Lego Element ID - What's the logic?

[DrJB]

I reckon this might belong better under a different forum, though not sure where. My focus is also on Technic so, hopefully this is ok.

If you have some of the recent manuals, there is a Lego ID next to each part in the parts-list. I was 'naively' thinking that some of the digits would correspond to the geometry, and others to the color. This however is NOT the case and identical parts with different colors have totally different IDs.

Has anyone figured out a pattern if one exists or is this totally black science/magic/art ?

Edited February 3, 2015 by DrJB

[Blakbird]

I don't think there is a pattern unless you're Alan Turing. They are just identification numbers.

[dr_spock]

Maybe it is the black magic of the next available number?

[TJoling]

I know for a fact that the first part of the ID is the identificationnumber of the mold used, which explains why elements can have several ID's. A 3 figure section is reserved for the color of the part as well I believe.

[Conchas]

This is an industrial identification system, and there is no need to make it comprehensive in any sense.

It seems to be just a sequential numeric system every time it is decided to bring a new part/color combination into production.

It seems also that once an element stops to be produced and later on it is brought back, a new ID is generated again.

[DrJB]

... the first part of the ID is the identificationnumber of the mold used ...

Interesting. I presume parts are made at many worldwide locations and molds in China or Denmark have different IDs. What happens if the parts of a set are sourced from different locations, because of production capacity or target market? Do the manuals (and IDs) change then?

It seems also that once an element stops to be produced and later on it is brought back, a new ID is generated again ...

What you're saying suggests that the element ID has in it 'hard-coded' a production run, that includes both the mold number and somehow production date. This might help with quality control/tracking ... interesting.

Edited February 3, 2015 by DrJB

[jantjeuh]

See below.

Edited February 3, 2015 by jantjeuh

[Conchas]

Where did you get that? I think that's nonsense. The mold is identified by the Design ID, not by the Element ID. The Element ID is a unique number for the combination of a Design ID and a colour (usually).

In fact this is not correct! Just take a look in a series of elements base on the same design.

For example: http://www.bricklink...temNo=43857&v=2

What you're saying suggests that the element ID has in it 'hard-coded' a production run, that includes both the mold number and somehow production date. This might help with quality control/tracking ... interesting.

That's not the case also.

Although some parts have an extra code engraved, that identifies the year and production week, like the large linear actuators for example. But there are also other examples.

[DrJB]

The plot (and mystery) thickens ...

Would be interesting to take all my manuals/instructions that had the large linear actuator, record those IDs, and see what one can learn.

Edited February 3, 2015 by DrJB

[jantjeuh]

I know for a fact that the first part of the ID is the identificationnumber of the mold used, which explains why elements can have several ID's. A 3 figure section is reserved for the color of the part as well I believe.

Where did you get that? I think that's nonsense. The mold and print combination is identified by the Design ID, not by the Element ID. The Element ID is a (usually) unique number for the combination of a Design ID and a colour. The Decoration ID (not an official name), which sometimes can be derived from the 'official' description of the part, identifies the print, if present. The base mold is not identified by the Design ID or Element ID at all, if the part is printed. Sometimes when a mold is slightly updated (or the mold is worn out and replaced, I guess), a new Element ID can be issued for an existing Design ID and colour combination. The Design ID might also be updated then.

As an example, consider this part:

Here's its associated Element ID information:

Element ID 6101927
Design ID 19748
Description ROUND PLATE Ø32X6.4 "NO.17"
Color Description SAND YELLOW

In this case, the Element ID is 6101927, the Design ID is 19748, the base mold's (3960) Design ID is 3960, and the 'Decoration ID' is 17.

Edited February 3, 2015 by jantjeuh

[Conchas]

In fact I meant not your sentence but the sentence that you have quoted in your answer.

By mistake I should have deleted that part of quote, which made it a bit misleading.

[jantjeuh]

As for an example of different Design IDs being used for the same mold, consider 3960 again. TLG have used Design IDs 3960, 30065 and 56641 for this part. 3960 is for the 'regular' (ABS) version, 30065 for the transparent (different kind of plastic) version, and 56641 for the metallic silver version.

Also, when it comes to Element IDs you shouldn't trust BrickLink, they often map them to incorrect colours

[Rishab N]

I think most of the angled connectors have similar numbers except one of them(32016,32014 etc.)

[DrJB]

Also, when it comes to Element IDs you shouldn't trust BrickLink, they often map them to incorrect colours

Agreed, I've seen enough 'errors' and 'mis-statements' that now I take BL's info with a grain of salt.

[jantjeuh]

BrickLink is very inaccurate when it comes to mold differences as well, unfortunately. BL's main problem is that they cannot easily update the catalogue since so many sellers depend on it for their shop inventories.

[Karle]

Well now! That's as clear as mud.

[Dafgek81]

Do BL numbers correspont with the TLG design ID numbers?

[DrJB]

Do BL numbers correspont with the TLG design ID numbers?

No, not at all. On many lego parts, if you look closely, you'll see very small numbers, either a series of 4 or 5 digits. That's the number referenced in BrickLink, Peeron and LDD. As for the TLG Design Element ID numbers, I've seen those only on Lego manuals and their website.

The other question is: On many small parts, there are no numbers molded-in, e.g the many flex axles and ribbed hoses. In this case, it is not clear (to me) where the BrickLink numbers/designation comes from.

Incidentally, the site rebrickable, when you call in a given part, gives you the multiple designations per BL, Peeron, and so on. That site (owner is a member on here) is the most 'comprehensive' source out there.

Edit: Wrote Design ID, but meant Element ID.

Just so we're all clear:

Design ID - 4/5 digits number you can see (very small) on many/most lego parts

Element ID - You can see this only in recent sets, in the manual, with the list of elements

Edited February 8, 2015 by DrJB

[jantjeuh]

Do BL numbers correspont with the TLG design ID numbers?

BrickLink's (and Rebrickable's) numbering scheme for newer parts (since about 2006, when TLG started making the Design IDs public) are indeed based on TLG's Design IDs. Not sure what DrJB is on about, I think he's confusing Design IDs and Element IDs. BrickLink's Decoration IDs (i.e., the 1234pb5678 bit) for printed parts are more or less simply a sequential number, and not based on TLG's Decoration IDs (which Rebrickable does use in their part numbers). The reason for that is that BrickLink chose to use the same numbering scheme for both printed parts (which have Decoration IDs, usually) and stickered parts (which are counterparts, and are assembled by the end user). A mistake, IMO.

As mentioned above, at Rebrickable we try to use TLG's 'official' numbers and colors as much as possible. For instance, we always try to use their Design IDs, unless a new Design ID is issued for an existing mold (we keep the old number for legacy reasons), or in the case of printed parts (we instead use the Design ID of the base mold, suffixed with the Decoration ID, in the form 1234pr5678 for printed parts, and in the form 1234pat5678 for patterned/co-injected parts).

As an aside, when it comes to for instance leg assemblies, TLG assigns colors based on the left leg of the assembly. BrickLink on the other hand, assigns colors based on the color of the hips. We at Rebrickable follow TLG and also base the color of the assembly on the color of the left leg.

Edited February 8, 2015 by jantjeuh

[DrJB]

... Not sure what DrJB is on about, I think he's confusing Design IDs and Element IDs ...

Not confusing, but mis-wrote. Incidentally, this site is about Design ID (What you see in recent manuals). The Element ID (Bricklink/LDD/Peeron/...) is typically molded in, and is not the source of any confusion.

Question: What is a left/right Hip/LEG assembly?

Edited February 8, 2015 by DrJB

[jantjeuh]

Incidentally, this site is about Design ID (What you see in recent manuals). The Element ID (Bricklink/LDD/Peeron/...) is typically molded in, and is not the source of any confusion.

That should be exactly the other way around Design IDs are molded in, Element IDs are listed in the manual.

[DrJB]

That should be exactly the other way around Design IDs are molded in, Element IDs are listed in the manual.

lol ... now we're back to square one, It's all about Terminology of course. I stand corrected!

Per shop.lego.com, the part shown below in TransClear color has two designations:

Element ID: 3005740 Design ID: 30057

You'd notice that, and back to the 'origins' of this thread, that in this specific case Element ID = Design ID + 40

This pattern however is not always the same for other parts/colors. For Example, the two parts below

Element ID: 4107066 Design ID: 32013

Element ID: 4107085 Design ID: 32013

[jantjeuh]

As indicated here, 30057 is the Design ID used for the transparent colors of the 1 x 1 round plate part. Other Design IDs used are 6141, 44325, 51809 and 15570 (the latter three for metallic/chrome silver colors). Indeed there are several Element IDs associated with the 30057 Design ID that also start with '30057' (but not all), but for the other Design IDs of this part (and for the vast majority of other parts) this is not the case.

Edited February 8, 2015 by jantjeuh

[DrJB]

Of all the people (outside of TLG), it looks like you know the most about this topic. Glad to have YOU on board

The question now is 'Why?'. Is there a 'relationship' between mold dimensions and colors? In a current/other thread, some people have suggested that because different colors (and type) of plastic have different shrinkage (after cooling), those different colors/plastics would require different molds. Could it be that Colors A/B/C use Mold X1 and colors E/F/G use Mold X2?

Edited February 8, 2015 by DrJB

[jantjeuh]

Different production processes or different types of plastic are used for different colors.