So there I am, my usual lovable self, ****ing & moaning about all
these
HOT projects that I've been ****ing & moaning about for the last
couple of years, NOW using a simple case of cancer as my excuse for
not getting anything done... and one of my regular cage-rattlers sez:
'So what ARE these hot projects? Is there anything on them that WE
could work on?'

Which brings me down a notch or two in a hurry.
Calling my hand. Well... okay.

Howzabout Nav Lights? Have you guys even SEEN what they want for your
basic Grimes light nowadays? Not Grimes of course; somebody else...
Whelen, I think. Back in the Day we went down to Western Auto, across
the street from the Greyhound bus station, bought a red, a green and a
clear -- truck clearance lights, as required by the ICC (yep, green &
amber too). The lights were kinda cone-shaped... about 28B, if you
get my drift.

So how do you streamline your 28B nav light? Turns out, you can
reduce the drag of your 28B's by about 90% by simply building a vane
on the down-wind side; something to keep the burble created by the
displaced air from mixing together. The vane could be anything at
all.. plastic, aluminum, 1/16" plywood... whatever came to hand. Of
course, if you gotta roll your own, why not make it a fully
streamlined housing? About a thousand times more work but sexy as the
devil.

And since this is Experimental Aviation we may as well go ahead and
use a couple of those high-intensity, high-wattage LED lamps. That
way, we can seal everything up. No need to provide for replacement
when the lamps have a longer service-life than the airframe.

Of course, we still gotta make that streamlined GREEN housing... and a
red one, too.

Where do you find GREEN plastic nowadays? Well... I found some at Wal-
Mart. In the shape of a pill bottle. Full of Vitamin C tablets.

Of course, once we've found our green bottle-shaped plastic we gotta
turn it into a SHEET of plastic, which means cutting the ends offen
the bottle, slitting it down the side, heating it in cooking oil then
laying it out flat. Or even PRESSING it out flat, if it don't want to
lay there. That means some flat.. somethings. Precision tooling
plate is pretty flat. So's a surface plate. But a pair of polished
granite tile is something available to all (at least, all here in the
States).

So now we got a sheet of FLAT green plastic. Sorta thin and I don't
know how well it will stand up to ultra-violet. Go ahead and hang that
puppy out the window until you need it.

Making the MOLD is pretty easy... once you know how. You can make
your mold out of Plaster of Paris or spackling paste or Portland
cement or... all kinds of things lend themselves to making molds.
Once you know HOW to make molds. The tricky bit is conveying the HOW
using only printed words, which is virtually impossible. Whatcha need
is PICTURES. Lots of them. And this GROUP doesn't allow them. So
before I could worry about showing folks how, I had to find someplace
to hang pictures. Did that... Blog and the chuggers Group allows
pictures.

So... you wanted to know what some of those Hot Projects were? Nav
Lights is just one. And yes, I see you, there in the back waving your
hands saying why do you even need nav lights since were Day-VFR
anyway, or that you only fly out of the south forty.

We need nav lights because a lot of folks aren't you. If you live in
the western United States there's plenty of places that are far enough
apart that you can't accurately predict your arrival time, such as
flying from Sandy Eggo to Lost Wages. Get a head-wind and you'll find
yourself crossing some of the emptiest land on the planet. Now, lots
of folks simply don't believe that but there's a sign beside the
Interstate outside of Barstow that warns folks the next services are
over a hundred miles away. It's even farther if you're driving an
aeroplane.

Big EMPTY country out here. Why do you think it took them so long to
find Fawcett? This AIN'T your south forty. So you're chugging along,
lotsa fuel, and you notice your landmarks seem to be standing still.
Little later you notice you're flying BACKWARDS over your landmarks!
Don't laugh, it happens. Get a big high pressure area over Utah,
there's plenty of days when you simply can't fly from San Diego to Las
Vegas. The winds will reduce your actual ground-speed to only ten or
fifteen miles per hour. And while there's lots of landing strips
(See: 'Where Am I?' on my blog ) most of them date from WWII and
don't offer any services. Some are owned by various 'Agencies' with
alphabet soup instead of names. And they are definitely not happy to
see you dropping in on them, asking for a couple gallons of gas. So
how do you get from here to there? Go to Yuma and hang a left. Fly
up the Colorado River corridor. Hundred miles outta your way but
several airfields to help you out.

So why the nav lights? Because of that high pressure area over Utah.
Slows you down so that your arrival dictates a night landing... and a
bit of night flying. And that's why you need those nav lights.

Now -- who wants to tackle this particular Hot Project?

-R.S.Hoover

wrote:

>
> And since this is Experimental Aviation we may as well go ahead and
> use a couple of those high-intensity, high-wattage LED lamps. That
> way, we can seal everything up. No need to provide for replacement
> when the lamps have a longer service-life than the airframe.
>
> Of course, we still gotta make that streamlined GREEN housing... and a
> red one, too.
>
> Where do you find GREEN plastic nowadays? Well... I found some at Wal-
> Mart. In the shape of a pill bottle. Full of Vitamin C tablets.
>

>

> -R.S.Hoover

Can't a guy just use clear lexan? Or, maybe there's white plastic so
that it would turn the color of the LED illuminating it? LEDs come in
red, green, white, blue, yellow, etc...

Scott

Scott wrote:
> wrote:
>
>>
>> And since this is Experimental Aviation we may as well go ahead and
>> use a couple of those high-intensity, high-wattage LED lamps. That
>> way, we can seal everything up. No need to provide for replacement
>> when the lamps have a longer service-life than the airframe.
>>
>> Of course, we still gotta make that streamlined GREEN housing... and a
>> red one, too.
>>
>> Where do you find GREEN plastic nowadays? Well... I found some at Wal-
>> Mart. In the shape of a pill bottle. Full of Vitamin C tablets.
>>
>
>>
>
>> -R.S.Hoover
>
> Can't a guy just use clear lexan? Or, maybe there's white plastic so
> that it would turn the color of the LED illuminating it? LEDs come in
> red, green, white, blue, yellow, etc...
>
> Scott
>

I bought some 12" x 24" pieces of plexiglass in red, yellow and green
on e-bay a few years ago. The local glass supply here will only order in
4' x 8' sheets and rarely have smaller pieces for sale.

Dan, U.S. Air Force, retired

Why not just use CLEAR plastic. Lots of that stuff around. The chemistry
of the LEDs will take care of the color. The only reason that you use
colored plastic on incandescent lights is that they only come in one color.

Jim


>
> Of course, we still gotta make that streamlined GREEN housing... and a
> red one, too.
>
> Where do you find GREEN plastic nowadays? Well... I found some at Wal-
> Mart. In the shape of a pill bottle. Full of Vitamin C tablets.

Google for your closest TAP Plastics store. They have scraps in all colors
of the rainbow.

Jim

--
"It is the mark of an educated mind to be able to entertain a thought
without accepting it."
--Aristotle


>
> I bought some 12" x 24" pieces of plexiglass in red, yellow and green on
> e-bay a few years ago. The local glass supply here will only order in 4' x
> 8' sheets and rarely have smaller pieces for sale.
>
> Dan, U.S. Air Force, retired

RST Engineering wrote:
> Why not just use CLEAR plastic. Lots of that stuff around. The chemistry
> of the LEDs will take care of the color. The only reason that you use
> colored plastic on incandescent lights is that they only come in one color.
>
> Jim
>

Another advantage of using the clear plastic is that it is possible to
get AR grade scraps. The AR grade is scratch and UV resistant. I also
found it to be much less brittle that any plexiglass or lexan I've ever
worked with in the past. I was able to cut the 1/8" sheet very
effectively with a pair of sheet metal shears (then I cleaned the sides
up with a belt sander, followed by a 400grit sanding block).

Ernest Christley wrote:
> RST Engineering wrote:
>
>> Why not just use CLEAR plastic. Lots of that stuff around. The
>> chemistry of the LEDs will take care of the color. The only reason
>> that you use colored plastic on incandescent lights is that they only
>> come in one color.
>>
>> Jim
>>
>
> Another advantage of using the clear plastic is that it is possible to
> get AR grade scraps. The AR grade is scratch and UV resistant. I also
> found it to be much less brittle that any plexiglass or lexan I've ever
> worked with in the past. I was able to cut the 1/8" sheet very
> effectively with a pair of sheet metal shears (then I cleaned the sides
> up with a belt sander, followed by a 400grit sanding block).


Nice for flat parts, but how does it heat form?

--

Richard

(remove the X to email)

> wrote in message
...
> So there I am, my usual lovable self, ****ing & moaning about all
> these
> HOT projects that I've been ****ing & moaning about for the last
> couple of years, NOW using a simple case of cancer as my excuse for
> not getting anything done... and one of my regular cage-rattlers sez:
> 'So what ARE these hot projects? Is there anything on them that WE
> could work on?'



> So why the nav lights? Because of that high pressure area over Utah.
> Slows you down so that your arrival dictates a night landing... and a
> bit of night flying. And that's why you need those nav lights.
>
> Now -- who wants to tackle this particular Hot Project?
>
> -R.S.Hoover


Bob,

I am able to mooch all the scrap acrylic plastic I need for my projects from
my local electric sign shop. In colors, both translucent and
transparent/tinted.

I have connections to the industry, but that doesn't seem to perjudice them.
Mostly, they are happy to have someone remove some scrap. Bigger shops
accumulate bigger pieces and bigger piles.

Flash

> wrote
>
> So why the nav lights? Because of that high pressure area over Utah.
> Slows you down so that your arrival dictates a night landing... and a
> bit of night flying. And that's why you need those nav lights.
>
> Now -- who wants to tackle this particular Hot Project?

An easy way out might be to use an available LED bulb, and roll your own
reflector.

<http://www.ledlight.com/> has a ton of bulbs, or perhaps would be a way to
get some LED's cheap by taking apart a bulb.
--
Jim in NC

Can't you just find red and green lenses on an old
boat in a boat junk yard?
Lou

cavelamb himself wrote:

>> Another advantage of using the clear plastic is that it is possible to
>> get AR grade scraps. The AR grade is scratch and UV resistant. I
>> also found it to be much less brittle that any plexiglass or lexan
>> I've ever worked with in the past. I was able to cut the 1/8" sheet
>> very effectively with a pair of sheet metal shears (then I cleaned the
>> sides up with a belt sander, followed by a 400grit sanding block).
>
>
> Nice for flat parts, but how does it heat form?
>

I haven't tried it yet, but it sounds like a "hot project" that I need
to get around to.

"cavelamb himself" > wrote

> Nice for flat parts, but how does it heat form?

Do some googling over in rec.models.rc.air. The subject comes up fairly
often, as it has around here, as I seem to recall.

There is a need to get a very smooth mold, and cover it in felt, or have a
very perfect hard plug. Any cloth with texture will transfer the weave to
the plastic.

You mound the plastic in a frame, and either pull mold it onto the plug
(which is sticking up off the table, so you can pull well past the bottom of
the mold) or vacuum mold it. Wait until the material starts to sag pretty
good, and stick it over the mold and pull, or use the vacuum table method,
if it is a complex part.

The only major difference (other than a slightly different heat requirement)
between plexi and lexan, is that you need to bring the lexan up to over 250
degrees and keep it there for an hour or so , to drive the moisture out of
the plastic. Weird, that there can be water in plastic, to me! <g>

You just have to look at the material and get the right timing when it sags
just right. Also, that your part will only be as good as your mold.

Also, sports fans, remember to fix up a special drill bit before you drill
the plastic to mount it. Use a dremel, and grind a couple degrees negative
angle on the bit, so it scrapes the plastic, rather than pulling through the
plastic, and cracking it.
--
Jim in NC