LDraw.org Discussion Forums

Hi all,


Tiny ball joints. by Genghis Don, on Flickr

I'm so excited about the new ball and socket parts I made them for LDraw today so LDraw users can started with them early.


Ball and socket by gambort, on Flickr

Tim

Great new parts indeed! See also http://www.newelementary.com/2013/07/mix...-page.html
Note: socket is not BFCed but carries a BFC CCW tag. This may cause some sections disappear depending on viewer settings. It should either be really BFCed, or use a BFC NOCERTIFY tag...

Should hopefully be fixed now (replaced the attachment). I ran into the BFC/no-lighting problem in LDView and didn't notice the errors until I got red/green working again.

Tim

Now Brickset shows slightly other shapes ...

Brickset News

Design-ID 14417


Design-ID 14419


Design-ID 14418


Design-ID 14704

Thanks for the numbers. All parts are now up on the part tracker.

Tim

Tim I had to hold the parts because of the name.

Small ball is much to vague for me. We can go with ball and size mentioned or if the size fits - with Towball like in the past.

The primitives should be named: "Towball with shaft" and "Towball with reduced shaft"

Same for the sockets: we have the old style that it never made to a primitive and the new one. So a good name might be "Towball-Socket".

This naming and the use of primitives in these kind of parts are important in my eyes, as they clearly connection point that can be used later on in connectivity support of any application.

All vintage parts like 3731, 3184, 2508 and maybe 2908, 6540a and a lot more needs to be updated to use the same "ball" primitive. There is a lot to do if we are going to make it good IMHO.

Hi Mike,

No problem with the hold. I had hoped the new names were OK since this discussion had been here for a while, but I totally see your point.

I don't like "towball" because it is too restrictive (names original function, not form) now that the new parts are part of a full friction joint system (with the old parts backwards-compatible). I think there are also slight differences between the old and new ball designs but would need to get ahold of the new parts to check.

Let's try to come up with a standard here:

I favour

ball (8LDU) - like in the new parts and probably future remouldings of the older parts
ball (8LDU) no indent - like in the old parts
socket (8LDU) with friction - like in the new parts
socket (8LDU) without friction type X - like in the old parts (there are several varieties) and possibly future parts


I plan to start working on the older parts soon but hope other people will jump on them too.

Tim

Also - we might need a new section in the primitive reference

We will need for sure to have such a new section for this connections.

I am perfectly with you regarding the description you made.

As there are also currently the "ball joint" connection for f.e. Bionicle and Hero parts we need a strong difference to those.

In my personal experience it would not matter if we call it "Towball" also in the future, as I have learned to know what "Towball" means. But you are right, after looking into the dictionary now I know what "Towball" is
If we can get a name to this connection the benefit would be to have it easier to search for matching parts. But that should be only the second aim.

How about:

ball joint (8LDU) *
socket joint (8LDU) *


which ties it in conceptually to the larger versions, but makes it clear they are the smaller 8LDU sort.

Tim

PS. The builder in me loves when LEGO start a new clever part range, the part author in me less so

Hmmm...

What about simply this:
The type of connection is called joint-8 and in front whether it's male (ball) or female (socket)

ball joint-8 *
socket joint-8 *

I like that.

What about primitive names?

j8ball*.dat
j8sock*.dat

Tim

Hi Tim, could you perhaps wait a minute.

I had already all of these part prepared, and have sent them to Admin.

I've made use of the new primitive cyl4sph8.dat in all of these files.
2508, 2736, 3184, 3614, 3731, 4089, 6571, 6572, 6574, 6628, 41895

I've also included one new primitive 35cyl8sph.dat
That one is used in the updated version of 32186.
The subfile s\32186s01 is also reworked.

It would be OK with me, if they instead use the ball-primitive.

We are free and do not need to cut it this way i think.

joint-8-balla.dat - Ball Joint-8 with Straight Bar
joint-8-ballb.dat - Ball Joint-8 with Straight Bar with groove (not sure how to describe the difference)
joint-8-socketa.dat - Socket Joint-8 with 4 clamps type 1 (not sure how to describe the difference)
joint-8-socketb.dat - Socket Joint-8 with 4 clamps type 2 (not sure how to describe the difference)
joint-8-socketc.dat - Socket Joint-8 with 2 clamps (not sure how to describe the difference)

I hope I catched all possibilities

That sounds good Still work that needs to be done, but if we have those parts on the pt it is easier to have an overview.

I just asked LDFind for the word Towball and I got a list with 28 parts, where 1 of those are only listed because of the keywords: Technic Liftarm 2 x 7 with 2 Ball Joints
Name: 32173.dat

All other parts are related to this kind of connection and needs to be considered.

Hi Michael,

We definitely need to specify with or without friction in the socket parts. The new type (pictured in this thread) serve a very different purpose to the old type.

e.g.

joint-8-balla.dat - Ball Joint-8 with Straight Bar -- e.g. old parts
joint-8-ballb.dat - Ball Joint-8 with Straight Bar with groove -- e.g. new parts

joint-8-socket-freea.dat - Free Socket Joint-8 Round -- e.g. 3183.dat
joint-8-socket-freeb.dat - Free Socket Joint-8 Square-- e.g. 98263.dat
joint-8-socket-frica.dat - Friction Socket Joint-8 -- e.g. new parts

If another new type comes along we add it to the free or friction lists.

Tim

Was 8 hours enough?

I will start working on the new parts today as it more important to get them released than to get the old parts renamed.

Tim

14419.dat : "Plate 2 x 1 with Socket Joint-8 with Friction and Ball Joint-8"
63082.dat: "Plate 2 x 2 with Socket Joint-8 Square"


note that part 14419 spells out "with Friction" as this is very important.

Hi All,

To avoid duplication, please respond under here with parts you are working on.

Tim

I have modified or made:

63082.dat
98263.dat

14418.dat
14419.dat
14704.dat

joint-8-balla.dat [groove]
joint-8-ballb.dat [no groove]

joint-8-socket-freeb.dat [the old square socket used in 62082]
joint-8-socket-fricta.dat [the new socket]

Please feel free to make any minor corrections at review stage. I'm not sure how much time I'll have to spend on the parts.

OK,

Official parts 2508, 2736, 3184, 3614, 3731, 4089, 6571, 6572, 6574, 6628, 41895 are now back at the PT.

But they don't use the new ball-primitive yet, because I have some issues with them.

1.)
Why do the 8-ball-prim have an extra section of 4-4cyli?
I can't use joint-8-ballb.dat in part 3614.

2.)
I don't like the looks of the "joint-8-socket-fricta.dat"-primitive.
The pictures of the new sockets I can find show something else than the current design.
It should have rounded, softer corners and the hole is also rounded and spherical, not square or semi-cylindrical.
I doubt that the current design allow correct sideways movement.

3.)
I don't like the extemly long file names.
As an active author working in LDDP I do most of my editing in a text editor, and don't want to type it all out every time.
Please consider a shorter name for these new primitives.

4.)
I don't like to remove the word Towball from the descriptions. It has been present for many years now and is established.
If it is removed, let's add it as a keyword.


I'll gladly use them, but let's all agree and discuss it here, before I start integrating them.

I too, made a search in LDFind and found one other part that could use the new 8-ball-prim, 30219
30082 and 30395 need creation of another primitives, towball with a stringhole.

And howabout the old towball socket 3183 and 3730?
They are very similar to 3613 and 3491.
Could that socket-type be made into one primitive?

Magnus Forsberg Wrote:1.)
Why do the 8-ball-prim have an extra section of 4-4cyli?
I can't use joint-8-ballb.dat in part 3614.

Happy to change that one. The balla (was mis-written as balla before) will, I suspect, always be used with the cyli because the origin needs to be standardised.

Quote:2.)
I don't like the looks of the "joint-8-socket-fricta.dat"-primitive.
The pictures of the new sockets I can find show something else than the current design.
It should have rounded, softer corners and the hole is also rounded and spherical, not square or semi-cylindrical.
I doubt that the current design allow correct sideways movement.

They were made from the LDD pictures and could be wrong. Similarly I simplified some of the details to keep the file size smaller. My main goal is to get these very useful parts out in functional and useable form as quickly as possible

Functionally they work. I tested.

Quote:3.)
I don't like the extemly long file names.
As an active author working in LDDP I do most of my editing in a text editor, and don't want to type it all out every time.
Please consider a shorter name for these new primitives.

I too do everything by text. But I would prefer to use names that make sense rather than some complicated abbreviation that is unnecessarily short. I'm sure I'm not alone in typing faster than I can remember

Quote:4.)
I don't like to remove the word Towball from the descriptions. It has been present for many years now and is established.
If it is removed, let's add it as a keyword.

I believe it's long been LDraw standard that names should refer to form and function, but not use. Those parts are no longer "towballs". They are now ball and socket hinges. I agree we should keep the keyword, at least in the old parts.

Quote:I'll gladly use them, but let's all agree and discuss it here, before I start integrating them.

Yes. That is why this thread exists.

The only reason for making the 4cyl8sph-prim was to add a correct edgeline between the sphere and the cyli.
Maybe we could consider adding them into one file?

Are you saying that these new parts are in LDD? I can't find them.

Magnus Forsberg Wrote:The only reason for making the 4cyl8sph-prim was to add a correct edgeline between the sphere and the cyli.
Maybe we could consider adding them into one file?

Not exactly sure what you mean here. Maybe you should just modify the ballb part to something you can use. I really only added it as a placeholder and none of the parts I added use it so consider it totally free for editing

The important thing is that we use some sort of ball (and socket) primitives so that parts can be standardised and connections can be determined algorithmically.

Quote:Are you saying that these new parts are in LDD? I can't find them.

Sorry, I meant the early renders of the Mixels sets produced by LEGO's in-house CAD software.

Tim

Does this mean we should start calling the large Bionicle/Hero Factory-ball joints Ball Joint-12.81's?

There is a suggestion that the primitives be renamed to include Joint-8 first. I agree.

joint-8-socket-frica.dat - Joint-8 Socket with Friction
joint-8-socket-freeb.dat - Joint-8 Socket Square Free
joint-8-socket-balla.dat - Joint-8 Ball ????
joint-8-socket-ballb.dat - Joint-8 Ball with Straight Bar with Groove


Anyone see problems with this?

Tim

Yes, it is a good idea to define the connections, but do we need a primititve for that?
I've read some of the posts here in the forum about snapping parts in LDCad and SR3D.
Both use the primitives, but also need more information about how they are allowed to move or connect.

Think about how a common 2x2 brick is made. It has 4 studs on top and 1 understud on the bottom.
But there are 5 connection points both on the top and the bottom.

Maybe we need a ball primititve, but how about the sockets?
So far I have found 16 different designs .
[attachment=1158]
I don't think it is necessary to create primitives for sockets that are only used once or twice,
like the "joint-8-socket-freeb.dat - Joint-8 Socket Square Free"


Are all the axles connected to the balls of the same size?
This picture shows all the balls I've found so far. The green are fixed at the PT.
[attachment=1157]

There are some unofficial parts in the attached mpd

Hi Magnus,

Due to work commitments I am unlikely to have much (any!) time to deal with any of this for at least a couple of months.

But one point...

I chose to make "joint-8-socket-freeb.dat - Joint-8 Socket Square Free" as it is very likely to be used in future free moving socket parts. Most of the other parts, aside from the technic ones, are retired, and thus do not need so much need primitives.

Tim

The current design of the "joint-8-socket-frica.dat"-primitive is not correct.

If I measure it correct, I find that:
1.)
It should be possible to move the towball ~+/-35 degrees in the horizontal plane.
1 12 -24.574561 -4 -17.207293 0.819152 0 -0.573576 0 1 0 0.573576 0 0.819152 14418.dat
1 14 20 -4 0 0 0 1 0 1 0 -1 0 0 14417.dat
2.)
And if the axle on the towball is placed in a vertical position, it should be possible to move it ~+/-5 degrees.
1 12 -30 -4 0 1 0 0 0 1 0 0 0 1 14418.dat
1 14 -4 -19.923894 1.743115 0 1 0 -0.087156 0 -0.996195 -0.996195 0 0.087156 14417.dat
3.)
There should be a gap between the backside of this socket and a brick placed on top, or bottom, of it.
It isn't big, about 0.5 LDU, but easy to see.
1 12 -30 -4 0 1 0 0 0 1 0 0 0 1 14418.dat
1 14 -30 -12 0 1 0 0 0 1 0 0 0 1 3023.dat

I'm working on a rewrite, from scratch, if you don't mind, Tim.

Maybe someone could help me and verify my measurements?

Hi Magnus,

Thanks for checking all that. My primitives were made from rendered pictures so it's not surprising they aren't perfect.

I don't mind you doing a rewrite at all. Saves me having to do it

Tim

The socket-primitive is now reworked and all affected parts have been adapted to it.

I would like to renumber it too. "joint-8-socket-frica.dat" is too long.
IMO, the filename should not be used to "describe" the file content. It should be as short as possible.

I even think that we don't need these new ball/socket-primitives.
To me, it isn't a good idea to create all the differently shaped socket primitives, as seen above.
They are only used once or twice in a few parts each, and don't tell the software programmer how they are allowed to move.
They are sub-files, not primitives.

I don't see how the creation of these four new primitives solves the connection problem, if we also need to have the information about how they are allowed to move in a separate library.

Quote:I don't see how the creation of these four new primitives solves the connection problem, if we also need to have the information about how they are allowed to move in a separate library.

Using primitive/subparts permits adding the extra info to those files so any (future) parts will have (some level) of information without adding additional info.

At the very least it will offer a basic solution for those parts until the remaining details are imputed, something that could take quite some time depending on the time of the person doing that.

Just my 2cts from the pov of my LDCad.

Magnus Forsberg Wrote:I don't see how the creation of these four new primitives solves the connection problem, if we also need to have the information about how they are allowed to move in a separate library.

The ball should always have been a primitive IMO. The old sockets were used in limited parts so are more ambiguous. The new sockets are clearly the start of a new system and one expects that more are coming. Easier to start them as a primitive (like e.g. the click hinge) than separate them out later.

My 2c.

Tim

Hi

I was trying to follow the discussion above but I am slightly lost. I was trying to use the mixel ball/socket joints but they do not appear correctly in Bricksmith. Are these part actually complete and correct - I have a feeling it is me and I am doing something wrong...

As you can see, 14704 doesnt appear correctly, nor 14418 and in the leg portion, I can also not get 14419 to appear.

Can anyone advise me - I would be very grateful :-)

Elspeth

It looks like you're missing the socket primitive and maybe the subfile for 14419

Please download them from the Part Tracker here

Thank you. Can I just clarify, do only certain dat files go into the p or parts file within LDraw?

Apologies for the basic question but I am very grateful for your help and just trying to get the parts to show correctly.

Thanks

Worked it out when I realised the 's' within the dat file name would be subpart in the parts folder.

Thanks you so so much - I am sorted :-)

Elspeth

Yes, the unofficial files needs to be placed in respective, correct folders.

Dealing with Unoffical parts are described here.
And a great tutorial is found here.

(2015-09-06, 10:07)Elspeth De Montes Wrote: [ -> ]Worked it out when I realised the 's' within the dat file name would be subpart in the parts folder.

Thanks you so so much - I am sorted :-)

Elspeth

Hello, I also meet the same problem as yours and cannot fix it properly although I have followed the instruction as mentioned above....or did I do sth wrong when placing the dat files?  Below is my understanding for file path of some unofficial parts.

 14704

"14704.dat" placed in "parts" folder and the subfile "joint-8-socket-frica.dat" placed in "p" folder? 

 14418
"14418.dat" placed in  "parts" folder, meanwhile subfiles "14418s01.dat" placed in "s" folder and "joint-8-socket-frica.dat" placed in "p" folder?

Pls correct me if there is any misunderstanding... Thx!!