Subject:
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Re: Studless building techniques
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Newsgroups:
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lugnet.robotics.edu
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Date:
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Tue, 10 Oct 2006 05:30:04 GMT
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Viewed:
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6449 times
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In lugnet.robotics.edu, Rafe Donahue wrote:
> In lugnet.robotics.edu, Merredith Portsmore wrote:
> <snip>
> >
> > http://www.lego.com/eng/create/technicdesignschool/default.asp
> >
> > Course: Beams & Connectors
> > How LEGO TECHNIC elements work together.
> > Lesson 1: TECHNIC 101
> > Lesson 2: Stability with LEGO TECHNIC
> >
> > Course: Gears
> > TECHNIC on the Move!
> > Lesson 1: Gearing 101
> >
> >
> > Merredith Portsmore
> > Tufts Center for Engineering Educational Outreach
> > Legoengineering.com
>
> Meredith,
>
> Thanks for posting this. It is wonderful first shot at some of these building
> topics.
>
> I am concerned, however, about the Pythagorean triangles on the Stability link.
> The figures show two Pythagorean triangles, namely the 3-4-5 and 6-8-10
> triangles. The figures, unfortunately and arguably incorrectly, show the
> lengths as 4m, 5m, and 6m and 7m, 9m, and 11m. The first course on beams
> defines one 'm' to be the distance between the centers of adjacent holes. As
> such, the figure labels of 4m, 5m, and 6m (and the 7-9-11) are misleading.
> Agreed, there is discussion in the text of there being six holes but the
> distnace is really 5m, but this has all the ingredients to send your typical
> 12-year-old packing. They can learn to count starting at zero or compute the
> distance by subtracting one from the number of holes; we should work hard to
> make sure that the explanations aren't internally inconsistent. The 3-4-5 works
> with the Pythagorean theorem; 4-5-6 does not. Telling them that the distances
> are 4-5-6 in the figure and then doing Pythagoras with 3-4-5 creates, methinks,
> more problems than it solves.
>
> (It might be helpful to show that 5-12-13 and 7-24-25 are Pythagorean triangles,
> too!)
>
> There are actually two further issues; although more minor, they nonetheless
> should be addressed. First, the 'm' used in the figures is a lower-case 'm',
> while in the text it is upper-case 'M'. Some standardization should be used.
> Secondly, if one chooses to use lower-case 'm', one might want to address issues
> in conflict with the SI base unit m, which is meters.
Font issue, I'm sure. The text seems pretty consistent with its use of "M".
> Since we are working with Lego, I might suggest using 'stud' as a unit,
> eventhough it is not part of the SI lexicon, as far as I know! My understanding
> of 'stud' as a unit of measure in the Lego context is that it is equivalent to
> the 'module' defined on your pages.
I wanted to point out here that this was the official LEGO web site you were
looking at, not private pages.
"M" is actually an internal measurement that TLG has used for a long time. It's
now been discussed externally via those pages, so it's much closer to "official"
than either 'stud' or 'LDU' (TLG officially called them studs in English, but
that binds it to a given language).
> Again, thank you for your postings on technic building techniques. I am sure
> that they are of value to many of us who are trying to build better technic
> structures. I just want to make sure that the newbies that read this kind of
> thing are getting a straight scoop. We need to make sure we get the details
> right.
HTH,
-- joshua
Joshua Delahunty
LUGNET Member #3
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Message is in Reply To:
 | | Re: Studless building techniques
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| In lugnet.robotics.edu, Merredith Portsmore wrote: <snip> (...) Meredith, Thanks for posting this. It is wonderful first shot at some of these building topics. I am concerned, however, about the Pythagorean triangles on the Stability link. The (...) (18 years ago, 4-Oct-06, to lugnet.robotics.edu)
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