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On Tue, 5 Mar 2002 18:26:21 GMT, "Thomas Avery"
<thomas.avery@intec-hou.com> wrote:
> In lugnet.technic, Tobbe Arnesson writes:
> <snip>
> > 5) After a few turns (got a soft axle) a "snap" was heard and there
> > was pieces falling... from the non-boiled gear!
>
> Ha! How about that? We now have one confirmed test that gear-boiling works.
>
> Anyone care to speculate on the physics behind this?
I talked to my co-worker who's a rock climber about this interesting
matter and he claims that climb ropes get better and better from
stress regarding max weight/pull capabilites, however they also get
crispier. Climbing ropes are generally made of nylon.
So there seems to be some form of relocation in the atoms when nylon
is heated that makes it harder.
If I can figure out a way to test the stress induced on a LEGO gear I
might say how much "better" it get's in various aspects. Don't know
how many gears I'm willing to sacrifice on this though 8-)
/Tobbe
http://www.arnesson.nu/lotek/
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In lugnet.technic, Tobbe Arnesson writes:
> I talked to my co-worker who's a rock climber about this interesting
> matter and he claims that climb ropes get better and better from
> stress regarding max weight/pull capabilites, however they also get
> crispier. Climbing ropes are generally made of nylon.
>
> So there seems to be some form of relocation in the atoms when nylon
> is heated that makes it harder.
>
> If I can figure out a way to test the stress induced on a LEGO gear I
> might say how much "better" it get's in various aspects. Don't know
> how many gears I'm willing to sacrifice on this though 8-)
This is just a wild thought, but what if the boiling process doesn't alter
the the strength of the material, but helps to reduce stress concentration
points?
If the gear deforms ever so slightly (i.e. negligible deformation- no change
when viewed with the human eye), perhaps microscopic cracks and other
geometric irrgularities are "filled in" and smoothed over. This will
increase the strength of the gear, but not significantly.
Your test only demonstrates the strength of the boiled gear relative to the
non-boiled gear. It doesn't measure a magnitude of increased strength.
Perhaps the boiled gear is just slightly stronger?
I dunno. Just thinkin'...
TJ
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I hahe been lurking on this conversation for a bit. Here are some random
thoughts:
Blocks, Gears and Axles use three different materials. By that I mean the
are differnet grades of the same material or totally different materials. I
lean towards totally different materials, but what do I know? I am an IT
guy, not a materials engineer.
I have had both gear failures and axle failures.
Axle failures are almost always caused (for me) by trying to transmit a
large amount of torque over a long distance. The axle twists and eventually
fails.
Gear failure are almost always on non-axle driven gears (free spinning on
the axle and the teeth break) or gears attached to very short axles (and the
axle connection gives).
It would take some scientific testing to be sure, but I am almost positive
that what we are seeing is the boiled gear stretches less, so holds together
longer, but I would expect the failure is always catastrophic (the gear
snaps), versus a non-boiled gear which stretchesw first and then snaps.
Just a wild guess.
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