Where can I find tiny U-joints for precision joint connections?

[DaveC426913]

I am looking for joint(s) small enough that I can attach four of them at one point and still have them smaller than 1cm. U-joints would be small enough but may have too much "play". Ball joints probably don't come four at a time.

I've looked at a dozen ways I could build such joints from scratch (using simple elastic or springs), but they all suffer from fatigue or excessive play.

Even LEGO joints are too large, although they're within a factor of two.

Can anyone direct me to a source (presumably online) that has tiny parts like this, or where I can ask about tiny parts?

 

[berkeman]

Can you post a sketch of what you want the joint(s) to do?

 

[bsheikho]

Possible 3D printing job?

 

[Mech_Engineer]

When you say joints, do they have to be rigid (as in joining a frame's trusses), or flexible like a u-joint?

 

[DaveC426913]

When you say joints, do they have to be rigid (as in joining a frame's trusses), or flexible like a u-joint?

I want to being 4 rods together at a point, where each rod has about 90 angular degrees of freedom (i.e. 45 degrees in any direction from straight).

The vertices of this tesseract is what I'm trying to build.

To rotate this tesseract inside out, each vertex needs to be able to transform into any other.

 

[Mech_Engineer]

What will you be using for the spar material? If you're using something magnetic, you could consider trying to use magnetic spheres like these: http://www.kjmagnetics.com/products.asp?cat=12

 

[Nidum]

http://www.minibearings.com/about/

 

[DaveC426913]

http://www.minibearings.com/about/

Great find! Thanks!

A pity their smallest U-joint is an inch long.

But it gives me some ideas for searching.