Post by Cliff HuprichPost by BottleBobLet me try to simplify this by asking a few questions.
Are you doubting that many fusible alloys expand when they
solidify/cool?
Which of the two are you asking about? Be clear ...
Cliff:
Sounds like you're being Cliffasive again (copytrite BB 10-26-03). But
in the off chance that you're not, let me separate the questions:
Are you doubting that many fusible alloys expand when they
solidify?
Are you doubting that many fusible alloys expand when they
cool?
Post by Cliff HuprichPost by BottleBob*IF* we have say a 6" X 6" X 2" box, and we put a 3" X 3" X 1" straight
sided part in this box and then pour in some fusible alloy that expands
when it solidifies/cools to almost the the 1" height of the part . Will
the expansion of the
fusible alloy pull away from the part or "squeeze" the part?
Probably.
Probably what, pull away, or squeeze? So are you conceding that you
have absolutely NO idea whatsoever WHAT it will do?
Well, in the interest of science, I did a little experiment last night
at home that anyone can repeat. I don't have any expanding Cerrobend,
but I do have access to expanding water. So I got an old aluminum pan,
found a glass with tapered sides (small at the base - large at the top),
put the glass in the pan (base side down of course) and added about 1"
of water around it, then put it in the freezer. This morning I took
the pan&glass out of the refrigerator. Then I tried to pull the glass
out of the ice. I couldn't get it out, even by supporting my wrists on
the pan and squeezing up with all my force. That glass was REALLY STUCK
in there. And it was smooth with no undercuts or protrusions to hold
it. And while one experiment is hardly unimpeachable conclusive
evidence, it does tend put a damper on the "expand away from the part"
hypothesis.
Post by Cliff HuprichPost by BottleBobRealize
the while the material is solidifying/cooling, and expanding, it's going
to be pushing on it's own molecules AND the walls of the outer box.
And upwards?
Yes. And upwards. The ice in my little pan&glass experiment WAS
pushed upward on one side of the pan.
Post by Cliff HuprichPost by BottleBobNow conversely, say we have the same boxes as above but we pour in some
lead that shrinks when it solidifies/cools. Will the shrinkage of the
lead pull away from the part or "squeeze" the part?
Have you added a flux? What are things made of?
You're being Cliffasive again.
Post by Cliff HuprichPost by BottleBobPost by Cliff HuprichPost by BottleBobAnd by using your unrelated example
you arrived at a conclusion that would be incorrect when applied to
using fusible alloys in "box fixtures" for holding irregular shaped
parts for machining.
Expansion is expansion. Contraction is contraction.
Be it a toolholder getting warmer/cooler or anything else.
You know it's not that simple since different geometric forms have
different vectors during expansion.
Huh??? It's a uniform linear effect, all else being constant.
OH? Band-saw that shrink-fit toolholder in half axially and THEN heat
it up. Will the half-ID radius pull away from the original centerline
like a whole toolholder would?
Post by Cliff HuprichPost by BottleBobThe shrink-fit toolholder being one
case where the ID grows with the OD due to it's geometry.
So it's an exception because it has two circles?
Cut it in half, heat it up, and let's see what happens.
Post by Cliff HuprichWhen does the ID exceed the OD?
When a person named Cliff starts applying his mythical "sufficiently
large value of zero" tautological "logic".
Post by Cliff HuprichPost by BottleBobOr perhaps the Cerrobend pushed equally in all directions, upon it's
own molecules AND the outer box as well as the inner part.
This is actually your first post where you want to add a box .. perhaps
it's the box shrinking as it cools ? LOL ....
Your story keeps changing ..
Sorry to contradict, but you're incorrect. My very FIRST post to this
thread mentions using a "box". Here, let me refresh your faulty memory:
============================================
From:
BottleBob <***@earthlink.net>
Newsgroups:
alt.machines.cnc
Subject:
Re: Anyone using Fusible Alloys?
Date:
Sat, 25 Oct 2003 01:13:44 GMT
Post by Cliff HuprichPost by BottleBobBesides the low melting temp, thae other nice thing is that it expands when
it cools.
So the part would loosen?
Cliff:
If a part was put in a "box" and then surrounded with
Cerrobend/Wood's
metal or whatever, and the material expanded when it cooled, why do you
think the part would loosen? It would be "squeezed" on all four sides,
would it not?
===================================================
I also mentioned using "box fixtures" in an additional post to this
thread. You replied to both of my posts where I mentioned using a
"box", so it's not that you're missing some posts.
Post by Cliff HuprichPost by BottleBobPost by Cliff HuprichIf you have an expanding mandrel does it matter if you are trying to
hold a part by it's OD or ID? Do you get better clamping on the OD when
you expand the mandrel on the part's OD?
I don't understand your question, or see how it relates to the
expansion of Cerrobend. It's my understanding that expanding mandrels
hold parts on their ID. I've never seen an expanding mandrel hold a
part on it's OD. That would be a collet or a chuck.
Collet/mandrel ... answer the question ....
You talked about using an expanding mandrel to clamp on the ID and THEN
on the OD. If you wish me to answer the question, please rephrase it
into something intelligible.
Post by Cliff HuprichPost by BottleBobPost by Cliff HuprichWhat happens to that shrink-fit toolholder as you heat it and it
expands? Does the ID get smaller?
The expansion of the ID of an already solid shrink-fit toolholer is an
artifact of it's geometric form. I don't think you can use this
particular case to support a general position where a liquid fusible
alloy would pull away from a part inside a box.
Not the question ..... and NOW it's liquid .... you been taking jb's meds?
The entire subject is about using fusible alloys. You heat them up,
pour them into your holding fixture as a LIQUID, and let them solidify.
Post by Cliff HuprichPost by BottleBobNot exactly sure what you're looking for, but here's a site that give
===================================================
http://www.harpellassociates.com/a/a-fusible.htm
When Bismuth is alloyed with other metals, such as Lead, Tin, Cadmium
and Indium, this expansion is modified according to the relative
percentages of
Bismuth and other components present. As a general rule, Bismuth alloys
of approximately 50 percent Bismuth exhibit little change of volume
during solidification. Alloys containing more than this tend to expand
during solidification and those containing less tend to shrink during
solidification.
After solidification, alloys containing both Bismuth and Lead in
optimum proportions grow in the solid state many hours afterwards.
Bismuth alloys that do not contain Lead expand during solidification,
with negligible shrinkage while cooling to room temperature.
==================================================
The latter is a phase change from liquid to solid.
So?
Post by Cliff HuprichThe question is about changes in the solid as it gets cooler .... does
it expand?
That was *ONE* question, but not the *ONLY* question. Did you even
bother to GO to the site listed above and look at the charts? One chart
shows the expansion of various fusible alloys after casting. The time
frames go from 2 minutes to 21 DAYS! And after 21 days, some fusible
alloys are STILL expanding. And that's on a 2" X 2" X 10" bar.
Post by Cliff HuprichPost by BottleBobWhen you make popsicles in your ice cube tray, do the popsicles shrink
away from the popsicle sticks? If THAT were the case then we wouldn't
even HAVE such a thing as popsicles, we'd have to eat them with a fork.
You need to learn ....
I'm always willing to learn something I don't know, from ANY source.
Did you perhaps have something you wished to teach me about making
popsicles?
Post by Cliff HuprichPost by BottleBobPost by Cliff HuprichIF I get bored enough later I may write you a little essay on that circle
(actually, any closed curve OR surface) and the conservation laws. It's
probably at least as important a concept as the Null Set or the Theory
of Limits (or the concept of conservation laws).
No No, not your mythical "sufficiently large value of zero"
tautological theory of limits again? LOL
Closed curves? See "Niven's law" at
http://www.math.siu.edu/kocik/tm/tm-dic.htm
Now Larry Niven is/was a sci-fi writer I DO like.
Post by Cliff HuprichAlso "Rotating Cylinders and the Possibility of Global Causality Violation".
Yeah, that guy Clifford A Pickover sounds like he writes some
interesting stuff. A few of he earlier publications follow:
The Alien IQ Test (Basic Books, 1997), The Loom of God (Plenum, 1997),
Black Holes - A Traveler's Guide (Wiley, 1996)
Or maybe you just like him because he has the same first name as you.
--
BottleBob
http://home.earthlink.net/~bottlbob