LED and PCBs

I've used ExpressPCB where you layout your printed circuit on on your
computer (easy to use free software download) send it to them over the
internet, and for $63 get three two sided circuit boards with plated thru
holes. I've had and continue to have excellent service.
Stu Fields

From:
Subject: More LED's - Again
Date: Sunday, March 12, 2006 2:02 AM

To All:

The steady decline in the cost of ultra-bright green LED's (now about
two-bits each for a 100-piece baggie) has generated renewed interest in
the bug-eyed LED nav lights I described on this Newsgroup a couple of
years ago.

Unfortunately, that renewed interest has lead to some renewed problems,
one having to do with the lay-out of the circuit board, the other with
its fabrication. But the most serious problem has to do with the fact
that ham radio operators learn to solder shortly after birth, or even
before... according to some. Along with the ability to solder is the
companion knowledge of how to make a circuit board out of a bit of
substrate and a piece of string about... that long. But the main
stumbling block for non-hams appears to be how to make all those
teenie-tiny holes in the circuit board.

MAKING HOLES

It's pretty easy. You need a tiny drill -- somewhere between #70 and
#75. Then you need to spin it about 12,000 rpm. And you need to keep
it perfectly vertical as you make the hole.

The drill bits are no problem. Harbor Freight will sell you a
selection of solid carbide bits suitable for the task; simply pick a
size to suit the components you're using, such as the wire legs of an
LED or quarter-watt resister.

A Dremel tool (or similar) is the handiest means of chucking the tiny
drill, most of which have a shank diameter of 1/8".

To hold it perfectly vertical you don't 'hold' it at all -- you make up
a 90 degree bracket and clamp, wire or glue the tool to the vertical
leg. On the horizontal leg you drill a 1/4" hole to accept a bolt
which you then chuck into your DRILL PRESS. There's a few picky-bits
to this method, such as using a bracket that is a true 90, and thick
enough so as not to deflect as you run the quill of your drill press up
& down. You need some method of preventing the quill from rotating of
course -- I use a simple wedge between the quill pulley and the frame
of the drill press head (big, old Craftsman floor model. Your mileage
may vary...) To keep from ruining the chuck in your drill press (which
was not designed to grab hold of threaded bolts) you put a barrel-nut
on the bolt.

Deal with all the tricky bits and the result is a shake-free,
carbide-tipped hole-maker that will give you a life-time of accurate
service (and already has, in my case... I used it to make the boards
for my first computer back in the mid-70's).

ELEVATION vs AZIMUTH

Azimuth is relative to the horizontal. Elevation means over-head. In
laying out the circuit board, asimuth is taken care of by orienting the
legs of the LED's. Since the LED's have an average viewing angle of 25
degrees, to provide adequate coverage the azimuth angle starts at 10
degrees and progresses in 20 degree increments. Of course, when you're
trying to provide full coverage across a segment of a sphere, your
LED's must be accurately oriented in TWO dimensions.

The key point here is that I chose to build the aximuth angle into the
circuit board.

The elevation angle is bent into the legs of the LED's using a simple
form-block, accurately printed via DeltaCAD, glued to a bit of plywood
and sanded to the line. To keep things simple, I abandoned the
variable height arrangement as described in my original post, other
than allowing a bit of overlap between one row of LED's to the next so
as to keep down the circuit board, which comes out about two by two
inches.

As a further simplification, I eliminated the left vs right bending
angles used in my original (2002) lights. Now all of the LED's get the
same set of bends relative to their positive lead. To accommodate the
change from left- to right-facing, I re-drew the circuit board.

MAKING THE CIRCUIT BOARD

The Old Fashioned Way was to start with a drawing then go to litho
film, then to a fine-meshed silk screen. Once you had the silk screen
you could whip out a hundred circuit boards in an afternoon... after
spending a month to arrive at that point.

Nowadays I simply print the circuit board mask onto cheap
glossy-finished color photo paper using a monochrome laser printer.
Here's why it works:

Laser printer media is a finely divided thermo-plastic -- a powder so
fine it is attracted to the electrostatic charge created by the laser.
The thermo-plastic material is transferred to the paper by heat.

This lends itself to making circuit boards because once the
thermo-plastic material has been transferred to the paper, it may be
RE-TRANSFERRED to the clean copper surface of a blank circuit board by
the application of ADDITIIONAL heat. In effect, you literally iron-on
the mask, solidly gluing the paper to the circuit board.

Now the trick is to get rid of the paper, which I'll get to in a
minute. But before I do, you should know that while using plain paper
is possible, the resulting transfer will show a lot of voids; plain
paper simply isn't a very good substrait for the thermo-plastic
material. But cheap color copier paper is. Color copier paper is
typically coated, giving it a denser, more uniform surface than regular
#20 bond. That slicker surface attracts a more uniform layer of the
thermo-plastic material; you end up with a dense, dark, void-free
pattern.

But it's gotta be CHEAP color copier paper because you want the stuff
to dissolve in warm, soapy water. High quality color copier paper is
some very tough stuff; it doesn't like to come apart. But the paper
HAS to come apart if we want to leave ONLY the thermo-plastic material
bonded to our circuit board. So use the cheap stuff. And soak it in
warm soapy water. Then scrub it with a tooth brush or whatever -- get
ALL of the paper off of the thermo-plastic.

Now you can etch the board in the usual way. And having etched it, you
gotta drill those zillion holes. Once etched & drilled, remove the
thermo-plastic, which you can do with MEK or other kidney-killer
solvent and a bit of steel wool.

The result is a bright copper circuit board, ready to accept components
and easy to solder. Once things are soldered and checked and and all
the errors corrected, give the thing a coating of clear finger-nail
polish (!) and you're all done -- a super bright nav light that will
never burn out (at least, not in your life time) that draws about a
quarter of an amp, meaning the wiring can be slightly smaller than a
starter cable.

-R.S.Hoover
-(KA6HZF)

PS -- Yes, you may have a copy of the circuit boards, if you wish. But
you could probably do better yourself -- except for the stern-light,
they're just rectangular 5x9 arrays. I don't have a web site and I
already get more email than I want so I'll try to find somewhere to
hang them. When I do, I post the information here... for all 385
subscribers of r.a.h. to read :-)

Stuart & Kathryn Fields wrote:
I've used ExpressPCB where you layout your printed circuit on on your
computer (easy to use free software download) send it to them over the
internet, and for $63 get three two sided circuit boards with plated thru
holes.
------------------------------------------------------------------------------------

For comparison, All Electronics (www.allelectronics.com) will sell you
a 6x12" piece of copper clad circuit board for five bucks. That's
enough to do a dozen nav lights. It's single-sided but that's all that
is needed for such a simple circuit.

They will also sell you the etchant ($4). And Tinnit (if you wanna use
it).

Bottom Line: If you spend more than a buck per board you simply don't
understand the motivation behind Flying on the Cheap, which is the fact
that the median income in the United States is less than thirty grand a
year.

-R.S.Hoover

wrote:
Stuart & Kathryn Fields wrote:
I've used ExpressPCB where you layout your printed circuit on on your
computer (easy to use free software download) send it to them over the
internet, and for $63 get three two sided circuit boards with plated thru
holes.
------------------------------------------------------------------------------------

For comparison, All Electronics (www.allelectronics.com) will sell you
a 6x12" piece of copper clad circuit board for five bucks. That's
enough to do a dozen nav lights. It's single-sided but that's all that
is needed for such a simple circuit.

They will also sell you the etchant ($4). And Tinnit (if you wanna use
it).

Bottom Line: If you spend more than a buck per board you simply don't
understand the motivation behind Flying on the Cheap, which is the fact
that the median income in the United States is less than thirty grand a
year.

-R.S.Hoover


The parts for making boards are cheap. It is the time and effort that
is not cheap. $20 for a high quality professionally made board is not
bad, especially for double-sided and plated through holes. I almost
considered using ExpressPCB but I made my own boards only because it
was fun and educational, not because it was cheaper.

On 13 Mar 2006 10:07:48 -0800, wrote:


Stuart & Kathryn Fields wrote:
I've used ExpressPCB where you layout your printed circuit on on your
computer (easy to use free software download) send it to them over the
internet, and for $63 get three two sided circuit boards with plated thru
holes.
------------------------------------------------------------------------------------

For comparison, All Electronics (www.allelectronics.com) will sell you
a 6x12" piece of copper clad circuit board for five bucks. That's
enough to do a dozen nav lights. It's single-sided but that's all that
is needed for such a simple circuit.

They will also sell you the etchant ($4). And Tinnit (if you wanna use
it).

Bottom Line: If you spend more than a buck per board you simply don't
understand the motivation behind Flying on the Cheap, which is the fact
that the median income in the United States is less than thirty grand a
year.

Yah Bob, but Median is not nearly as meaningful as average and I'll
bet average is below median. Then again it depends on how they
calculate median. Is it against individual incomes, or do they place
incomes into groups. The US is one of the few places that uses median
while most of the world uses average.

At any rate, on the lights, how about using a plastic ball cut in
half. Just drill the holes and tie the leads together on the back side
and then pot it with epoxy or resin. You don't even need the circuit
board.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

-R.S.Hoover

Yah Roger... But is that average figured with or without Bill Gates in
the pool?
Without him I'm above average...
With him I'm out in the median, picking up beer cans for the deposit...

R.S. Hoover... Well, it may be true that hams are genetically encoded
to be able to solder... OTOH I've seen some ham solder jobs that raise
questions of genetic damage...

denny
k8do, and a bunch of other initials

On 14 Mar 2006 10:32:22 -0800, "Denny" wrote:

Yah Roger... But is that average figured with or without Bill Gates in
the pool?
Without him I'm above average...
With him I'm out in the median, picking up beer cans for the deposit...

R.S. Hoover... Well, it may be true that hams are genetically encoded
to be able to solder... OTOH I've seen some ham solder jobs that raise
questions of genetic damage...

Been out in my shop again, huh? I thought I had all those projects
hidden.

Just finished redoing the leading edge of the one elevator
shell...again!. Looks pretty good this time. Now I need to figure out
how to set up a small router to cut out the hinge access points so
they look good. Sand and fill, sand and fill, sand and fill, fill and
sand. (I like to change the routine and add a little variety at
times.)

Today was expensive. 250 Gig WD hard drive failed. Warranty failed
two weeks ago. Display failed on my Kenwood TM-V7A mobile rig. Free
replacement if I purchased it between Jan 1, 2000 and Jan 1, 2006. I
purchased it about the end of May 1999. $160 just for the display but
that does include shipping six bucks for shipping.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

denny
k8do, and a bunch of other initials

"Roger" wrote

Just finished redoing the leading edge of the one elevator
shell...again!. Looks pretty good this time. Now I need to figure out
how to set up a small router to cut out the hinge access points so
they look good.

I would use a jig, and a router bit to follow the jig. Make a big letter
"O", of whatever size and shape you need, tape it to the surface, and let
the non cutting surface of the bit follow around the inside of the template,
using rotation to force it to the template. I hope this is clear enough.
--
Jim in NC

On Wed, 15 Mar 2006 17:33:17 -0500, "Morgans"
wrote:


"Roger" wrote

Just finished redoing the leading edge of the one elevator
shell...again!. Looks pretty good this time. Now I need to figure out
how to set up a small router to cut out the hinge access points so
they look good.

I would use a jig, and a router bit to follow the jig. Make a big letter
"O", of whatever size and shape you need, tape it to the surface, and let
the non cutting surface of the bit follow around the inside of the template,
using rotation to force it to the template. I hope this is clear enough.

That's pretty much what I've been thinking, but the leading edge
curves down and I having come up with a form to follow the edge.
My big router, which is way too big for this job has some bits that
have ball bearings on the shanks for roll along the guide.
I'd like to come up with something like that on a 1/4" bit and I have
some aluminum channel that I could probably form to fit the shape of
the elevator skin. I'd use 1" angle for the back of the cut and run
the angle full length of the skin which would make the cuts uniform.
OTOH it takes a steady hand even with a guide. :-)) It that bit,
bites it can make it through the guides and half way across the shell
in an instant. Then I'd be rebuilding more than the leading edge.
No, I wouldn't. that'd be the point where I called New Glasair and
ordered a new set of elevator skins.

Thanks,

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

On Wed, 15 Mar 2006 01:44:29 -0500, Roger
wrote:

On 14 Mar 2006 10:32:22 -0800, "Denny" wrote:

Yah Roger... But is that average figured with or without Bill Gates in
the pool?
Without him I'm above average...
With him I'm out in the median, picking up beer cans for the deposit...

This post never turned up on my server so I'm kinda answering it out
of order.

Even though ol' Bill is worth 40 some Billion, his annual income is
probably no more than a paltry few hundred million. Divide that by
the number of tax payers and for the average he isn't going to change
it more than a dollar or two.

Median leaves a lot to the imagination as to how they figure it. Is
it on every return based on value. (Every return with a value of say
$20,000 is lumped together and the total only counts as one), or do
they count it in brackets in increments of a $1000, $2000, $10,000.
Each bracket would only count as one. More than likely they go in
steps of a million or more up in that rarified atmosphere.

As an exaggeration they could have one bracket of zero to 20,000, one
of 20 to 30 thousand, and one of everything greater than 30 thousand.
That would make the median the 20 to 30 thousand range. or zero to
$100, $100 to $200, and everyone over $200 and the medial becomes $100
to $200.

OTOH when it comes to average would they be using gross or taxable
income? Or something else?

Ain't government accounting wonderful. We'd go to jail for using
their math.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com


R.S. Hoover... Well, it may be true that hams are genetically encoded
to be able to solder... OTOH I've seen some ham solder jobs that raise
questions of genetic damage...

Been out in my shop again, huh? I thought I had all those projects
hidden.

Just finished redoing the leading edge of the one elevator
shell...again!. Looks pretty good this time. Now I need to figure out
how to set up a small router to cut out the hinge access points so
they look good. Sand and fill, sand and fill, sand and fill, fill and
sand. (I like to change the routine and add a little variety at
times.)

Today was expensive. 250 Gig WD hard drive failed. Warranty failed
two weeks ago. Display failed on my Kenwood TM-V7A mobile rig. Free
replacement if I purchased it between Jan 1, 2000 and Jan 1, 2006. I
purchased it about the end of May 1999. $160 just for the display but
that does include shipping six bucks for shipping.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

denny
k8do, and a bunch of other initials

Roger:

Just lay out the "U" shape with a fine point marker, the go to work with a
1/2" diameter sanding drum in a Dremil tool. Rough-out the opening, sand
into each corner, free-hand to within 1/16 of the three straignt lines, then
finish sanding by hand with a small sanding stick.

The whole procedure can be completed in less time than it took me to
describe it.


BJC

"Roger" wrote in message
...
On Wed, 15 Mar 2006 17:33:17 -0500, "Morgans"
wrote:


"Roger" wrote

Just finished redoing the leading edge of the one elevator
shell...again!. Looks pretty good this time. Now I need to figure out
how to set up a small router to cut out the hinge access points so
they look good.

I would use a jig, and a router bit to follow the jig. Make a big letter
"O", of whatever size and shape you need, tape it to the surface, and let
the non cutting surface of the bit follow around the inside of the
template,
using rotation to force it to the template. I hope this is clear enough.

That's pretty much what I've been thinking, but the leading edge
curves down and I having come up with a form to follow the edge.
My big router, which is way too big for this job has some bits that
have ball bearings on the shanks for roll along the guide.
I'd like to come up with something like that on a 1/4" bit and I have
some aluminum channel that I could probably form to fit the shape of
the elevator skin. I'd use 1" angle for the back of the cut and run
the angle full length of the skin which would make the cuts uniform.
OTOH it takes a steady hand even with a guide. :-)) It that bit,
bites it can make it through the guides and half way across the shell
in an instant. Then I'd be rebuilding more than the leading edge.
No, I wouldn't. that'd be the point where I called New Glasair and
ordered a new set of elevator skins.

Thanks,

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com