Lego Technic Ultimate Wheel Hub

[nicjasno]

You want it to resist being thrown out of the socket on both sides equally.

[aol000xw]

There are "3 sides" so perhaps sideways...

[Front]

Maybe the ball with a cross hole through it (part exist), can actually squeeze in between the half-beams, and then be rotated so the ball surfaces align.

[nicjasno]

Just drew up some quick sollution.

This is the hub viewed sideways/top..

The ball joint in the "now" version has to spread the 2 half stud liftarms quite a bit to get into its socket.

In the "?" version this would be much lower with a more pronounced "entry" into the socket

[Hrafn]

Maybe the ball with a cross hole through it (part exist), can actually squeeze in between the half-beams, and then be rotated so the ball surfaces align.

The issue with that is you'd have to then put an axle through the ball to act as a suspension link, and loads along the length of that link would tend to pull it apart over time.

[VKTechnic]

Victor Kojenov:

Those tires will not do. They have no edge that would sit in a rim. They need to be glued to a special r/c rim.

Rims would look something like this:

Not sure if gluing is really necessary

[Front]

The issue with that is you'd have to then put an axle through the ball to act as a suspension link, and loads along the length of that link would tend to pull it apart over time.

I sometimes joke that we need axles with stop at both ends

[nicjasno]

VK: i know. I have such rims and tires. My issue with this is that the tires need to be glued to the rims, otherwise they will not hold. And this sucks :(

Edited February 8, 2014 by nicjasno

[VKTechnic]

Is gluing really an issue though? If the rims will be 3rd party (through 3d printing), then gluing shouldn't be a worry for most people using the rims. And if we're looking at LEGO making the tires, they've made glued tires in the past.

Also, these rims will probably be used with just one set of tires (like the tires I posted earlier).

Edited February 8, 2014 by Victor Kojenov (TFOL)

[nicjasno]

That is true, but the glued on tires always tend to wobble.

[Boxerlego]

The ball socket in the latest version is moved 1/2 stud closer to the center on each side if you haven't noticed. This makes the socket much sturdier, and if necessary it can be further strenghtened, so no worries.

This is the latest version, just so you know what i'm talking about:

Yes I've notice both versions. I cant replicate that ball socket distance of 5 studs on a wheel hub designed nor can I replicate that ball socket distance of 6 studs either, The ball socket distance that is achieved with this wheel hub setup here is 7 studs and is just too big to fit inside the unimog's wheel rim, a wheel hub with a 5 studs ball socket distance on a wheel hub would fits well inside the unimog's wheel rim. Why don't you use the Unimog wheel rim size as your base for your wheel hub design?

With its cross design with dual holes is pretty easy to reinforce the arm if necessary, so no, I do not think that over time it will break. Is just a matter of understanding the part design, the forces involved and using it properly.

I understand you can reinforce the arm for some hub designs but that completely disregards the process of building with the ball joints overall. The ball is 10 mm big in diameter and the distance across a brick is 8mm. That means 2mm of travel must be distributed evenly across the ball socket connection and that requires some force. I do understand the parts design and the forces involved and using it properly. The mechanical behaviors behind the ball socket plus a axle hole stack on top appeared just to demanding on each other optimal structural form. I was speculative on the Idea of having a ball socket with a axle hole. I had no experimental proof whether the connection was going to work or break and because of this I focused my thoughts on the mechanical behaviors about both the ball socket and axle hole and I deduced it was going to break simple as that.

To incorporate every suspension setup in one simple design would need to incorporate a building guide to show all what you can do and how to build it the right way and that is why I think another approach on the ball joints is needed here, not only to ensure a consistent quality of performance from design to design, it will also further improve upon the form and function here.

The material in the ball socket behind the ball has no real impact on the friction a ball will have in there. And surely it should be made with a play, though as low friction as possible.

But the hub design will never work. To get a ball into the socket, the material of the two half-beams has to bend way too much. A material that can handle such short lasting but very high deformation, can't at the same time include cross holes, that has way different demands to the material used.

But it's interesting to see you guys having ideas about designs. I'm the Technical Designer for the 2015 Technic parts. My first year in the Technic team. I hope to have more influence of what parts will appear in 2016. RIght now I'm just working on the stuff the set designers has developed.

Erland

Part Design

Thanks for confirming my thoughts on the ball socket with axle hole connection. I've already expressed some of my thoughts here on wheel hubs But I would like to see if the CV ball joints could really handle the power of a XL motor or even better, I know the U joint can.

[nicjasno]

Yes I've notice both versions. I cant replicate that ball socket distance of 5 studs on a wheel hub designed nor can I replicate that ball socket distance of 6 studs either, The ball socket distance that is achieved with this wheel hub setup here is 7 studs and is just too big to fit inside the unimog's wheel rim, a wheel hub with a 5 studs ball socket distance on a wheel hub would fits well inside the unimog's wheel rim. Why don't you use the Unimog wheel rim size as your base for your wheel hub design?

Because the unimog rims are much too small. The wheel hub fits in the silverchampion rims.

[Alasdair Ryan]

What about a two part holder design based on the sketch above where you would put two of those on top of each other,enclosing the ball joint tightly.

Of course you would need to have some way of tiring the two halfs together with a beam of some sort.

[nicjasno]

You're complicating :)

[nicjasno]

So we finished up the multilink suspension, so you can see what i'm aiming for:

[VKTechnic]

Looking good, keep it up! I wish there was a way to 3D print tires...