Couple of noob questions

Hi all,
I've gotten into electronics thanks to a class I'm taking (only took
until grad school to find out that I enjoy this stuff :-)) I've just
built my first microcontroller project and am trying to get myself
outfitted to do electronics work at home. A couple of questions:

* What's the best way to solder to a DB-25 parallel port connector?
I've done it successfully, but made a horrible mess of things. I
started with some stranded 26ga (I think) wire and stripped off about
1/4" from the end, then put it in the little hold on the back of the
pin, got out the soldering iron, and made quite a mess. Is there a
good way to hold things in place for this operation?

* 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...

* 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.

Thanks for any advice!

Dan Lenski

dlenski@gmail.com wrote in news:1133834249.994844.113580
@f14g2000cwb.googlegroups.com:

*snip*

* What's the best way to solder to a DB-25 parallel port connector?
I've done it successfully, but made a horrible mess of things. I
started with some stranded 26ga (I think) wire and stripped off about
1/4" from the end, then put it in the little hold on the back of the
pin, got out the soldering iron, and made quite a mess. Is there a
good way to hold things in place for this operation?

Good heat transfer, a clean tip, and lots of practice. I usually go from
one direction to another, either right to left, left to right or middle
outwards. You'll mess a few of these up before you get it down.

*snip*

* 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.
*snip*

I don't know about the DC area /per say/, but there's lots of
mail/internet order places around. Radio Shack recently (last 5 years)
has focused mainy on consumer electronics, so mail/internet may wind up
being your best/only option.

Puckropper
--
www.uncreativelabs.net

Old computers are getting to be a lost art. Here at Uncreative Labs, we
still enjoy using the old computers. Sometimes we want to see how far a
particular system can go, other times we use a stock system to remind
ourselves of what we once had.

To email me directly, send a message to puckdropper (at) fastmail.fm

On Tue, 06 Dec 2005 03:04:40 +0000, Puckdropper wrote:

dlenski@gmail.com wrote in news:1133834249.994844.113580
@f14g2000cwb.googlegroups.com:

*snip*

* What's the best way to solder to a DB-25 parallel port connector?
I've done it successfully, but made a horrible mess of things. I
started with some stranded 26ga (I think) wire and stripped off about
1/4" from the end, then put it in the little hold on the back of the
pin, got out the soldering iron, and made quite a mess. Is there a
good way to hold things in place for this operation?

Good heat transfer, a clean tip, and lots of practice. I usually go from
one direction to another, either right to left, left to right or middle
outwards. You'll mess a few of these up before you get it down.

Thanks for the tips!

* 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.
*snip*

I don't know about the DC area /per say/, but there's lots of
mail/internet order places around. Radio Shack recently (last 5 years)
has focused mainy on consumer electronics, so mail/internet may wind up
being your best/only option.

Thanks, I've ordered a few things from Jameco so far. The trouble is that
I don't have a good "spare parts box" yet... so if I suddenly decide I
need a 74190 IC, I have to wait a few days or pinch 'em from the lab.
Perhaps I ought to buy a couple of those big component assortments from
Jameco...

Dan

On 5 Dec 2005 17:57:30 -0800, dlenski@gmail.com wrote:

Hi all,
I've gotten into electronics thanks to a class I'm taking (only took
until grad school to find out that I enjoy this stuff :-)) I've just
built my first microcontroller project and am trying to get myself
outfitted to do electronics work at home. A couple of questions:

* What's the best way to solder to a DB-25 parallel port connector?

Without solder. Look for the connectors that use crimp connections, like
these http://www.mpja.com/viewallpict.asp?dept=376&main=83 that crimp
onto a ribbon cable (commonly called IDC for Insulation Displacement
Connector).

Or the kind that crimps individual wires like these from Jameco
http://www.jameco.com/Jameco/catalogs/c254/P108.pdf. You'll need a
proper crimp tool, though. I like my ol' AMP Service Tool (p/n 696202-1)
for this.

I've done it successfully, but made a horrible mess of things. I
started with some stranded 26ga (I think) wire and stripped off about
1/4" from the end, then put it in the little hold on the back of the
pin, got out the soldering iron, and made quite a mess. Is there a
good way to hold things in place for this operation?

Get one of those alligator-clip jobbies commonly called a "third hand"
tool. A small, inexpensive bench vice is handy also; doesn't have to be
terribly large, since most of what you'll probably be working on is
relatively light weight.

* 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 prototype boards with "three holes per" are probably the quickest
and easiest for one-off items. Even perf board without solder pads will
work; just solder to the component leads.

The toner transfer method is probably the easiest for at-home etching
<http://www.pulsar.gs/PCB/a_Pages/4_Products/5b_Transfer_Paper/Transfer_paper.html>
but there are also lots of commercial sources for low quantity prototype
runs that aren't terribly expensive.

See the message <dluggk01kmu@enews1.newsguy.com> in the thread "Which is
the best hobby do-it-yourself method for making PCB's?" (actually, read
the whole thread).

* 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.

Mail order. Digikey. Or Jameco, Mouser, Newark, MPJA, AllElectronics,
....

--
Rich Webb Norfolk, VA

<dlenski@gmail.com> wrote in message
news:1133834249.994844.113580@f14g2000cwb.googlegr oups.com...

Hi all,
I've gotten into electronics thanks to a class I'm taking (only took
until grad school to find out that I enjoy this stuff :-)) I've just
built my first microcontroller project and am trying to get myself
outfitted to do electronics work at home. A couple of questions:

* What's the best way to solder to a DB-25 parallel port connector?
I've done it successfully, but made a horrible mess of things. I
started with some stranded 26ga (I think) wire and stripped off about
1/4" from the end, then put it in the little hold on the back of the
pin, got out the soldering iron, and made quite a mess. Is there a
good way to hold things in place for this operation?

I find the best way is to not solder them at all by using DB connectors
designed to use crimp-on pins. You strip the wire, crimp on the wire
and insert the pins into the DB connector shell in the correct hole.
You will need a crimp tool and extraction tool designed for the pins
you'll be using. You can use simple hand crimpers which cost $20 or a
crimp tool that holds the pin for you, crimps both the wire and
insulation at once, and are controlled so you can't over or under crimp
the pin for $100+. Two of the reasons I prefer the DB crimp connectors
are that there aren't any exposed wires on the back of the connector and
the shells can easily be re-used by simply extracting the pins.

If you must use solder DB connectors, there are a few things you will
need to make this a lot easier. First, you need a good soldering iron
with a small enough tip that you can easily contact just one pin at a
time. If you plan to do much electronics work you should invest in a
temperature controlled solder station with interchangeable tips.
Second, you'll need some type of vise to hold the connector so you can
use one hand to hold the iron and the other to hold the wire. Third,
you will want some small (1/16" or 3/32") heat shrink tubing to insulate
the pins after you solder them. You will want to use 22 to 24 AWG
stranded wire for DB connectors whether you use solder or crimp-on
connectors.

Now for technique. First, strip the insulation from the wire (1/8" or
so), tin the ends and slip a short piece of heat shrink on each wire.
Then fill the solder cups on each pin in the DB connectors you will be
connecting wires to with solder. Then heat the connector pins until the
solder re-melts and slowly insert the pre-tinned wire in being careful
to get all the wire strands in the pin cup. While holding the wire
steady, remove the soldering iron and allow the connection to cool
without moving it. Then slide the heat shrink tubing down the wire,
over the pin and apply heat to shrink it in place.

Good luck with electronics.

--
James T. White

dlenski@gmail.com wrote:

* What's the best way to solder to a DB-25 parallel port
connector?

The trick to doing this without needing three hands is to
tin both the wire and the solder cup first, then reflow the
solder.

Tin the wires. Unreel six inches or so of solder and bend it
so it sticks up vertically from your bench top. Now you can
hold the iron in one hand and the wire in the other while
you tin the wire.

Hold the connector in a small vise (Panavise or similar.)
Partially fill the solder cups with solder. Hold the wire
against the cup and touch the cup and the wire with the tip
of your soldering iron to reflow the solder. There should
be a tiny bit of solder on the tip to aid in heat transfer.

--
-- Steve

On Mon, 05 Dec 2005 17:57:30 -0800, dlenski wrote:
<soldering DB25s>

I bought some stuff from these folks:

http://www.winfordeng.com/products/cat_pbc.php

You can also buy those angle connectors directly from digikey, but you
then need to make a PCB to use them.

--
Regards,
Bob Monsen

The concept of fiction was nowhere in Mike's experience; there was
nothing on which it could rest, and Jubal's attempts to explain the
idea were so emotionally upsetting to Mike that Jill was afraid that
he was about to roll up into a ball and withdraw himself.

dlenski@gmail.com wrote:

Hi all,
I've gotten into electronics thanks to a class I'm taking (only took
until grad school to find out that I enjoy this stuff :-)) I've just
built my first microcontroller project and am trying to get myself
outfitted to do electronics work at home. A couple of questions:

* What's the best way to solder to a DB-25 parallel port connector?
I've done it successfully, but made a horrible mess of things. I
started with some stranded 26ga (I think) wire and stripped off about
1/4" from the end, then put it in the little hold on the back of the
pin, got out the soldering iron, and made quite a mess. Is there a
good way to hold things in place for this operation?

You need to 'tin' the stripped wire before placing it in the solder buckets
of the connector.

I'll bet that makes a *huge* difference.

Graham

On 2005-12-06, dlenski@gmail.com <dlenski@gmail.com> wrote:

Hi all,
I've gotten into electronics thanks to a class I'm taking (only took
until grad school to find out that I enjoy this stuff :-)) I've just
built my first microcontroller project and am trying to get myself
outfitted to do electronics work at home. A couple of questions:

* What's the best way to solder to a DB-25 parallel port connector?
I've done it successfully, but made a horrible mess of things. I
started with some stranded 26ga (I think) wire and stripped off about
1/4" from the end, then put it in the little hold on the back of the
pin, got out the soldering iron, and made quite a mess. Is there a
good way to hold things in place for this operation?

strip half an inch twist it, put some solder on it, trim it back to about 1/8"
or less and then solder that into the little pocket.

* 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...

I still use stripboard

* 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.

I don't know of any in that area, but I have found the yellow pages to
be helpful. "electronic component suppliers" is the category to look under.

Bye.
Jasen

Jasen Betts wrote:

strip half an inch twist it, put some solder on it, trim it back to about 1/8"
or less and then solder that into the little pocket.

Bye.
Jasen

Your method wastes time and materials. You need to learn how to do a
better job when you solder. Just strip it to 1/8" and tin the wire.
Remember to touch one side of the wire with the hot soldering iron and
apply the solder to the other side. Do not apply the solder directly to
the iron or you will burn away all the flux which will cause bad looking
solder joints.

As far as holding the connector, I like to plug it into a mating
connector mounted on a metal bracket, or clamp it gently in a drill
press vise. Small ones are under $10 in a lot of places. These are good
for holding the bare wires for tinning as long as you don't close the
jaws too tight.
--
?

Michael A. Terrell
Central Florida