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Hello all,
I have been playing around some Cad software called SolidWorks and would like to
model LEGO bricks. Is there a resource for accurate dimensions of LEGO parts?
Dave
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In lugnet.cad, David VinZant wrote:
> I have been playing around some Cad software called SolidWorks and would like
> to model LEGO bricks. Is there a resource for accurate dimensions of LEGO
> parts?
Hi Dave,
check out the LDraw Specs 1.0.0 at:
http://www.ldraw.org/Article218.html#ldu
An easy way to convert mm in LDUs is Mike Heidemann's prog LDCalc:
http://ldcalc.mikeheide.kilu.de/
Don't miss Marc Klein's website for modeling tips in SW as well as converting SW
data into .dat:
http://marc.klein.free.fr/lego/stl2dat/stl2dat.html
Hope this helps.
w.
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Willy Tschager wrote:
> In lugnet.cad, David VinZant wrote:
> > I have been playing around some Cad software called SolidWorks and would like
> > to model LEGO bricks. Is there a resource for accurate dimensions of LEGO
> > parts?
>
> Hi Dave,
>
> check out the LDraw Specs 1.0.0 at:
>
> http://www.ldraw.org/Article218.html#ldu
>
> An easy way to convert mm in LDUs is Mike Heidemann's prog LDCalc:
>
> http://ldcalc.mikeheide.kilu.de/
>
> Don't miss Marc Klein's website for modeling tips in SW as well as converting SW
> data into .dat:
>
> http://marc.klein.free.fr/lego/stl2dat/stl2dat.html
>
> Hope this helps.
>
> w.
IIRC, *real* Lego parts use Imperial units, so converting to/measuring
using the metric system will involve lots of decimal places.
-Mike
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In lugnet.cad, Michael Horvath wrote:
> Willy Tschager wrote:
> > In lugnet.cad, David VinZant wrote:
> > > I have been playing around some Cad software called SolidWorks and would like
> > > to model LEGO bricks. Is there a resource for accurate dimensions of LEGO
> > > parts?
> >
> > Hi Dave,
> >
> > check out the LDraw Specs 1.0.0 at:
> >
> > http://www.ldraw.org/Article218.html#ldu
> >
> > An easy way to convert mm in LDUs is Mike Heidemann's prog LDCalc:
> >
> > http://ldcalc.mikeheide.kilu.de/
> >
> > Don't miss Marc Klein's website for modeling tips in SW as well as converting SW
> > data into .dat:
> >
> > http://marc.klein.free.fr/lego/stl2dat/stl2dat.html
> >
> > Hope this helps.
> >
> > w.
>
> IIRC, *real* Lego parts use Imperial units, so converting to/measuring
> using the metric system will involve lots of decimal places.
>
> -Mike
Given that Denmark went fully metric in 1912 and that a 1x1 brick is 8mm x 8mm x
9.6mm (stud exclusive) it seems unlikely that imperial will work out better for
you.
Although it does so happen that 8mm is quite close to 5/16inch.
Tim
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>
> Given that Denmark went fully metric in 1912 and that a 1x1 brick is 8mm x 8mm x
> 9.6mm (stud exclusive) it seems unlikely that imperial will work out better for
> you.
>
> Although it does so happen that 8mm is quite close to 5/16inch.
>
> Tim
When I measured a 32 X 32 baseplate it was 10 inches.
From my understanding 1 LDU is about equal to 1/64 inch.
The Lego company though would surely be able to give you precise meaurements.
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In lugnet.cad, Timothy Gould wrote:
> Although it does so happen that 8mm is quite close to 5/16inch.
Huh. I was about to point out that a 48x48 baseplate is 15" per side, but it
turns out it's actually just shy of 15-1/8". Conversion gets you 381mm based on
a 15" baseplate, and 384mm based on an 8mm 1x brick, and that 3mm difference is
just under 1/8".
But yeah, conventional dimensions in the US are that a 2x4 brick is 1-1/4" long,
a stud is 3/16" wide and tiles are 1/8" tall, with 32x and 48x baseplates coming
out at 10" and 15".
There's a lot of really crazy geometric tricks, intentional or not, involved in
LEGO parts (like being able to pinch a plate or tile between two adjacent rows
of studs, or the fact that five plates thickness is exactly equivalent to the
width of a 2x brick), and I have to wonder if it'd be possible to redesign the
LEGO brick in terms of fractional Imperial Standard and still make all of those
tricks work the same way.
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In lugnet.cad, Timothy Gould wrote:
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IIRC, *real* Lego parts use Imperial units, so converting to/measuring
using the metric system will involve lots of decimal places.
-Mike
|
Given that Denmark went fully metric in 1912 and that a 1x1 brick is 8mm x 8mm
x 9.6mm (stud exclusive) it seems unlikely that imperial will work out better
for you.
Although it does so happen that 8mm is quite close to 5/16inch.
Tim
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That’s hardly some freak coincidence. The original 1949 Lego brick was an
unauthorized copy of the Kiddicraft Self-Locking Building Brick, invented by an
Englishman named Hilary Page. When the Christiansens got samples of them from
the British molding company that was producing them, they rounded the original
English dimensions to the closest metric equivalents which preserved the aspect
ratio.(1)
So yes, the Lego brick is officially 8 x 8 x 9.6 mm (ignoring tolerance), but
it’s 5/16 x 5/16 x 3/8 inches in spirit.
Allen
(1) I believe I originally read all this in The World of Lego Toys (1987), but
it is also detailed with references here:
http://news.lugnet.com/general/?n=54084
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In lugnet.cad, Allen Smith wrote:
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That’s hardly some freak coincidence. The original 1949 Lego brick was an
unauthorized copy of the Kiddicraft Self-Locking Building Brick, invented by
an Englishman named Hilary Page.
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I was aware of the Kiddiecraft connection, and that TLC bought all the remaining
rights from them at some point, but I thought the original Automatic Binding
Bricks were a legally licensed copy/variation of the Kiddiecraft bricks. If
they were, in fact, illegal copies, that kinda throws all the aggresive legal
action taken against various clone brands in a weird sort of light.
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In lugnet.cad, Michael Horvath wrote:
<SNIP>
> IIRC, *real* Lego parts use Imperial units, so converting to/measuring
> using the metric system will involve lots of decimal places.
>
> -Mike
Yes, the original design was British, so used imperial units.
Chris
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Michael Horvath wrote:
>
> IIRC, *real* Lego parts use Imperial units, so converting to/measuring
> using the metric system will involve lots of decimal places.
YRW :-)
In a book of LEGO history I read, it was explicitely stated that the
original inch based measures were changed to mm. I don't remember which
year, but it was a long time ago. The distance between two studs is 8 mm.
--
Anders Isaksson, Sweden
BlockCAD: http://web.telia.com/~u16122508/proglego.htm
Gallery: http://web.telia.com/~u16122508/gallery/index.htm
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> In a book of LEGO history I read, it was explicitely stated that the
> original inch based measures were changed to mm. I don't remember which
> year, but it was a long time ago. The distance between two studs is 8 mm.
I tried the experimental approach, built a long line of 23 x Technic beams 16
assembled with plates and measure the total length: 2937mm
With 8mm distance between studs, the theoretical value is 2944mm, error is
-0.23%
With 5/16" distance between studs, the theoretical value is 2921mm, error is
+0.54%
Though we are closer to metric dimensions, I admit my experiment is not
decisive!
But if you look at the names of parts on s@h pick a brick, you see many
dimensions expressed in mm, and a few clearly implies 1stud = 8mm:
Brick Ø16 W. Cross
Parabola Ø16
Parabolic Reflector Ø24x6,4
Parabolic Reflector Ø48
Philo
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Philippe Hurbain wrote:
> With 8mm distance between studs, the theoretical value is 2944mm,
> error is -0.23%
> With 5/16" distance between studs, the theoretical value is 2921mm,
> error is +0.54%
>
> Though we are closer to metric dimensions, I admit my experiment is
> not decisive!
I'm not at liberty to say too much, but I have actually looked at three real
drawings of LEGO parts, and not even TLC seems to be sure what the
dimensions should be - I've seen the distance between two studs dimensioned
as 8 mm on one part and as 8.018 mm on another!
--
Anders Isaksson, Sweden
BlockCAD: http://web.telia.com/~u16122508/proglego.htm
Gallery: http://web.telia.com/~u16122508/gallery/index.htm
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In lugnet.cad, Anders Isaksson wrote:
> I'm not at liberty to say too much, but I have actually looked at three real
> drawings of LEGO parts, and not even TLC seems to be sure what the
> dimensions should be - I've seen the distance between two studs dimensioned
> as 8 mm on one part and as 8.018 mm on another!
That much? Wow. I figured the distance between two studs should be closer to
3mm, since a LEGO tile is (in theory) 3.2mm thick, and it will sorta fit between
two studs. Or were you refering to the center-to-center distance?
Anyways, one thing you have to remember is that the dimensions on a LEGO brick
will be noticably different from the dimensions on a LEGO brick mold. Depending
on the specific shrinkage rate of LEGO-spec ABS, an 8.018 mold dimension could
result in a post-form LEGO brick with an ~8mm dimension. It's been a few years
since I actually had to know the shrink rate of ABS, but one of the sites I
pulled up on a quick search said it ranges from 0.0024in/in to 0.0165in/in.
Going with the former, an 8.018mm mold will produce a 7.9988mm part. The latter
would result in a 7.8879mm part.
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Purple Dave wrote:
> That much? Wow. I figured the distance between two studs should be
> closer to 3mm, since a LEGO tile is (in theory) 3.2mm thick, and it
> will sorta fit between two studs. Or were you refering to the
> center-to-center distance?
Center-to-center, of course. The stud diameters differ by 0.028 between the
drawings too, creating a diff of the gaps of 0.046 (but the length of the
parts are exactly the same).
> Anyways, one thing you have to remember is that the dimensions on a
> LEGO brick will be noticably different from the dimensions on a LEGO
> brick mold. Depending on the specific shrinkage rate of LEGO-spec
> ABS, an 8.018 mold dimension could result in a post-form LEGO brick
> with an ~8mm dimension.
Well, the drawings are of parts, not molds (and the parts are attached).
--
Anders Isaksson, Sweden
BlockCAD: http://web.telia.com/~u16122508/proglego.htm
Gallery: http://web.telia.com/~u16122508/gallery/index.htm
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