Stuck Ferrule (female end) question

On Jul 6, 12:07*pm, MajorOz wrote:
On Jul 6, 6:15*am, riverman wrote:





On Jul 6, 5:18*am, MajorOz wrote:

On Jul 5, 7:36*pm, riverman wrote:

On Jul 5, 3:27*pm, rw wrote:

On 7/5/10 7:08 AM, rw wrote:

On 7/5/10 5:12 AM, riverman wrote:

I'm not convinced that heat expands the radius of the hole, as in a
photographic enlargement. Objects expand around their physical mass.
There is a classic physics demonstration with a steel ring and a steel
ball where you heat the ring and find that the ball will not fit
through the ring. So, just as the hole in a rising donut (or bagel is
more like it) gets smaller, I would expect the hole to get smaller if
you heated the female section. But countereffecting that would be that
the circumference of the torus would also increase. Maybe there is
some sort of ratio of circumference to torus thickness where the hole
actually does not change....I don't know. But the action of the female
end of a ferrule is a very thought-provoking thing.

http://physics.bu.edu/~duffy/py105/Temperature.html

BTW, I think you're misremembering the ring and ball experiment. It
actually demonstrates just what I (and others) have been saying about
thermal expansion of a hole.

--
Cut "to the chase" for my email address.

You're right. I just saw this on youTubehttp://www.youtube.com/watch?v=V0ETKRz2UCA

So OK, *the hole gets bigger when the female end is heated, however
the male end gets bigger also. Which gets bigger faster?

Read my post. *It explains what and why.

oz

Err, which one, Oz? The one where it says "can't guarantee anything,
but that is the theory" or the one that says "disregard my response"?

:-)

--riverman

They are both sincere (in context), but the one I had in mind was that
the metal will expand or contract with temperature change based on the
original (pick your starting point) temp.

However, they all will change at percentage of the starting size
(assuming identical composition).

To wit: if expansion is X %, a three inch circle will expand to 3 in
+ *X% of three inches, while the little bit less than three inches
will expand to LBLT3in. + X% of LBLT3in, resulting in an ever widening
gap as temp increases.

In sum: the gap between inside and outside widens with increasing
temperature.

Ideally, of course, fill the (hopefully) hollow inside one with water,
freeze the whole mess, then zap the outside QUICKLY with heat and slip
them apart. Kinda like baked Alaska.

Works only with metal. *Obviously not with graphite.

In a sever case in the past of irretrievably stuck graphite ferrules,
I just wound up with a rod five inches shorter.
( Solution left as an exercise -- hint: it involved a jeweler's saw )

cheers

oz- Hide quoted text -

- Show quoted text -

"In sum: the gap between inside and outside widens with increasing
temperature. "
Maby it does in the Russian navy but not anywhere else in the world.