Rod Dynamics ?

Hello:

Was reading a book on ballistics the other day, and the author was
describing conditions
where a rifle barrel would drop a small amount as a shell was fired.

He used an example that if one held a fly rod rod truly horiz., and gave the
handle a very quick
upward (I think he means backwards; toward ones head) pure rotation, the tip
momentarily goes Downward.

Have my rods away for the season, so can't try it.

Can't visualize this happening.

Does it ?
Why does it, if so ?

B.

My knowledge of the actual numbers behind physics is very limited, so
I'll offer up my simple minded version of Newton's Third Law. Could it
be that every action has an equal and opposite reaction?

...but I'm a designer not a physician er, physisonian, or was that a
physisoligist. Oh hell I don't now what I'm talking about.

-Ethan


Robert11 wrote:
Hello:

Was reading a book on ballistics the other day, and the author was
describing conditions
where a rifle barrel would drop a small amount as a shell was fired.

He used an example that if one held a fly rod rod truly horiz., and gave the
handle a very quick
upward (I think he means backwards; toward ones head) pure rotation, the tip
momentarily goes Downward.

Have my rods away for the season, so can't try it.

Can't visualize this happening.

Does it ?
Why does it, if so ?

B.

On Tue, 07 Nov 2006 10:35:15 -0500, daytripper
wrote:

On Tue, 7 Nov 2006 07:47:36 -0500, "Robert11" wrote:

Hello:

Was reading a book on ballistics the other day, and the author was
describing conditions
where a rifle barrel would drop a small amount as a shell was fired.

He used an example that if one held a fly rod rod truly horiz., and gave the
handle a very quick
upward (I think he means backwards; toward ones head) pure rotation, the tip
momentarily goes Downward.

Have my rods away for the season, so can't try it.

Can't visualize this happening.

Does it ?
Why does it, if so ?

B.


I can't see how any downward force vectors at the rod tip increase in this
scenario, so while he's correct that the rod tip will point below horizontal,
it doesn't "drop", it simply lags behind the rest of the rod movement,
establishing an arc...

I s'pose the same thing could happen with rifles, to some (hopefully
vanishingly small) degree...

/daytripper

I'd offer that it would be a bit difficult to hold the average fly rod
"truly horizontal"...unless one just had a lesson or two and the fly rod
in question was the all-new and improved O' Cedar Fishsweeper XLT1000,
for which the instructor was the sole local distributor...

OTOH, I'd offer that any rifle barrel that couldn't be held "truly
horizontal" might make a better fly rod than rifle barrel...

And finally, I'd observe that someone who suggests the physics/mechanics
involved in a rifle barrel at the moment of a round's discharge are
generally the same as someone lifting a fly rod would likely not know
much about either...but on the plus side, they'd be readily recognized
as an expert by some on ROFF...

HTH,
R

On Tue, 07 Nov 2006 10:33:08 -0600, wrote:

On Tue, 07 Nov 2006 10:35:15 -0500, daytripper
wrote:

On Tue, 7 Nov 2006 07:47:36 -0500, "Robert11" wrote:

Hello:

Was reading a book on ballistics the other day, and the author was
describing conditions
where a rifle barrel would drop a small amount as a shell was fired.

He used an example that if one held a fly rod rod truly horiz., and gave the
handle a very quick
upward (I think he means backwards; toward ones head) pure rotation, the tip
momentarily goes Downward.

Have my rods away for the season, so can't try it.

Can't visualize this happening.

Does it ?
Why does it, if so ?

B.


I can't see how any downward force vectors at the rod tip increase in this
scenario, so while he's correct that the rod tip will point below horizontal,
it doesn't "drop", it simply lags behind the rest of the rod movement,
establishing an arc...

I s'pose the same thing could happen with rifles, to some (hopefully
vanishingly small) degree...

/daytripper

I'd offer that it would be a bit difficult to hold the average fly rod
"truly horizontal"...unless one just had a lesson or two and the fly rod
in question was the all-new and improved O' Cedar Fishsweeper XLT1000,
for which the instructor was the sole local distributor...

OTOH, I'd offer that any rifle barrel that couldn't be held "truly
horizontal" might make a better fly rod than rifle barrel...

And finally, I'd observe that someone who suggests the physics/mechanics
involved in a rifle barrel at the moment of a round's discharge are
generally the same as someone lifting a fly rod would likely not know
much about either...but on the plus side, they'd be readily recognized
as an expert by some on ROFF...

HTH,
R

Irony, thy name is Richard.

/daytripper (ahahahahahahahaha!)

"Robert11" wrote in message
...
Hello:

Was reading a book on ballistics the other day, and the author was
describing conditions
where a rifle barrel would drop a small amount as a shell was fired.

He used an example that if one held a fly rod rod truly horiz., and gave
the handle a very quick
upward (I think he means backwards; toward ones head) pure rotation, the
tip momentarily goes Downward.

Have my rods away for the season, so can't try it.

Can't visualize this happening.

Does it ?

Yes

Why does it, if so ?

You might be able to see it more clearly with a full-flex rod as in the case
of bamboo.
While holding the rod in the horizontal position, the start of the arm
motion upward begins the stored energy in the rod and translates it
throughout the length. Since the fly rod has a continuous taper with the
thicker part at the butt and thinning as it progresses towards the tip, the
upswing motion caused the tip to bend momentarily and ever so slightly
downward before it begins to move and follow the rod stroke path.

Not quite sure how the author relates this to rifle ballistics as you
described.
fwiw,
-tom.

wrote:
On Tue, 07 Nov 2006 10:35:15 -0500, daytripper
wrote:

On Tue, 7 Nov 2006 07:47:36 -0500, "Robert11" wrote:

Hello:

Was reading a book on ballistics the other day, and the author was
describing conditions
where a rifle barrel would drop a small amount as a shell was fired.

He used an example that if one held a fly rod rod truly horiz., and gave the
handle a very quick
upward (I think he means backwards; toward ones head) pure rotation, the tip
momentarily goes Downward.

Have my rods away for the season, so can't try it.

Can't visualize this happening.

Does it ?
Why does it, if so ?

B.


I can't see how any downward force vectors at the rod tip increase in this
scenario, so while he's correct that the rod tip will point below horizontal,
it doesn't "drop", it simply lags behind the rest of the rod movement,
establishing an arc...

I s'pose the same thing could happen with rifles, to some (hopefully
vanishingly small) degree...

/daytripper

I'd offer that it would be a bit difficult to hold the average fly rod
"truly horizontal"

Well, you'd never know, would you? So, it's close enough.

...unless one just had a lesson or two and the fly rod
in question was the all-new and improved O' Cedar Fishsweeper XLT1000,
for which the instructor was the sole local distributor...

Zzzzzzzzzzzzzzzzzz

OTOH, I'd offer that any rifle barrel that couldn't be held "truly
horizontal" might make a better fly rod than rifle barrel...

Shows what you know. A rifle barrel can't be held truly
horizontal.......EVERYBODY knows that!

And finally, I'd observe that someone who suggests the physics/mechanics
involved in a rifle barrel at the moment of a round's discharge are
generally the same as someone lifting a fly rod would likely not know
much about either...

If anybody ever suggests that, remind us to ask you to remind
us......o.k.? Meanwhile.....amuse us. Tell us what you know about
either.

but on the plus side, they'd be readily recognized
as an expert by some on ROFF...

And thus, YOU must be a recognized expert on SOMETHING!........right?
Hold your breath.

As for the OP's reference to conditions that would cause a rifle barrel
to drop, I'd be interested in learning what those conditions are and
why the author thought that the alleged downward motion of the flyrod
tip was analagous.

Wolfgang

Tom Nakashima wrote:
"Robert11" wrote in message
...
Hello:

Was reading a book on ballistics the other day, and the author was
describing conditions
where a rifle barrel would drop a small amount as a shell was fired.

He used an example that if one held a fly rod rod truly horiz., and gave
the handle a very quick
upward (I think he means backwards; toward ones head) pure rotation, the
tip momentarily goes Downward.

Have my rods away for the season, so can't try it.

Can't visualize this happening.

Does it ?

Yes

Why does it, if so ?

You might be able to see it more clearly with a full-flex rod as in the case
of bamboo.
While holding the rod in the horizontal position, the start of the arm
motion upward begins the stored energy in the rod and translates it
throughout the length. Since the fly rod has a continuous taper with the
thicker part at the butt and thinning as it progresses towards the tip, the
upswing motion caused the tip to bend momentarily and ever so slightly
downward before it begins to move and follow the rod stroke path.

That explains nothing.

Wolfgang
who suspects that the downward motion is an illusion......but wouldn't
be much surprised if it is in fact real. in either case, recent
developments in the roffian math club suggest rather strongly that a
comprehensible answer will forever remain but a dream.

On Tue, 7 Nov 2006 07:47:36 -0500, "Robert11" wrote:

Hello:

Was reading a book on ballistics the other day, and the author was
describing conditions
where a rifle barrel would drop a small amount as a shell was fired.

He used an example that if one held a fly rod rod truly horiz., and gave the
handle a very quick
upward (I think he means backwards; toward ones head) pure rotation, the tip
momentarily goes Downward.

The moment of inertia of the tip (and every other point on the rod) coupled with
the flexibly of the rod would cause the rod to flex when it was rotated, but it
wouldn't cause the tip to go down - that would violate the conservation of
angular momentum AFAIK.
--
Charlie...
http://www.chocphoto.com

On Nov 7, 6:47 am, "Robert11" wrote:
Hello:

Was reading a book on ballistics the other day, and the author was
describing conditions
where a rifle barrel would drop a small amount as a shell was fired.

It *moves*, yes, and if that movement is downward, then it drops. When
a rifle, or any other firearm, is fired, the barrel vibrates. The
manner in which it does varies with a number of inputs -- length, heat
of combustion, thickness of barrel, bedding, etc. If its bedding or
stocking is such that it kicks in a certain direction, than it can be
drilled near the muzzle to use escaping gasses to overcome this
tendency.-

He used an example that if one held a fly rod rod truly horiz., and gave the
handle a very quick
upward (I think he means backwards; toward ones head) pure rotation, the tip
momentarily goes Downward.

Have my rods away for the season, so can't try it.

Can't visualize this happening.

Does it ?
Why does it, if so ?

It does, for reasons that Tom outlined. An outdoor writer mentioned
this in a magazine article LOOOOOOOONG ago (I think it was Trueblood in
F&S). He was fishing for short-strike bluegills, using a vintage
bamboo (read "noodle") rod. At the strike, the tip DROPPED when he
pulled up. So he had to overcome natural reflex and, as he stated it,
"...swat at them like swatting flies with the rod tip" to tighten the
line for the strike.

cheers

oz

MajorOz wrote:
On Nov 7, 6:47 am, "Robert11" wrote:
Hello:

Was reading a book on ballistics the other day, and the author was
describing conditions
where a rifle barrel would drop a small amount as a shell was fired.

It *moves*, yes, and if that movement is downward, then it drops. When
a rifle, or any other firearm, is fired, the barrel vibrates. The
manner in which it does varies with a number of inputs -- length, heat
of combustion, thickness of barrel, bedding, etc. If its bedding or
stocking is such that it kicks in a certain direction, than it can be
drilled near the muzzle to use escaping gasses to overcome this
tendency.-

He used an example that if one held a fly rod rod truly horiz., and gave the
handle a very quick
upward (I think he means backwards; toward ones head) pure rotation, the tip
momentarily goes Downward.

Have my rods away for the season, so can't try it.

Can't visualize this happening.

Does it ?
Why does it, if so ?

It does, for reasons that Tom outlined. An outdoor writer mentioned
this in a magazine article LOOOOOOOONG ago (I think it was Trueblood in
F&S). He was fishing for short-strike bluegills, using a vintage
bamboo (read "noodle") rod. At the strike, the tip DROPPED when he
pulled up. So he had to overcome natural reflex and, as he stated it,
"...swat at them like swatting flies with the rod tip" to tighten the
line for the strike.

Horse****.

Wolfgang