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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?
TJ
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In lugnet.technic, Thomas Avery writes:
> 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?
I don't think I'd want to try this. There's a reason that LEGO recommends
washing the parts only in *warm* water: if you used hot water, the plastic
will start to deform. Some instructions specifically state this. For
example: http://www.brickshelf.com/cgi-bin/gallery.cgi?i=131756
--
David Schilling
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In lugnet.technic, David Schilling writes:
<snip>
> if you used hot water, the plastic will start to deform. Some instructions
> specifically state this. For example:
> http://www.brickshelf.com/cgi-bin/gallery.cgi?i=131756
Although this is a good instruction for "general use", I don't think a
single piece by itself will deform. If you handle it carefully (i.e. don't
squeeze it hard by picking it out of the boiling water with tongs), it may
not deform. But then I don't know at what point the ABS will deform under
its own weight, and I'm probably not going to try this :-)
TJ
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In lugnet.technic, Thomas Avery writes:
> In lugnet.technic, David Schilling writes:
> <snip>
> > if you used hot water, the plastic will start to deform. Some instructions
> > specifically state this. For example:
> > http://www.brickshelf.com/cgi-bin/gallery.cgi?i=131756
>
> Although this is a good instruction for "general use", I don't think a
> single piece by itself will deform. If you handle it carefully (i.e. don't
> squeeze it hard by picking it out of the boiling water with tongs), it may
> not deform. But then I don't know at what point the ABS will deform under
> its own weight, and I'm probably not going to try this :-)
>
> TJ
A quick search on Google shows that ABS (Acrylonitrile-butadiene-styrene)
has a melting point of 103-128°C. Since water boils at 100°C, I don't have
any doubt that you would see some deformation by that point.
--
David Schilling
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In lugnet.technic, David Schilling writes:
> In lugnet.technic, Thomas Avery writes:
> > In lugnet.technic, David Schilling writes:
> > <snip>
> > > if you used hot water, the plastic will start to deform. Some instructions
> > > specifically state this. For example:
> > > http://www.brickshelf.com/cgi-bin/gallery.cgi?i=131756
> >
> > Although this is a good instruction for "general use", I don't think a
> > single piece by itself will deform. If you handle it carefully (i.e. don't
> > squeeze it hard by picking it out of the boiling water with tongs), it may
> > not deform. But then I don't know at what point the ABS will deform under
> > its own weight, and I'm probably not going to try this :-)
> >
> > TJ
>
> A quick search on Google shows that ABS (Acrylonitrile-butadiene-styrene)
> has a melting point of 103-128°C. Since water boils at 100°C, I don't have
> any doubt that you would see some deformation by that point.
>
> --
> David Schilling
Oh people people people!!! Stop what you're doing or thinking!!!
http://sparky.i989.net/legop1.htm
Have a boo halfway down the page!!! I mean this was, to date, the most
traumatic event of my life!!!! (well, not really but it makes a great story
when I talk to my LEGO buddies!)
Don't *ever* put LEGO bricks in anything that remotely looks like boiling
water. If bricks can't stand up to it, then fer sure gears won't be able to!!!
You have been warned!
We now return you to your regularly scheduled brick mayhem.
Dave
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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?
>
> TJ
I tried cleaning Lego in boiling water once - it discolours and warps.
(actually, it was Duplo - bought at a garage sale and being sterilized
for the kids, but I have no reason to believe it's made from a
different plastic)
Matthias Jetleb
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In lugnet.technic, Thomas Avery writes:
> 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?
>
> TJ
This sounds like the basic technique for "tempering". You've probably heard
of tempered glass or tempered metal. From what I remember, this just
changes the way the strength is handled in the material. A normal material
bends more instead of breaking. A tempered material won't bend as much,
which gives the impression of it being stronger; however, it is more likely
to shatter than a normal material. Of course, if anyone is a materials
expert (I'm not) then feel free to set me straight here. In any case,
google finds many hits on "tempered glass", but none on "tempered plastic",
and there's probably a reason for that ;-).
+Z+
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Plastic doesn't get stronger under heat-treatment. This type of heat
treatment is used to control the crystallization of metals, and long-chain
polymers like plastic just don't behave like that.
If you need stronger gears, double them. It is the axles that are the weak
point generally, though.
--Jack Gregory
Mark R. Nusekabel <zedot@tampabay.rr.com> wrote in message
news:GsHIJ7.DBI@lugnet.com...
> In lugnet.technic, Thomas Avery writes:
> > 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?
> >
> > TJ
>
> This sounds like the basic technique for "tempering". You've probably heard
> of tempered glass or tempered metal. From what I remember, this just
> changes the way the strength is handled in the material. A normal material
> bends more instead of breaking. A tempered material won't bend as much,
> which gives the impression of it being stronger; however, it is more likely
> to shatter than a normal material. Of course, if anyone is a materials
> expert (I'm not) then feel free to set me straight here. In any case,
> google finds many hits on "tempered glass", but none on "tempered plastic",
> and there's probably a reason for that ;-).
>
> +Z+
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In lugnet.technic, David Schilling writes:
> A quick search on Google shows that ABS (Acrylonitrile-butadiene-styrene)
> has a melting point of 103-128°C. Since water boils at 100°C, I don't have
> any doubt that you would see some deformation by that point.
There are different grades of ABS, each having different mechanical
properties. I found an extensive resource on materials at: http://www.matweb.com
The ABS property data can be found here:
http://www.matweb.com/abspolymer.htm
I picked 3 grades of ABS that seemed likely to be the type(s) that Lego
uses, but I'm not sure:
ABS, Molded
http://www.matweb.com/SpecificMaterial.asp?bassnum=O1100
max service temp in air: 140 - 223 F
mold temperature: 109 - 149 F
processing temperature: 399 - 500 F
ABS, Impact Grade, Molded
http://www.matweb.com/SpecificMaterial.asp?bassnum=O1103
max service temp in air: 167 - 365 F
mold temperature: 111 - 149 F
processing temperature: 410 - 487 F
ABS, Extruded
http://www.matweb.com/SpecificMaterial.asp?bassnum=O1106
max service temp in air: 140 - 212 F
mold temperature: 136 F
processing temperature: 392 - 486 F
I'm not sure what the different terms mean, exactly. I can tell you all
about steel, but nothing about plastic :-)
What I think they indicate (please, someone correct me if I'm wrong) is that
the actual melting point is difficult to pick because of the gradual
softening of the material. I think the actual melting point, or rather the
point at which the material experiences permanent deformation, is dependant
on the applied stresses.
Obviously, there will be a point at which the material deforms under its own
weight, and that is perhaps the classic definition of melting. There will
also be a point at which the material can be safely molded by applied forces
without fracturing the material. This point is perhaps the "mold
temperature". The mold temperature will be much less than the "classic
melting point".
So, what use is this information? Will Lego pieces melt or not in boiling water?
The answer is: NO, they will not melt. However, they WILL permanently deform!
Boiling water (212 F) is much higher than the mold temperatures given above.
Therefore it is possible that the self weight of the material, and also
handling the material in and out of the water, will apply enough stress to
permanently deform (or "remold" if you like) the bricks.
The experiences that others have stated in the thread reinforces this.
TJ
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In lugnet.technic, Jack Gregory writes:
> Plastic doesn't get stronger under heat-treatment. This type of heat
> treatment is used to control the crystallization of metals, and long-chain
> polymers like plastic just don't behave like that.
Yes, this is true.
> If you need stronger gears, double them. It is the axles that are the weak
> point generally, though.
Now that's quite a statement! I got an email yesterday from someone saying
that the axles were the weak point too.
I don't know how you're using your gears, but when something breaks in my
models, it's the gears!
http://www.texbrick.com/ideas/gears/
(see bottom of page)
TJ
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In lugnet.technic, Jason S. Mantor writes:
> The first one you cite is probably the right one for LEGO(R) Bricks.
> They're molded, not extruded and I don't believe they are impact grade.
They're clearly not extruded... that's the kind Plastruct(R) uses.
But if they're just plain molded and not impact grade I am hoping they are
from the higher end of the range. The low end mold temp (and I agree with
Thomas Avery's speculations about what it means although my molding
experience is with aluminium) of 109 scares me... it gets that hot in the
south (or in attics) on a regular basis.
HOWEVER, mold temp MAY mean the temperature you should heat the mold to for
best results... I dunno. But I know that the aluminium targeted molds I saw
were heated to 4-500 degrees Farenheit before the molt was introduced.
Regardless, LEGO(r) will discolor if not actually deform well below boiling
temps, I discolored some LEGO by putting it in a dishwasher.
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The first one you cite is probably the right one for LEGO(R) Bricks.
They're molded, not extruded and I don't believe they are impact grade.
Thomas Avery <thomas.avery@intec-hou.com> wrote in message
news:GsI76v.GED@lugnet.com...
> In lugnet.technic, David Schilling writes:
> > A quick search on Google shows that ABS (Acrylonitrile-butadiene-styrene)
> > has a melting point of 103-128°C. Since water boils at 100°C, I don't have
> > any doubt that you would see some deformation by that point.
>
> There are different grades of ABS, each having different mechanical
> properties. I found an extensive resource on materials at: http://www.matweb.com
>
> The ABS property data can be found here:
> http://www.matweb.com/abspolymer.htm
>
> I picked 3 grades of ABS that seemed likely to be the type(s) that Lego
> uses, but I'm not sure:
>
> ABS, Molded
> http://www.matweb.com/SpecificMaterial.asp?bassnum=O1100
> max service temp in air: 140 - 223 F
> mold temperature: 109 - 149 F
> processing temperature: 399 - 500 F
>
> ABS, Impact Grade, Molded
> http://www.matweb.com/SpecificMaterial.asp?bassnum=O1103
> max service temp in air: 167 - 365 F
> mold temperature: 111 - 149 F
> processing temperature: 410 - 487 F
>
> ABS, Extruded
> http://www.matweb.com/SpecificMaterial.asp?bassnum=O1106
> max service temp in air: 140 - 212 F
> mold temperature: 136 F
> processing temperature: 392 - 486 F
<SNIP>
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In lugnet.technic, Larry Pieniazek writes:
> They're clearly not extruded... that's the kind Plastruct(R) uses.
>
> But if they're just plain molded and not impact grade I am hoping they are
> from the higher end of the range. The low end mold temp (and I agree with
> Thomas Avery's speculations about what it means although my molding
> experience is with aluminium) of 109 scares me... it gets that hot in the
> south (or in attics) on a regular basis.
I measured the temp in my attic last summer and it reached 115 F. Needless
to say I don't keep much up there and definitely not my Lego collection!
ROSCO had a bad "melting" experience:
http://www.brickshelf.com/cgi-bin/gallery.cgi?i=42127
I think this was caused by prolonged exposure to direct sunlight, but I
forgot what he had said about it.
TJ
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In lugnet.technic, Thomas Avery writes:
> In lugnet.technic, Larry Pieniazek writes:
> > They're clearly not extruded... that's the kind Plastruct(R) uses.
> >
> > But if they're just plain molded and not impact grade I am hoping they are
> > from the higher end of the range. The low end mold temp (and I agree with
> > Thomas Avery's speculations about what it means although my molding
> > experience is with aluminium) of 109 scares me... it gets that hot in the
> > south (or in attics) on a regular basis.
>
> I measured the temp in my attic last summer and it reached 115 F. Needless
> to say I don't keep much up there and definitely not my Lego collection!
>
> ROSCO had a bad "melting" experience:
> http://www.brickshelf.com/cgi-bin/gallery.cgi?i=42127
>
> I think this was caused by prolonged exposure to direct sunlight, but I
> forgot what he had said about it.
IIRC, I thought it was from the back shelf of a car... cars with no windows
opened can easily get to 145 or even hotter. (hence the warnings about not
leaving dogs or ferrets or cats or whatever locked in cars on sunny days, it
will kill them)
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If you would just put your bricks in the kitchen oven you would make rapid
progress with this question.
Better yet, obtain a laboratory hot plate with fine temperature control and
put a brick between two slides with a weight on top. Do this at several
temperatures and observe the rate of deformation.
As a crude experiment, chop up a brick and pack it into a small crucible.
You should be able to fuse the particles in a kitchen oven at about 500 F,
but without applied pressure they will be easy to pull apart again.
Remember, experience without theory teaches nothing, so look up those terms
after you've been forbidden to put any more objects in the oven.
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In lugnet.technic, Erik Olson writes:
> If you would just put your bricks in the kitchen oven you would make rapid
> progress with this question.
I am in total agreement with this, including the 'you' (as long as it's not
'me'... advancement of science is fine but I ain't putting my bricks in no
oven thank you)
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In lugnet.technic, Larry Pieniazek writes:
> In lugnet.technic, Erik Olson writes:
> > If you would just put your bricks in the kitchen oven you would make rapid
> > progress with this question.
>
> I am in total agreement with this, including the 'you' (as long as it's not
> 'me'... advancement of science is fine but I ain't putting my bricks in no
> oven thank you)
Yes, I can see how this would help the progress of scientific knowledge, but
realize that technic pieces are hard to come by in the first place these
days.. you cannot walk into your local toystore and pick up a supercar...
that I'll take the pure conjecture that LEGO bricks melt at high
temperatures and not actually research this myself to see if it's true.
For once I'll believe the axiom without trying to prove it myself.
Dave
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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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I have never broken a gear. But then, I am a mechanical engineer; I am nice
to my gears. But I fry a lot of electronics!
My experience is that the torsional stiffness of the axles is the limiting
factor of high-torque designs. I have permanently deformed only one,
though, and I avoid high-torque applications for this reason. There are too
many weak points in LEGO to subject to high forces.
I was surprised when I looked at the gear breakage when it first came up
about a month or so ago. I simply can't imagine how you can do that with a
single axle driving it, but I don't doubt you did. I just think something
else is stressing them besides axles.
--Jack Gregory
Thomas Avery <thomas.avery@intec-hou.com> wrote in message
news:GsI86K.IK2@lugnet.com...
> In lugnet.technic, Jack Gregory writes:
> > Plastic doesn't get stronger under heat-treatment. This type of heat
> > treatment is used to control the crystallization of metals, and long-chain
> > polymers like plastic just don't behave like that.
>
> Yes, this is true.
>
> > If you need stronger gears, double them. It is the axles that are the weak
> > point generally, though.
>
> Now that's quite a statement! I got an email yesterday from someone saying
> that the axles were the weak point too.
>
> I don't know how you're using your gears, but when something breaks in my
> models, it's the gears!
> http://www.texbrick.com/ideas/gears/
> (see bottom of page)
>
> 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?
Thanks,
TJ
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The "service" temperature is the limit at what you should operate it at.
The "mold" temperature is how LOW the mold has to be cooled to get a good
shot.
The "processing" temperature is the temperature the plastic has to be when
it enters the mold.
There are very different materials used in LEGO -- they are not a single
type. The standard bricks may be ABS, but the gears are almost certainly a
different material or grade even of ABS. The trees are certainly different,
the corrugated tubes, etc. Different molding methods require different
blends. I am sure LEGO spends a lot of money on plastic and can get custom
blends for just about anything they want.
I just wish the axles were made of stainless steel.
--Jack Gregory
Thomas Avery <thomas.avery@intec-hou.com> wrote in message
news:GsI76v.GED@lugnet.com...
> In lugnet.technic, David Schilling writes:
> > A quick search on Google shows that ABS (Acrylonitrile-butadiene-styrene)
> > has a melting point of 103-128°C. Since water boils at 100°C, I don't have
> > any doubt that you would see some deformation by that point.
>
> There are different grades of ABS, each having different mechanical
> properties. I found an extensive resource on materials at: http://www.matweb.com
>
> The ABS property data can be found here:
> http://www.matweb.com/abspolymer.htm
>
> I picked 3 grades of ABS that seemed likely to be the type(s) that Lego
> uses, but I'm not sure:
>
> ABS, Molded
> http://www.matweb.com/SpecificMaterial.asp?bassnum=O1100
> max service temp in air: 140 - 223 F
> mold temperature: 109 - 149 F
> processing temperature: 399 - 500 F
>
> ABS, Impact Grade, Molded
> http://www.matweb.com/SpecificMaterial.asp?bassnum=O1103
> max service temp in air: 167 - 365 F
> mold temperature: 111 - 149 F
> processing temperature: 410 - 487 F
>
> ABS, Extruded
> http://www.matweb.com/SpecificMaterial.asp?bassnum=O1106
> max service temp in air: 140 - 212 F
> mold temperature: 136 F
> processing temperature: 392 - 486 F
>
> I'm not sure what the different terms mean, exactly. I can tell you all
> about steel, but nothing about plastic :-)
>
> What I think they indicate (please, someone correct me if I'm wrong) is that
> the actual melting point is difficult to pick because of the gradual
> softening of the material. I think the actual melting point, or rather the
> point at which the material experiences permanent deformation, is dependant
> on the applied stresses.
>
> Obviously, there will be a point at which the material deforms under its own
> weight, and that is perhaps the classic definition of melting. There will
> also be a point at which the material can be safely molded by applied forces
> without fracturing the material. This point is perhaps the "mold
> temperature". The mold temperature will be much less than the "classic
> melting point".
>
> So, what use is this information? Will Lego pieces melt or not in boiling water?
>
> The answer is: NO, they will not melt. However, they WILL permanently deform!
>
> Boiling water (212 F) is much higher than the mold temperatures given above.
> Therefore it is possible that the self weight of the material, and also
> handling the material in and out of the water, will apply enough stress to
> permanently deform (or "remold" if you like) the bricks.
>
> The experiences that others have stated in the thread reinforces this.
>
> 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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In lugnet.technic, Thomas Avery writes:
> In lugnet.technic, Larry Pieniazek writes:
> > They're clearly not extruded... that's the kind Plastruct(R) uses.
> >
> > But if they're just plain molded and not impact grade I am hoping they are
> > from the higher end of the range. The low end mold temp (and I agree with
> > Thomas Avery's speculations about what it means although my molding
> > experience is with aluminium) of 109 scares me... it gets that hot in the
> > south (or in attics) on a regular basis.
>
> I measured the temp in my attic last summer and it reached 115 F. Needless
> to say I don't keep much up there and definitely not my Lego collection!
>
> ROSCO had a bad "melting" experience:
> http://www.brickshelf.com/cgi-bin/gallery.cgi?i=42127
>
> I think this was caused by prolonged exposure to direct sunlight, but I
> forgot what he had said about it.
>
> TJ
That reminds me of a picture I just took in December at Legoland - the Grand
Central Station in Miniland had an amazing bit of damage due to sunlight!
Check it out at http://www.brickshelf.com/cgi-bin/gallery.cgi?i=132159 (big
file - sorry) - look in the bottom right corner of the 'window' where people
are getting on the escalator. First you'll see that the reflection of the
clear plastic window has significantly 'boiled' the bricks below, (okay, I
know it didn't physically boil, but it looks like it!) and you'll also see
that the wall has shrunk to such a point that it detached and bowed.
--
David Schilling
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In lugnet.technic, David Koudys writes:
> Oh people people people!!! Stop what you're doing or thinking!!!
>
> http://sparky.i989.net/legop1.htm
>
> Have a boo halfway down the page!!! I mean this was, to date, the most
> traumatic event of my life!!!! (well, not really but it makes a great story
> when I talk to my LEGO buddies!)
>
> Don't *ever* put LEGO bricks in anything that remotely looks like boiling
> water. If bricks can't stand up to it, then fer sure gears won't be able to!!!
>
> You have been warned!
>
> We now return you to your regularly scheduled brick mayhem.
>
> Dave
So what caused the rash?
Jude
FUT .fun
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In lugnet.technic, Larry Pieniazek writes:
> In lugnet.technic, Jason S. Mantor writes:
> > The first one you cite is probably the right one for LEGO(R) Bricks.
> > They're molded, not extruded and I don't believe they are impact grade.
>
> They're clearly not extruded... that's the kind Plastruct(R) uses.
>
> But if they're just plain molded and not impact grade I am hoping they are
> from the higher end of the range. The low end mold temp (and I agree with
> Thomas Avery's speculations about what it means although my molding
> experience is with aluminium) of 109 scares me... it gets that hot in the
> south (or in attics) on a regular basis.
My guess would be 109C may be more likely - I'd be surprised if they could mold
it at 109F. I'm guessing my bad experience with the heater was well over 109F
(they were quite close to it), and they didn't "flow" anywhere near enough that
I'd expect they'd need for molding.
> HOWEVER, mold temp MAY mean the temperature you should heat the mold to for
> best results... I dunno. But I know that the aluminium targeted molds I saw
> were heated to 4-500 degrees Farenheit before the molt was introduced.
>
> Regardless, LEGO(r) will discolor if not actually deform well below boiling
> temps, I discolored some LEGO by putting it in a dishwasher.
And you can see the discolouration in bricks left outside for prolonged
periods, though this may also be related to light exposure. Just look closely
at the Legoland models 8?)
ROSCO
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Thomas:
Lego uses primarily Bayer Novodur (and apparently to some
extent Bayer Lustran) for its bricks. The exact composition
of the Novodur is of course, like the recipie for Coke, is
top secret, but it is probably closest to Bayer Novodur P2M-V
A datasheet:
http://www.plastics.bayer.com/bayer/services/products/svl/sheet.html?vse=051559
59&item=Novodur%20P2M-V&hlit=0&hcase=0&hsec=0&pid=9
Well since you went to the trouble of looking up all this
information I thought that this data might be of interest
however, in terms of physical properties were probably
splitting hairs
--Jim
In lugnet.technic, Thomas Avery writes:
> In lugnet.technic, David Schilling writes:
> > A quick search on Google shows that ABS (Acrylonitrile-butadiene-styrene)
> > has a melting point of 103-128°C. Since water boils at 100°C, I don't have
> > any doubt that you would see some deformation by that point.
>
> There are different grades of ABS, each having different mechanical
> properties. I found an extensive resource on materials at: http://www.matweb.com
>
> The ABS property data can be found here:
> http://www.matweb.com/abspolymer.htm
>
> I picked 3 grades of ABS that seemed likely to be the type(s) that Lego
> uses, but I'm not sure:
>
> ABS, Molded
> http://www.matweb.com/SpecificMaterial.asp?bassnum=O1100
> max service temp in air: 140 - 223 F
> mold temperature: 109 - 149 F
> processing temperature: 399 - 500 F
>
> ABS, Impact Grade, Molded
> http://www.matweb.com/SpecificMaterial.asp?bassnum=O1103
> max service temp in air: 167 - 365 F
> mold temperature: 111 - 149 F
> processing temperature: 410 - 487 F
>
> ABS, Extruded
> http://www.matweb.com/SpecificMaterial.asp?bassnum=O1106
> max service temp in air: 140 - 212 F
> mold temperature: 136 F
> processing temperature: 392 - 486 F
>
> I'm not sure what the different terms mean, exactly. I can tell you all
> about steel, but nothing about plastic :-)
>
> What I think they indicate (please, someone correct me if I'm wrong) is that
> the actual melting point is difficult to pick because of the gradual
> softening of the material. I think the actual melting point, or rather the
> point at which the material experiences permanent deformation, is dependant
> on the applied stresses.
>
> Obviously, there will be a point at which the material deforms under its own
> weight, and that is perhaps the classic definition of melting. There will
> also be a point at which the material can be safely molded by applied forces
> without fracturing the material. This point is perhaps the "mold
> temperature". The mold temperature will be much less than the "classic
> melting point".
>
> So, what use is this information? Will Lego pieces melt or not in boiling water?
>
> The answer is: NO, they will not melt. However, they WILL permanently deform!
>
> Boiling water (212 F) is much higher than the mold temperatures given above.
> Therefore it is possible that the self weight of the material, and also
> handling the material in and out of the water, will apply enough stress to
> permanently deform (or "remold" if you like) the bricks.
>
> The experiences that others have stated in the thread reinforces this.
>
> TJ
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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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IIRC, ABS is a thermoset plastic. The first time you melt it it's workable
at a relatively low temp and solidifies nicely, but heating it again won't
melt it, only deform it and finally burn it : (
-Xanthra47
Ross Crawford <rcrawford@csi.com> wrote in message
news:GsIupy.Kv9@lugnet.com...
> My guess would be 109C may be more likely - I'd be surprised if they could mold
> it at 109F. I'm guessing my bad experience with the heater was well over 109F
> (they were quite close to it), and they didn't "flow" anywhere near enough that
> I'd expect they'd need for molding.
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In lugnet.technic, Jason S. Mantor writes:
> IIRC, ABS is a thermoset plastic. The first time you melt it it's workable
> at a relatively low temp and solidifies nicely, but heating it again won't
> melt it, only deform it and finally burn it : (
That explains it. And it smells pretty bad too - that's what alerted me when I
had my "accident".
ROSCO
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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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In lugnet.technic, Jason S. Mantor writes:
> IIRC, ABS is a thermoset plastic.
No, it's thermoplastic. But too much heat, or even localized hot spots, can
scorch it and make it unusable.
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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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A Mecha Shower a day keeps the autocannon bullits flying away.
Legomaster
In lugnet.technic, Thomas Avery writes:
> 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?
>
> TJ
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Hello all,
May be I can help a bit with this conversation, I work in plastic
injection moulds, when injecting ABS it becomes stressed cause
of the path it must take to fill the cavity of the mould, when ejected
from the mould, the parts are supposed to fall in a tub of water to
cool them down slowly, but this takes time, and time is money, so
not all of them do this, or do it but there is a lot of parts in the
water, when you do this on your own stove you cool them down
the right way, the best example I can give you is this, take a look
a R/C car parts, I had an RC/10 with a lot of parts made with ABS
once boiled in salted water or water with cloth die in it, the parts
where a little more flexible, the boiling takes the stress out of the
parts, that why they break less once boiled.
excuse the bad english, i'ts not my strong point.
Regards,
Louis Raymond
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Hi Louis, (and all),
I certainly don't dispute your explanation of the casting process, not at all -
in fact I found it interesting to read about the cooling process.
However, all the RC-10-family cars I've ever owned were made of nylon. At least
the bits that weren't aluminum or steel were nylon. This is why these parts
were able to take the boiling process - and can be, as you say, coloured with
fabric dye in the process, if one is so inclined.
As a sidenote, a lot of R/C car parts are now made of some kind of
graphite/plastic composite, and de-stressing can actually do more harm than
good.
Boiling is (er, was; not so much anymore) also used to remove old tires from
rims by breaking down the cyanoacrylate glue used to stick them on in the first
place. Recently though, when I went to do my usual routine on a batch of wheels
(I should've checked what they were made of first), they came out looking like
they belonged in a Salvador Dali painting. A bit of investigation revealed that
the rims were made of ABS plastic.
Ultimately, I would suggest that if anyone wants to try to de-stress a Lego
gear or anything like that, they should first test on a piece they can afford
to lose.
And don't burn yourselves. :)
Cheers,
KMaynes
In lugnet.technic, Louis Raymond writes:
> Hello all,
>
> May be I can help a bit with this conversation, I work in plastic
> injection moulds, when injecting ABS it becomes stressed cause
> of the path it must take to fill the cavity of the mould, when ejected
> from the mould, the parts are supposed to fall in a tub of water to
> cool them down slowly, but this takes time, and time is money, so
> not all of them do this, or do it but there is a lot of parts in the
> water, when you do this on your own stove you cool them down
> the right way, the best example I can give you is this, take a look
> a R/C car parts, I had an RC/10 with a lot of parts made with ABS
> once boiled in salted water or water with cloth die in it, the parts
> where a little more flexible, the boiling takes the stress out of the
> parts, that why they break less once boiled.
>
> excuse the bad english, i'ts not my strong point.
>
> Regards,
>
> Louis Raymond
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In lugnet.technic, Kevin Maynes writes:
<snip>
> Ultimately, I would suggest that if anyone wants to try to de-stress a Lego
> gear or anything like that, they should first test on a piece they can afford
> to lose.
That's what this was all about:
http://news.lugnet.com/technic/?n=6899
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> Ultimately, I would suggest that if anyone wants to try to de-stress a Lego
> gear or anything like that, they should first test on a piece they can afford
> to lose.
Been there, done that :)
I think the gears are made of one kind of plastic (nylon?), axels
another and bricks a third (ABS).
Upon my searching through the Internet I've found a lot of pages about
RC-car-wheel-boiling...
/Tobbe
http://www.arnesson.nu/lotek/
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