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FUT: lugnet.technic
On Tue, 5 Mar 2002 00:02:51 GMT, "Thomas Avery"
<thomas.avery@intec-hou.com> wrote:
> I recently received an email from someone about strengthening gears. This
> person claims that by boiling the gears and then cooling them with cold
> water, their strength will increase.
>
> Has anyone tried this? What were your results?
There's a lot of talk and little workshop here.
I know nothing about gear streangth, I have never broken a gear -
unitl today.
Feeling the only way to settle this is to actually test it:
1) I took a z16 gear and boiled it in five minutes, I live at an
altitude of aprox. 200 meter above sea level so the water should have
been around 100 degrees Celcius.
2) I put the gear in cold water
3) I could see no changes on the gear
4) I made a device alowing me to put a lot of stress on the gear
meshing with another z16 picked at random in my collection
5) After a few turns (got a soft axle) a "snap" was heard and there
was pieces falling... from the non-boiled gear!
6) I repeted the test and the non-boiled gear gave in after half a
twist.
7) Another try, this time moving the doped (boiled) gear to the other
position in the device, just to make sure there was no difference in
where the gear was. And again the non-boiled gear broke.
At this stage, when the doped gear hold for three non-doped gears I
thougth it was enough. Of course I should have boiled three gears and
made sure there was no difference there but...
Pictures: http://www.brickshelf.com/cgi-bin/gallery.cgi?i=132064
I have them in full resolution if needed.
/Tobbe
http://www.arnesson.nu/lotek/
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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?
TJ
p.s. Thanks Tobbe for sacrificing your gears and axles.
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In lugnet.technic, Tobbe Arnesson writes:
> There's a lot of talk and little workshop here...
<snip>
Tobbe,
Was there any noticeable deformation of the boiled gear? For example, did it
have any out-of-roundness (i.e. ovalization) and/or was it warped?
Thanks,
TJ
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> In lugnet.technic, Tobbe Arnesson writes:
> > There's a lot of talk and little workshop here...
> <snip>
>
> Tobbe,
>
> Was there any noticeable deformation of the boiled gear? For example, did it
> have any out-of-roundness (i.e. ovalization) and/or was it warped?
*digging through layers of bins and instructions to find my slide
calliper*
Okay, measuring from one side, two gear tops resting on the caliper on
each side the gear is 17.50 mm and measuring the other diagonal it's
17.45.
Note that my caliper can't tell if it's 17.46, just .x0 or .x5.
Can't notice _any_ warping, but it might be there, hard to tell.
Note that this also was a random gear of my collection so it could
just have been that way before boiling.
A reference gear is 17.20 by 17.20 mm though so it might have grown in
the process...
It did not feel different sliding it to an axle either...
I wounder if this works with axles, I'd suppose not since the plastic
feels different.
/Tobbe
http://www.arnesson.nu/lotek/
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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.
Yup :)
> Anyone care to speculate on the physics behind this?
The inner tension of the gear after molding got out?
> TJ
>
> p.s. Thanks Tobbe for sacrificing your gears and axles.
n/p I have a few #6 axles and z16 in my overflow bin...
/Tobbe
http://www.arnesson.nu/lotek/
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Wow ! Interesting results. I would have bet my firstborn that it would
weaken them. Anyone else try this ? I might just to see if Tobbe's result
is a fluke...
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On Wed, 6 Mar 2002 03:31:45 GMT, "Xanthra47" <jmantor@nycap.rr.com>
wrote:
> Wow ! Interesting results. I would have bet my firstborn that it would
> weaken them. Anyone else try this ? I might just to see if Tobbe's result
> is a fluke...
Personally I counted on a big melt and hoped it would not ruin my
kitchen hardware :)
/Tobbe
http://www.arnesson.nu/lotek/
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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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