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In lugnet.loc.uk, Simon Bennett writes:
> Dear All
>
> There was a letter in last week's New Civil Engineer which I shall reproduce
> for you:
>
> "I support the suggestion made by your correspondent (nCE 7 June) that
> Meccano be adopted by schools to assist in the study of construction.
> Unfortunately it is my experience that teachers expect children to construct
> things using Lego, which although it has some merits, is absolutely hopeless
> for modelling structures or demonstrating mechanics."
>
> The writer provided his address so after a few hours to calm down I thought
> we might like to respond to this.
>
> What do you think?
>
> Psi
I think he's right.
I have a BS degree in Aerospace Engineering, and took many courses in
engineering mechanics. The simplifications used in engineering mechanies are
better modeled by Meccano (or Erector sets) than in Lego. Techniq is better
than the bricks, but still not as good.
Some of the simplifications are used to avoid nondeterminate equations (ie.
four equations and six variables). One example is that many joints are
considered to be only constrained vertically and horizontally, not
rotationally. If you were to model a truss with four elements meeting (which
is most of the truss), you would have to use an axle in Techniq and end up
with a four wide section, it's much easier to model in Meccano. Plus, if
your axle went through a cross shaped hole, you have a resistance to any
torque and your equations would be much harder.
Another simplification is that only one end of structure is fixed, the other
is free to move back and forth (again, this simplifies the equations
immensely without much of a change in the answer). With bricks, you'd need
tiles to properly model that.
Another simplification is that materials are rigid and do not deform.
Deformations change your structure and make your equations much more
difficult. Again, Meccano should be better than ABS here.
Finally, Techniq is too limiting geometrically. There are configurations
that are hard to pull off (ie. a seven cylinger rotary airplane engine) in
TEchniq that can be more easily modeled in Meccano.
Hope this clarifies things,
George
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In lugnet.loc.uk, George Haberberger writes:
>
> I think he's right.
>
> I have a BS degree in Aerospace Engineering, and took many courses in
> engineering mechanics. The simplifications used in engineering mechanies are
> better modeled by Meccano (or Erector sets) than in Lego. Techniq is better
> than the bricks, but still not as good.
>
> Some of the simplifications are used to avoid nondeterminate equations (ie.
> four equations and six variables). One example is that many joints are
> considered to be only constrained vertically and horizontally, not
> rotationally. If you were to model a truss with four elements meeting (which
> is most of the truss), you would have to use an axle in Techniq and end up
> with a four wide section, it's much easier to model in Meccano. Plus, if
> your axle went through a cross shaped hole, you have a resistance to any
> torque and your equations would be much harder.
>
> Another simplification is that only one end of structure is fixed, the other
> is free to move back and forth (again, this simplifies the equations
> immensely without much of a change in the answer). With bricks, you'd need
> tiles to properly model that.
>
> Another simplification is that materials are rigid and do not deform.
> Deformations change your structure and make your equations much more
> difficult. Again, Meccano should be better than ABS here.
>
> Finally, Techniq is too limiting geometrically. There are configurations
> that are hard to pull off (ie. a seven cylinger rotary airplane engine) in
> TEchniq that can be more easily modeled in Meccano.
>
> Hope this clarifies things,
>
> George
Thanks George,
I agree with much of this and am glad someone has taken the opposite view.
BUT...
From the context of the original letter I think the author is referring to
education well below undergraduate level where analysis will not be used in
such depth and the issues of fixity are therefore not relevant. I agree
with what Jason Railton said in his post about the way in which children are
taught and I still believe Lego is better for this application.
Do you think I ought not to send the letter or do you have any changes you
would suggest?
Psi
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In lugnet.loc.uk, Simon Bennett writes:
> Thanks George,
>
> I agree with much of this and am glad someone has taken the opposite view.
> BUT...
>
> From the context of the original letter I think the author is referring to
> education well below undergraduate level where analysis will not be used in
> such depth and the issues of fixity are therefore not relevant. I agree
> with what Jason Railton said in his post about the way in which children are
> taught and I still believe Lego is better for this application.
>
> Do you think I ought not to send the letter or do you have any changes you
> would suggest?
>
> Psi
Reading your letter, I think you should send it, my remarks are better
suited for an undergraduate class, or perhaps a high level high school class.
I don't have any Civil Engineering background (other than that which would
have been common to my degree) but I'm still not totally sold on bricks for
modeling construction. Techniq would work very well for kids for modelling
mechanics, and the gears should work very well, too.
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In lugnet.loc.uk, George Haberberger writes:
> Reading your letter, I think you should send it, my remarks are better
> suited for an undergraduate class, or perhaps a high level high school class.
>
> I don't have any Civil Engineering background (other than that which would
> have been common to my degree) but I'm still not totally sold on bricks for
> modeling construction. Techniq would work very well for kids for modelling
> mechanics, and the gears should work very well, too.
I have now sent the letter. I didn't change it that much and it's still
very long but I wanted to get it out there before I got cold feet about
sending it at all!
The text was:
"Dear Sir
I would like to take the opportunity to respond to Christopher Ward’s letter
(NCE 28 June) and his comments regarding the relative merits of Meccano and
Lego. I can only assume that Mr Ward is unaware of the elements available
in Lego’s Technic and Dacta product lines, particularly the Technic beam and
connector pin or axle system which enables large trusses to be built very
quickly. A full reference guide to the elements available in Technic can be
found at Jim Hughes’ excellent website Technica
http://w3.one.net/~hughesj/technica/technica.html
I am a member of the online Lego community Lugnet (www.lugnet.com). Mr
Ward’s letter has led to some interesting discussions among the world’s Lego
enthusiasts (which you can read starting here:
http://news.lugnet.com/loc/uk/?n=6806 ) and we would like to offer some
examples of the functionality of Lego.
I am unsure whether Mr Ward was advocating Meccano as a structural or a
mechanical engineering modelling tool so I’ll address the Civils issues
first. I was taught that there are four main materials used in
construction: Timber, Concrete, Masonry and Steel. Clearly neither system
would be good for modelling timber construction, concrete is similarly
beyond either. Lego is far better at masonry because its basic elements are
bricks and I would strongly contend that there is little to choose between
the two as far as modelling steel construction is concerned. Pictures of
Lego structures which demonstrate this can be found at
www.lugnet.com/~469/projects/archbr (Ross Crawford’s arch bridge) and
http://tanyatj.home.texas.net/tjscreations/creations/bridge_straight/
(Thomas Avery’s bridges).
As far as mechanical engineering is concerned Meccano may have had an
advantage prior to the late 1970s but these days Lego has a much wider range
of gears and other mechanical elements than Meccano, including
differentials, shock absorbers, pneumatic pumps and cylinders, gearboxes,
cams and flexible drive shafts. Examples of models which show good use of
mechanical principles are Jennifer Clark’s trucks and construction machinery
(www.telepresence.strath.ac.uk/jen/lego/) and Dennis Bosman’s mobile cranes:
(www.geocities.com/MotorCity/Highway/2290/bmnr04.html).
Lego also has an educational theme called Dacta, which is only available to
educational establishments (though if anyone is interested it can be bought
at Legoland or by mail order from www.pitsco-legodacta.com). Dacta includes
solar cells, capacitors and other electronic and mechanical parts along with
teaching guides and other support to use Lego in the classroom. I do not
believe anything so comprehensive has ever been provided by Meccano.
In an educational environment Lego has distinct advantages, firstly and most
importantly it is quick to put together and take apart and secondly it is
easier for a child to pick up the idioms necessary for successful
construction. (Professor Fred Martin of MIT has written a useful guide which
explains these: ftp://cherupakha.media.mit.edu/pub/people/fredm/artoflego.pdf).
For these reasons I feel that Lego is a better educational tool than Meccano.
To summarise I am a Civil Engineer in large measure thanks to Lego and I
cannot allow such a slight to the Toy of the 20th Century to go unchallenged.
Simon Bennett (G)"
I hope that it reflects most people's comments and you are all happy with it.
Psi
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In lugnet.loc.uk, Simon Bennett writes:
<snip>
> I have now sent the letter. I didn't change it that much and it's still
> very long but I wanted to get it out there before I got cold feet about
> sending it at all!
<snip>
You rock. Very nicely done. I think I speak for a number of people when I
say "thanks for doing this, well done!"
++Lar
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In lugnet.loc.uk, Larry Pieniazek writes:
> You rock. Very nicely done. I think I speak for a number of people when I
> say "thanks for doing this, well done!"
>
> ++Lar
Cheers Larry, I've got a nice warm Lugnetty 'included' feeling now! All we
have to do now is just sit back and watch New Civil Engineer not publish it!
Psi
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Subject:
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Re: New Civil Engineer letter
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Newsgroups:
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lugnet.robotics
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Date:
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Sat, 7 Jul 2001 03:44:07 GMT
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Original-From:
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Steve Baker <sjbaker1@airmail.#nospam#net>
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Reply-To:
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sjbaker1@+saynotospam+airmail.net
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Viewed:
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1533 times
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Larry Pieniazek wrote:
>
> In lugnet.loc.uk, Simon Bennett writes:
>
> <snip>
>
> > I have now sent the letter. I didn't change it that much and it's still
> > very long but I wanted to get it out there before I got cold feet about
> > sending it at all!
>
> <snip>
>
> You rock. Very nicely done. I think I speak for a number of people when I
> say "thanks for doing this, well done!"
Yes - nicely said.
One difference that *is* significant from an educational standpoint (IMHO)
is the use of tools. Meccano really does require you to use a screwdriver
and spanner (aka wrench)...where Lego doesn't really require tools at all
(except maybe the brick separator). You might regard that as an advantage
*or* a disadvantage from an educational standpoint...I'm not sure which!
However, the way Lego eases a child gently through the 'stacking blocks'
phase through Duplo, Lego *bricks*, Technics and ultimately, Mindstorms is
unrivalled. There is no other system that can span from 1yr old to 99yrs+
with a single set of compatible components.
My kid was raised on Lego *and* Meccano *and* Lincoln Logs *and* Knex
*and* Construx *and* Girder-and-Panel *and* balsa-wood+glue *and* Anatomics
(you build dinosaur skeletons from a bunch of 'bones' that snap together
using ball-and-socket joints) *and* Wizzard Wandz *and* <some German system
that lets you build full-sized climbing frames from two foot long sections
of plastic pipework - and comes with a 1/10th scale version of all the parts
so you can plan your work on a more reasonable scale!>.
There have been *many* others.
At age 10, he is just starting in on pressure-treated-lumber-and-coach-bolts,
Linux, C++ programming and my wife's 1972 VW bug!
Lego is undoubtedly the most enduring and most flexible of those systems
- but they all have their place and to pick a *single* building system
for your kids would be to miss out on a wide range of experiences.
----------------------------- Steve Baker -------------------------------
HomeMail : <sjbaker1@airmail.net> WorkMail: <sjbaker@link.com>
HomePage : http://web2.airmail.net/sjbaker1
Projects : http://plib.sf.net http://tuxaqfh.sf.net http://tuxkart.sf.net
http://agtoys.sf.net http://prettypoly.sf.net
http://freeglut.sf.net http://toobular.sf.net
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Steve wrote:
> My kid was raised on Lego *and* Meccano *and* Lincoln Logs *and* Knex
> *and* Construx *and* Girder-and-Panel *and* balsa-wood+glue *and*
> Anatomics
> (you build dinosaur skeletons from a bunch of 'bones' that snap together
> using ball-and-socket joints) *and* Wizzard Wandz *and* <some
> German system
> that lets you build full-sized climbing frames from two foot long sections
> of plastic pipework - and comes with a 1/10th scale version of
> all the parts
> so you can plan your work on a more reasonable scale!>.
>
> There have been *many* others.
>
> At age 10, he is just starting in on
> pressure-treated-lumber-and-coach-bolts,
> Linux, C++ programming and my wife's 1972 VW bug!
Ummm, can you adopt older (39 yrs) kids like myself? :-)
Cheers, Ralph
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In lugnet.loc.uk, Simon Bennett writes:
> In lugnet.loc.uk, George Haberberger writes:
> > Reading your letter, I think you should send it, my remarks are better
> > suited for an undergraduate class, or perhaps a high level high school class.
> >
> > I don't have any Civil Engineering background (other than that which would
> > have been common to my degree) but I'm still not totally sold on bricks for
> > modeling construction. Techniq would work very well for kids for modelling
> > mechanics, and the gears should work very well, too.
>
> I have now sent the letter. I didn't change it that much and it's still
> very long but I wanted to get it out there before I got cold feet about
> sending it at all!
>
> The text was:
[text snipped]
> I hope that it reflects most people's comments and you are all happy with it.
Well, I didn't comment yet in this thread, because I'm not an engineer or a
teacher (though I did start in engineering at uni), and I hadn't really thought
much about it. I did have one small Meccano set when I was a kid, but it didn't
take me long to lose all those darn nuts & bolts, so I never really did
anything with it.
But having read your letter, I think it does a pretty good comparison. I
wonder, though how "juniorisation" is going to affect that comparison, and what
(if anything) Meccano is planning in the way of new directions? Best keep on
your toes, TLC!!!
(Oh, and it's pretty cool to get a mention in such an auspicious letter,
thanks!)
ROSCO
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In lugnet.loc.uk, Ross Crawford writes:
> Well, I didn't comment yet in this thread, because I'm not an engineer or a
> teacher (though I did start in engineering at uni), and I hadn't really thought
> much about it. I did have one small Meccano set when I was a kid, but it didn't
> take me long to lose all those darn nuts & bolts, so I never really did
> anything with it.
>
> But having read your letter, I think it does a pretty good comparison. I
> wonder, though how "juniorisation" is going to affect that comparison, and what
> (if anything) Meccano is planning in the way of new directions? Best keep on
> your toes, TLC!!!
>
> (Oh, and it's pretty cool to get a mention in such an auspicious letter,
> thanks!)
>
> ROSCO
Crikey ROSCO, all I did was write a letter, you built the bridge!
Psi
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"Ross Crawford" <rcrawford@csi.com> skrev i meddelandet
news:GG1utI.nE@lugnet.com...
> [...]
> I wonder, though how "juniorisation" is going to affect that comparison, and • what
> (if anything) Meccano is planning in the way of new directions?
Meccano is also juniorizing, and putting out more "models" and less basic
sets.
--
Anders Isaksson, Sweden
BlockCAD: http://user.tninet.se/~hbh828t/proglego.htm
Gallery: http://user.tninet.se/~hbh828t/gallery/index.htm
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In lugnet.loc.uk, Simon Bennett writes:
> I have now sent the letter. I didn't change it that much and it's still
> very long but I wanted to get it out there before I got cold feet about
> sending it at all!
That's great, Simon! I hope all of our comments and input were constructive
enough. Your final revision of the letter was not too long, hit some very
important points, and certainly made a good argument that Lego is a better
"building system".
It's now up to the reader to take advantage of the information presented in
the letter and really learn what Lego is about.
Let us know what happens and if you get any response.
thanks,
T. J.
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In lugnet.loc.uk, George Haberberger writes:
> Some of the simplifications are used to avoid nondeterminate equations (ie.
> four equations and six variables). One example is that many joints are
> considered to be only constrained vertically and horizontally, not
> rotationally. If you were to model a truss with four elements meeting (which
> is most of the truss), you would have to use an axle in Techniq and end up
> with a four wide section, it's much easier to model in Meccano.
True, you do end up with a 4-wide eccentric connection. However, gusset
plates can be used instead of trying to line up 4 members on a common pin.
This can be accomplished by using extra beams or other members at the joint.
You may not end up with a perfectly non-eccentric joint, but you certainly
can reduce the width.
> Plus, if
> your axle went through a cross shaped hole, you have a resistance to any
> torque and your equations would be much harder.
Nothing can model a frictionless pin, despite the assumption made for a
truss. And besides, making trusses with real pinned connections is rarely
done anymore. Most of the members are "I" or box sections connected with
gusset plates. The connection is fixed, each member is rigidly fixed to
another. If tubes are used, they are all coped and then welded together.
> Another simplification is that only one end of structure is fixed, the other
> is free to move back and forth (again, this simplifies the equations
> immensely without much of a change in the answer). With bricks, you'd need
> tiles to properly model that.
And Lego offers tiles, many tiles.
> Another simplification is that materials are rigid and do not deform.
> Deformations change your structure and make your equations much more
> difficult.
Only if the deformations significantly alter the geometry of the structure.
Most elastic deformations are small and are neglected in any calculations.
If you want your structure to survive and not destroy the "building system"
you've invested in, you'd better not overload it.
> Again, Meccano should be better than ABS here.
Well, if you're going to build something and perform calculations to model
your models reactions, then steel or aluminum parts would be better. ABS is
a non-isotropic material. It has a different modulus of elasticity in
different directions. The modulus of elasticiy, E, of ABS in flexure is 2.07
GPa, and the E in tension is 190 GPa (Ref. Machinery's Handbook, 25th Edt.).
Your calcuations assume that the material is isotropic (i.e. it behaves the
same way in all directions- the modulus of elasticity and Poisson's ratio
are constant). Although steel and aluminum can sometimes be non-isotropic,
it is safe to assume they are isotropic (at least for simple calculations).
> Finally, Techniq is too limiting geometrically. There are configurations
> that are hard to pull off (ie. a seven cylinger rotary airplane engine) in
> TEchniq that can be more easily modeled in Meccano.
I agree. However, you really have to sit and think about this one. I'm sure
there are many things Meccano can do that Lego can't. However, I have an
idea that there are many more things that Lego can do that Meccano can't
(pneumatics, robotics, sophisticated electronics, etc.).
> Hope this clarifies things,
To ultimatly decide which system is best, you have to really consider the
purpose of having a "building system" in the first place:
1. Do you want something that is quick and easy to use, that will be able to
demonstrate a wide range of mechanical, structural, and electrical systems?
2. Do you want a realistic system capable of providing engineers with
materials identical to real-life situations and to perform calculations in
conjunction with experiment?
If you desire the first, then Lego is the choice. I think it has an
excellent selection of parts that can be used to model just about anything.
It's a convenient and easy to use system that requires no tools for assembly
and disassembly.
If the second is desired, I think you'd be better off with a home-build
system (i.e. stock up on plate, angles, tees, channels, tubes, etc. as well
as bolts and welding equipment; don't forget all the tools required for
assembly). In order to model more "mechanical" systems, you'll have to
purchase hydraulic and electronic components that can be very expensive
(relative to Lego).
To sum this up, the perfect building system would be just a scaled-down
version of the real thing. An ideal building system capable of demonstrating
real-life systems would be one that is easily obtainable, is relatively
inexpensive, provided a good inventory of parts, and could be used with
little effort. I think Lego fits the "ideal system".
T. J.
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