus
$3.50 shipping from the ebay one above (49feet $2.95) That's 2,500 legs
for $0.0026 per leg, or $0.07 for an entire 28-pin pcb.
And the time/care/effort needed to do the job is actually about the same
for all 3 options.
Hey gold & brass... more heavy metal.
(The first two lines in this email are the first two lines in the most
ridiculously over the top caricature of a metal tune I ever heard. So is
the album art. Metal Church by Metal Church.)
This concludes this test of the m100 list broadcast system.
--
bkw
