March 19th 06, 11:34 AM
In August of 2005 I posted a message that offered a few hints about
some alternatives to the lathe. In that message I said, "The most
common thing used to rotate the work is the ubiquitous quarter-inch
drill-motor."
I did so because I assumed everyone would be familiar with the many
jigs and fixtures designed to clamp a drill-motor to your work bench,
allowing you to use it as a grinder, scratch-wheel or whatever.
Turns out, a lot of folks had no idea in the blue-eyed world what I was
talking about. (Which tends to happen more often, the older I get :-)
Back in the Good Ol' Days, whenever that was for you, when you finally
got rich enough to afford a quarter-inch electric drill-motor there was
a whole raft of accessories and attachments you could buy to go with
it, allowing your drill-motor to serve as a drill press, bench grinder,
tire pump and so on. The most basic of those attachments was a sturdy
base that bolted to your bench and to which your drill-motor could be
fastened. Chuck a wire brush in your drill-motor and you had a
scratch-wheel; a mounted grind-stone turned it into a bench grinder.
So what's that got to do with the lathe business?
I recently told a feller how he could use a piece of brazing rod as an
antenna. Even gave him a piece of sixteenth-inch brass rod to get him
started. He had to order the connector because he was using a BNC
fitting and all I had was some big ol' PL-259's - - what they usta call
'UHF' connectors, even though they weren't. UHF, that is.
The reason he had BNC's was because he ran a lead to the belly of his
plane soz he could attach his rubber ducky. And it worked a treat, so
long as he was in the air. But once he landed, his rubber ducky was
down in the weeds and so was his signal, which ain't much using that
small of an antenna, which was about nine inches long.
Quarter-wave for aviation communication frequencies is about two
feet... something like that. (I'll let all the experts jump on that
one :-) So I suggested he replace the rubber ducky with a quarter-wave
and see if that didn't help.
When the feller got the BNC connector (eighty cents but he had to send
away for it) he sees that the center pin is smaller than the brazing
rod. In fact, the center pin is about .050" whereas the brazing rod
was an honest sixteenth of an inch. (The idea here is that the brazing
rod REPLACES the center pin.) Now, the truth is, a BNC connector --
the female part -- is more than willing to accept a .0625" dia pin,
assuming you put a bit of point on it and don't just jab it in there.
But he was afraid of ruining the connector on his belly pan so he came
by the shop and asked if I'd turn down the brazing rod to match the BNC
connector.
Which I did. But what surprised him was that I didn't use the lathe.
I'd just gotten the cylinder of an itty-bitty steam engine secured to
the cross-feed... had the boring bar all set up and had spent mebbe an
hour getting ready to make a cut that would take about ten minutes and
didn't want to tear it down and start over. Nor did I want to do the
work with someone peering over my shoulder.
I pulled the drill-motor stand out from under the bench, installed the
drill-motor then clamped it down. Chucking a sixteenth inch bit, I
used a piece of scrap wood as my 'tail-stock' and pushed it onto the
spinning drill bit, which gave me a sixteenth inch hole on exactly the
same level as the chuck of the drill-motor. Then I replaced the drill
bit with the piece of brazing rod, inserting its free end through the
hole I'd just drilled in the scrap of wood. I used another C-clamp to
secure the scrap of wood to the bench, roughly aligned with the
drill-motor, so that about half an inch of the rod was poking free on
the other side. Then I turned on the drill-motor and used a fine-tooth
single-cut file to 'machine' the end of the brazing rod about .050",
givertake. All of which took less time to do than to describe.
--------------------------------------------------------------------
Last summer I hinted that not having a lathe didn't mean you were dead
in the water when it came to producing a few turned parts. Some of the
comments I got told me that Common Sense was pretty uncommon stuff on
RAH because the simple truth is that even when DO have a lathe... and a
milling machine and a whole shop full of tools, often times you can do
a job faster using whatever happens to be available, plus a bit of
common sense.
--------------------------------------------------------------------
As for the COM antenna, you dip the tip in a solder pot, which in my
shop was a .22 cal. shell casing fulla solder and heated with a torch.
To secure it in the male BNC connector, which was the crimp-on type,
intended for coaxial cable, you distress the brass near the tip to give
it some tooth then slide a Delrin collar down the wire to fill the
ferule. Now you squeeze it, compressing the ferule onto the collar and
the collar onto the rod and seal the whole sheebang with three
graduated lengths of heat-shrink tubing. And there's your COM antenna.
Cost you mebbe a buck. (No, I don't what the SWR will be -- I've no
idea what kind of ground-plane he's got.)
When you install your brazing-rod antenna (or any other, for that
matter), wrap the connector with 'Coax-Seal.' That's a brand-name, by
the way. Radio type personnel usually got some in their pocket. If
not, you can order it. It looks like electrical tape only thicker and
not as wide and has the texture of unvulcanized rubber. Wrap the
connector then mold the edges of your wrappings with your fingers.
(I've been atop radio towers down in Mexico where the osprey-**** was a
foot thick and the only thing left of the antennas was the Coax-Seal,
which was still pliable after twenty years.)
-----------------------------------------------------------------------------
So... did going to a half-wave antenna solve his 'Say Again' problems?
I donno... yet. A better solution would be to position the antenna
somewhere on the TOP of the aircraft. Yeah, I know... you're flying
OVER the tower. But trust me here, they'll hear you just as good...
and a whole lot better when you're on the ground over behind the
hangar.
-R.S.Hoover
some alternatives to the lathe. In that message I said, "The most
common thing used to rotate the work is the ubiquitous quarter-inch
drill-motor."
I did so because I assumed everyone would be familiar with the many
jigs and fixtures designed to clamp a drill-motor to your work bench,
allowing you to use it as a grinder, scratch-wheel or whatever.
Turns out, a lot of folks had no idea in the blue-eyed world what I was
talking about. (Which tends to happen more often, the older I get :-)
Back in the Good Ol' Days, whenever that was for you, when you finally
got rich enough to afford a quarter-inch electric drill-motor there was
a whole raft of accessories and attachments you could buy to go with
it, allowing your drill-motor to serve as a drill press, bench grinder,
tire pump and so on. The most basic of those attachments was a sturdy
base that bolted to your bench and to which your drill-motor could be
fastened. Chuck a wire brush in your drill-motor and you had a
scratch-wheel; a mounted grind-stone turned it into a bench grinder.
So what's that got to do with the lathe business?
I recently told a feller how he could use a piece of brazing rod as an
antenna. Even gave him a piece of sixteenth-inch brass rod to get him
started. He had to order the connector because he was using a BNC
fitting and all I had was some big ol' PL-259's - - what they usta call
'UHF' connectors, even though they weren't. UHF, that is.
The reason he had BNC's was because he ran a lead to the belly of his
plane soz he could attach his rubber ducky. And it worked a treat, so
long as he was in the air. But once he landed, his rubber ducky was
down in the weeds and so was his signal, which ain't much using that
small of an antenna, which was about nine inches long.
Quarter-wave for aviation communication frequencies is about two
feet... something like that. (I'll let all the experts jump on that
one :-) So I suggested he replace the rubber ducky with a quarter-wave
and see if that didn't help.
When the feller got the BNC connector (eighty cents but he had to send
away for it) he sees that the center pin is smaller than the brazing
rod. In fact, the center pin is about .050" whereas the brazing rod
was an honest sixteenth of an inch. (The idea here is that the brazing
rod REPLACES the center pin.) Now, the truth is, a BNC connector --
the female part -- is more than willing to accept a .0625" dia pin,
assuming you put a bit of point on it and don't just jab it in there.
But he was afraid of ruining the connector on his belly pan so he came
by the shop and asked if I'd turn down the brazing rod to match the BNC
connector.
Which I did. But what surprised him was that I didn't use the lathe.
I'd just gotten the cylinder of an itty-bitty steam engine secured to
the cross-feed... had the boring bar all set up and had spent mebbe an
hour getting ready to make a cut that would take about ten minutes and
didn't want to tear it down and start over. Nor did I want to do the
work with someone peering over my shoulder.
I pulled the drill-motor stand out from under the bench, installed the
drill-motor then clamped it down. Chucking a sixteenth inch bit, I
used a piece of scrap wood as my 'tail-stock' and pushed it onto the
spinning drill bit, which gave me a sixteenth inch hole on exactly the
same level as the chuck of the drill-motor. Then I replaced the drill
bit with the piece of brazing rod, inserting its free end through the
hole I'd just drilled in the scrap of wood. I used another C-clamp to
secure the scrap of wood to the bench, roughly aligned with the
drill-motor, so that about half an inch of the rod was poking free on
the other side. Then I turned on the drill-motor and used a fine-tooth
single-cut file to 'machine' the end of the brazing rod about .050",
givertake. All of which took less time to do than to describe.
--------------------------------------------------------------------
Last summer I hinted that not having a lathe didn't mean you were dead
in the water when it came to producing a few turned parts. Some of the
comments I got told me that Common Sense was pretty uncommon stuff on
RAH because the simple truth is that even when DO have a lathe... and a
milling machine and a whole shop full of tools, often times you can do
a job faster using whatever happens to be available, plus a bit of
common sense.
--------------------------------------------------------------------
As for the COM antenna, you dip the tip in a solder pot, which in my
shop was a .22 cal. shell casing fulla solder and heated with a torch.
To secure it in the male BNC connector, which was the crimp-on type,
intended for coaxial cable, you distress the brass near the tip to give
it some tooth then slide a Delrin collar down the wire to fill the
ferule. Now you squeeze it, compressing the ferule onto the collar and
the collar onto the rod and seal the whole sheebang with three
graduated lengths of heat-shrink tubing. And there's your COM antenna.
Cost you mebbe a buck. (No, I don't what the SWR will be -- I've no
idea what kind of ground-plane he's got.)
When you install your brazing-rod antenna (or any other, for that
matter), wrap the connector with 'Coax-Seal.' That's a brand-name, by
the way. Radio type personnel usually got some in their pocket. If
not, you can order it. It looks like electrical tape only thicker and
not as wide and has the texture of unvulcanized rubber. Wrap the
connector then mold the edges of your wrappings with your fingers.
(I've been atop radio towers down in Mexico where the osprey-**** was a
foot thick and the only thing left of the antennas was the Coax-Seal,
which was still pliable after twenty years.)
-----------------------------------------------------------------------------
So... did going to a half-wave antenna solve his 'Say Again' problems?
I donno... yet. A better solution would be to position the antenna
somewhere on the TOP of the aircraft. Yeah, I know... you're flying
OVER the tower. But trust me here, they'll hear you just as good...
and a whole lot better when you're on the ground over behind the
hangar.
-R.S.Hoover