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LDraw terminology for part anatomy - tom alphin - 2021-09-12

Hi,
Some of you may know me from my book The LEGO Architect or my brickarchtiect.com website.  I'm always looking for ways to simplify the more confusing aspects of our hobby, including my work on the LEGO Brick Labels project.

In order to create the labels, I've needed to craft extremely short descriptions for each part which complement the part image.  (Because the name is always accompanied by the image, I can take some liberties to make the names shorter.)

One of the biggest challenges I've encountered is a semantic one. Different websites (including LEGO.com) use different names for each part, and even for the 'anatomical' elements within a part.  I am in the process of learnign all the names used within the hobby for these connections and anatomy - in the hopes that I can distill the most commonly used terms.

[Image: 2020-10-03%20-%20LEGO%20Storage%20Guide%...irtual.jpg]
Slide showing most of the common connection types in contemporary LEGO parts.

There are several aspects of LEGO part anatomy that I'm curious to hear how they are named within the internals of the LDraw project.

For example:
  • On the underside of a 1x2 brick, there is a rod between the studs to create a gap the right size for a stud to attach.  Is this called a "bar" since it is 2 units wide (in the measurement system used above), or do you have a different term?
  • Hollow Stud - Is there a better term for these hollow studs which accept a bar element?
  • Bar/Clip/Handle - A "handle" has the same diameter as a bar element.  Is there another term for these used within LDraw project?
  • Mini Bar - I  have also seen "prong" as a term for this, such as in the context of relatively new part 68211
  • Click Hinge - I have also heard "indexed hinge" and other terms - is there a common name here?
  • Ball - This is also sometimes described as a constraction hinge - has that term been outmoded by now?
  • Mini Pin - Is that the closest thing we have to a universal name for this non-Technic pin connection?


If there is already a LDraw Part Naming Styleguide, please let me know.  If not, maybe this project can help create one?

Sincerely,
---tom

RE: LDraw terminology for part anatomy - N. W. Perry - 2021-09-13

(2021-09-12, 22:26)tom alphin Wrote: On the underside of a 1x2 brick, there is a rod between the studs to create a gap the right size for a stud to attach.  Is this called a "bar" since it is 2 units wide (in the measurement system used above), or do you have a different term?

In LDraw this is usually called an "understud", although I'm not sure this is a terribly appropriate name for it. It's really the 1x equivalent of a bottom tube, and actually I'd be fine with calling it that since bar and pin already mean other things.

Quote:Hollow Stud - Is there a better term for these hollow studs which accept a bar element?

Perhaps not, although "hollow" often refers only to those studs that are open on top but do not pass through the brick. (A stud that does would be "open", and there are also some that are "blocked".)

RE: LDraw terminology for part anatomy - tom alphin - 2021-09-13

(2021-09-13, 3:08)N. W. Perry Wrote: In LDraw this is usually called an "understud", although I'm not sure this is a terribly appropriate name for it. It's really the 1x equivalent of a bottom tube, and actually I'd be fine with calling it that since bar and pin already mean other things.

"Understud" is a pretty awkward name, but I'm definitely adding it to my glossary of "potential" names for that feature.  "Underbar" would reinforce that it is about 2LU wide (like a Bar element), but that's not a real word either.

maybe even something as simple as "spacer" would be better?


Quote:N. W. Perry
Perhaps not, although "hollow" often refers only to those studs that are open on top but do not pass through the brick. (A stud that does would be "open", and there are also some that are "blocked".)

Very good point.  I have seen both hollow stud and open stud used, and never put much thought to that difference.  It's worth including in my analysis and discussion.  (Both allow you to attach a bar element, so long as it doesn't have a rounded end.)

—Tom

P.S. Feedback on other part nomenclature welcome, too!

RE: LDraw terminology for part anatomy - N. W. Perry - 2021-09-13

(2021-09-13, 5:36)tom alphin Wrote: "Understud" is a pretty awkward name, but I'm definitely adding it to my glossary of "potential" names for that feature.  "Underbar" would reinforce that it is about 2LU wide (like a Bar element), but that's not a real word either.

maybe even something as simple as "spacer" would be better?

If the idea is to refer to connections and function (and it sounds like it is), I don't think comparison to a bar is quite appropriate. Yes, the understud can fit into a hollow stud, but to me a "bar" also suggests the ability to receive a clip, and typically also some amount of room to slide.

One name I forgot about that's often used for this underside feature is "post". That goes well with the equivalently-functioning "tube", and also fits the ability to be inserted into a hollow stud. And the common feature of tubes and posts is, of course, to provide clutch by gripping the spaces between studs, while secondarily allowing an offset construction by inserting a stud into a tube, or a post into a stud.

RE: LDraw terminology for part anatomy - tom alphin - 2021-09-13

(2021-09-13, 12:24)N. W. Perry Wrote: One name I forgot about that's often used for this underside feature is "post". That goes well with the equivalently-functioning "tube", and also fits the ability to be inserted into a hollow stud. And the common feature of tubes and posts is, of course, to provide clutch by gripping the spaces between studs, while secondarily allowing an offset construction by inserting a stud into a tube, or a post into a stud.

"Post" feels like a good term for this - it has an architectural context for "holding stuff up" and is complementary to Tube.  Thanks for the suggestion!

RE: LDraw terminology for part anatomy - Magnus Forsberg - 2021-09-13

How about the Snapstud? Found in the centre of many parts and are used to make turntables of many different sizes.

[Image: stud18a.png]

Top parts: 60474, 87081, 68325, 11213, 74611, 89523, 35442, 35443, 35446
Bottom parts: 27488, 61485, 65146

RE: LDraw terminology for part anatomy - tom alphin - 2021-09-15

(2021-09-13, 21:29)Magnus Forsberg Wrote: How about the Snapstud? Found in the centre of many parts and are used to make turntables of many different sizes.

[Image: stud18a.png]

Top parts: 60474, 87081, 68325, 11213, 74611, 89523, 35442, 35443, 35446
Bottom parts: 27488, 61485, 65146

Great reminder - this is a connection type I need to add to my list.

That said, shouldn't it be called a "snaptube" - it's inner diameter and positioning is certainly that of a tube.