Couple of noob questions

On Tue, 06 Dec 2005 20:28:41 +0000, noti wrote:

dlenski@gmail.com wrote:
....
* What's the best way to do home made PCB boards? Clearly breadboards
and wire wrapping will only take me so far :-) I've seen the toner
transfer method and a couple of others. What's the easiest one to get
started with? I have access to either laser jet or ink jet printers...

The best way is to stop screwing around with nasty ass chemicals which
are incredibly toxic and will give you crappy results. You think any
company would seriously do this stuff? Even for prototyping? For
prototyping if it has to be done in house its usually done with a
milling machine. Otherwise, you could just design PCBs on some CAD
software (Eagle for instance) and then send them out to a board house.
They don't charge that much. Why would you want to expose yourself to
those chemicals if you don't have to? What do you plan to do with them
once you've used them? Please don't tell me you are going to dump them
down the drain.

Good Grief! The only thing wrong with 2.95/quart FeCl3 is that you have
to use good etching techniques and practices. You make the stuff sound
like cyanide (which, BTW, is used routinely in industry). It's really
quite innocuous. When it doesn't etch copper good enough any more,
you can either recharge it with some acid, which probably _is_ fairly
hazardous to handle, or dump a bunch of "washing soda", sodium carbonate,
into it, and _then_ it's safe to pour down the drain, although I also
hear it makes some kind of muddy sludge, which might or might not flush
well.

If _that_ makes you paranoid, then decant the supernatant liquid through
a filter of some kind - a coffee filter would probably be fine, and just
toss the sludge into the trash. It's basically rock powder, which either
Spehro Pefhany or John Popelish has pointed out. Or maybe both. ;-)

But, depending on your budget, and how much screwing around you want to
do - it once took me all day to make one 6" x 9" board, not counting
having the artwork shot. It might be simpler to send out some kind of
artwork - I hear that there are electronic CAD programs that will output
Gerber files, and there are board houses that can make you a board for,
like $50.00. I'm confident someone will clarify that, if I'm misinformed
about pricing. :-)

Good Luck!
Rich

On Tue, 06 Dec 2005 20:28:41 +0000, noti wrote:

dlenski@gmail.com wrote:

* Are there any stores in the DC area that sell electronics components?
The local Radio Shack is terrible and I feel guilty taking a diode or
two from work.

You feel guilty about taking a part from work that costs a couple cents,
but not playing with nasty chemicals which you have no good way to
dispose of? Sheesh, I take pens from work which cost more than diodes
inadvertantly all the time. I can't imagine they'll miss it.

These arent related (taking a part vis-a-vis using chemicals).

But they _do_ miss the parts. I know, I've been there, done that. But
there's a trick. You find the guy who's responsible for the parts, and
_ask_ him. "How can I check out parts for home projects?" They might
just say, "help yourself", they might say, "We can sell them to you at
our cost", they might say, "Welcome to the Future" - one doesn't know
until one finds out, does one? ;-)

Have Fun!
Rich

On Wed, 07 Dec 2005 02:14:10 +0000, Dan Lenski wrote:

Thanks for all the advice, everyone!

I had been hesitant to try Veroboard because it seems expensive and I know
I'll make lots of mistakes. Today I practiced point-to-point soldering
and was awful at it, so I think I need to use some method that will
require me to not solder little wires to little leads! Today I found this
site with some amazingly cheap Veroboard-type stuff:

http://www.elexp.com/pro_pb16.htm : Veroboard $1.65
http://www.elexp.com/pro_pb19.htm : DIP prototyping board $0.95

Thought I'd pass those links along... about 5x cheaper than anything I'd
seen before!! They also sell kits of capacitors, resistors, ICs, etc.
that seem quite well priced.

For what it's worth, I recommend against boards with long strips.
Admittedly, it's been a few years since I've used "perfboard" (that's
what we call it in Leftpondia, or "vectorbord", yes, that's "bord",
it's a trademark. But my favoritest of all is the kind with ground
plane on one side, actually a grid, with clearance for each and every
hole, and a pad-per-hole on the other side. I just don't trust my
skills at chiseling away at a copper band on a prototyping board. And
it's remarkably easy to wire it point-to-point with #30 wire-wrap wire,
especially if you have a good stripper: I ground down the rivet and
took the stripper blade off a WSU-30M once:
http://www.mouser.com/catalog/624/1599.pdf
and clamped it in an X-acto knife handle:
http://www.reuels.com/reuels/page173.html
so I could daisy-chain wire-wrap wire by just sliding the whole
insulation down the wire, stripping about 3/16" for each connection.

Good Luck!
Rich

On Wed, 07 Dec 2005 09:16:35 -0800, dlenski@gmail.com wrote:

Bob Myers wrote:
No, stick with it - sooner or later, you're going to pretty much HAVE to
be able to "solder little wires to little leads," so you might as well
practice it now. You'll catch on. A couple of tips:

Thanks for the tips, Bob. I think my problem may have been that I was
using a plastic perfboard with no copper cladding. Whenever a drop of
solder touched the perfboard, it would cling to the nearby metal. This
made a mess when trying to solder wires close to the surface of the board.

Is it correct that solder will NOT adhere to a plastic surface?

Not "adhere", but it will melt itself into plastic.

What kind of plastic perfboard are you using? Frankly, it's the first time
I've ever heard of any - they're either phenolic or fiberglass.

I had a much easier time soldering two wires which weren't right next to
the metal surface.

Which metal surface is this?

I guess the board with copper pads is easier to work
with because the solder will adhere to it.

And, as I've said, see if you can find one with individual pads - you
can solder the parts in place (to the pads), and _then_ string your
wires.

Good Luck!
Rich

On Wed, 07 Dec 2005 19:05:23 +0000, Bob Myers wrote:

dlenski@gmail.com> wrote in message

Is it correct that solder will NOT adhere to a plastic surface?

In general, that's correct - it will, of couse, melt many plastics while
hot, and can really make a mess of things.

Not all metals are solderable, either; copper conductors obviously are,
including wiring which has been "tinned" (coated with a thin covering of
solder or some other metal/alloy, which both improves the solderability as
well as protecting the bare copper surface from oxidation). Aluminum, on
the other hand, is not easily solderable with standard tin/lead solders -
you can get it hot enough, of course, but regular solder will just bead up
on an aluminum surface and refuse to "stick."

I've heard that there _is_ "solder" that will "stick" to aluminum, but
I've also heard that it's such a PITA to try to get it to operate properly
that it's worth it to just take your aluminum parts to a TIG shop. :-)

Have Fun!
Rich

Bob Myers wrote:

"Dan Lenski" <dlenski@gmail.com> wrote in message
news:pan.2005.12.07.02.09.37.308409@gmail.com...

Thanks for all the advice, everyone!

This post has some great soldering advice that I plan on studying in
much more detail. My soldering consists of fairly simple hobby-type
stuff, but still I'd like to be able to make those perfect little
"hershey's kiss" type solder-dots. Now, I can solder small things
together without shorting two things close together, but I've *never*
figured out the technique to make those perfect-looking little pointy dots.
Any specific advice for that? I generally use rosin-core 60/40 RS
solder, btw. is that less-than-recommended for the level of 'perfection'
i'm desiring, or is it all in the solderer's control? remember, i'm not
a pro nor do i play one on tv- just an occasional hobbyist but I *am* a
perfectionist, and ugly solder joints just bug me.
TIA
karinne

k wallace wrote:

Bob Myers wrote:

"Dan Lenski" <dlenski@gmail.com> wrote in message
news:pan.2005.12.07.02.09.37.308409@gmail.com...

Thanks for all the advice, everyone!


This post has some great soldering advice that I plan on studying in
much more detail. My soldering consists of fairly simple hobby-type
stuff, but still I'd like to be able to make those perfect little
"hershey's kiss" type solder-dots. Now, I can solder small things
together without shorting two things close together, but I've *never*
figured out the technique to make those perfect-looking little pointy dots.
Any specific advice for that? I generally use rosin-core 60/40 RS
solder, btw. is that less-than-recommended for the level of 'perfection'
i'm desiring, or is it all in the solderer's control? remember, i'm not
a pro nor do i play one on tv- just an occasional hobbyist but I *am* a
perfectionist, and ugly solder joints just bug me.
TIA
karinne

Solder joints should have the Hershey Kiss look, only if there is a
lead sticking up out of the joint, with the solder wetting up the wire
and pad below it. A solder dot on a pad should be smooth a shiny on
top, more like an M&M or a small donut. Anything rough or with points
indicates either oxidation on the solder (iron too hot so it burns all
the flux off or there was not enough flux to cover the solder and keep
it from being exposed to oxygen before it solidified) or soldering
iron too cold to melt the solder fully. A good alloy like 63% tin,
37% lead or 62% tin, 36% lead, 2% silver also flows a bit better than
60%tin, 40%lead, or (shudder) 50% tin, 50% lead, or (cringe) 40% tin,
60% lead.

Don't dab with the iron. This just helps oxygen get mixed with the
molten metal, creating dross on it. Apply heat to the pad and wire to
be joined, perhaps with a touch of solder between iron and metal, to
form a thermally conductive path. Then sweep the end of the solder
around the lead to spread the flux to wet everything that needs to be
coated with solder. This sounds like a lot of solder, but if you are
using something like .02 inch diameter, or .032 inch, it need not be
very much.

Finish by sliding the iron up the lead, so the excess follows the iron
up. Then, when you trim the lead, you also trim the excess solder
off. You should end up with a tiny Hershey's Kiss with the top
trimmed off (ideally, with flush cutters for a flat, non snaggy tip).

Never use acid core solder on electronics, because the flux residue is
both corrosive and conductive.

On Fri, 09 Dec 2005 18:04:23 -0800, k wallace wrote:

Bob Myers wrote:
"Dan Lenski" <dlenski@gmail.com> wrote in message

Thanks for all the advice, everyone!

This post has some great soldering advice that I plan on studying in
much more detail. My soldering consists of fairly simple hobby-type
stuff, but still I'd like to be able to make those perfect little
"hershey's kiss" type solder-dots.

Just in hopes of keeping you from going down the wrong track here,
a "hershey's kiss" solder blob means you've used at least three times
as much solder as you should have. It should be a smooth fillet,
that just blends in to both the copper dot on the board (which should
have already been tinned) and the component lead. For SMT, a fillet
joint with minimal solder is almost de rigeur, IIUC. (I think they
call that "sweat-soldering" - the solder wicks up between the pad
and the chip by capillary action.) What you want is good wetting.

Now, I can solder small things
together without shorting two things close together, but I've *never*
figured out the technique to make those perfect-looking little pointy dots.
Any specific advice for that? I generally use rosin-core 60/40 RS
solder, btw. is that less-than-recommended for the level of 'perfection'
i'm desiring, or is it all in the solderer's control? remember, i'm not
a pro nor do i play one on tv- just an occasional hobbyist but I *am* a
perfectionist, and ugly solder joints just bug me.

Practice, practice, practice. :-)

Here ya go:
http://images.google.com/images?q=%2...=Search+Images

Have Fun!
Rich

On Fri, 09 Dec 2005 22:10:41 -0500, John Popelish wrote:

k wallace wrote:
Bob Myers wrote:

"Dan Lenski" <dlenski@gmail.com> wrote in message
news:pan.2005.12.07.02.09.37.308409@gmail.com...

Thanks for all the advice, everyone!


This post has some great soldering advice that I plan on studying in
much more detail. My soldering consists of fairly simple hobby-type
stuff, but still I'd like to be able to make those perfect little
"hershey's kiss" type solder-dots. Now, I can solder small things
together without shorting two things close together, but I've *never*
figured out the technique to make those perfect-looking little pointy dots.
Any specific advice for that? I generally use rosin-core 60/40 RS
solder, btw. is that less-than-recommended for the level of 'perfection'
i'm desiring, or is it all in the solderer's control? remember, i'm not
a pro nor do i play one on tv- just an occasional hobbyist but I *am* a
perfectionist, and ugly solder joints just bug me.
TIA
karinne

Solder joints should have the Hershey Kiss look, only if there is a
lead sticking up out of the joint, with the solder wetting up the wire
and pad below it. A solder dot on a pad should be smooth a shiny on
top, more like an M&M or a small donut.

NO! NO! NO!!!

There should be no blob. It should make a smooth transition - at the
edge of the solder fillet, it should just feather into whatever it's
supposed to be bonding.

If you have a lump like a Hershey Kiss, or an M&M, or a "small donut",
you're doing everything exactly wrong - iron's too cold, too much
solder, didn't heat up the component lead or the pad enough to get
good wetting. Solder is _NOT_ hot-melt glue.

I looked up "Good Solder Joints" (with the quotes) on Google images -
http://images.google.com/images?q=%2...=Search+Images

lemme go see if I can go pick a really good example...
http://www.antex.co.uk/images/betterfig5.jpg

Here's an example of a very bad solder joint:
http://aplsweb.com/Wiper-Fix/Wiper10.jpg

This is a very long link - please do mind the wrap:
http://images.google.com/imgres?imgu...3Doff%26sa%3DG

Have Fun!
Rich