Jointing Ball Joints? HOW?!? D:

Yeah, it's incredibly hard, those ball joints! From finding the right size, to getting them to fit and move correctly. It's an enormous challenge. I use wooden balls from Michael's arts and crafts store. For the legs, I prefer the oval shape joint, but that makes things even tougher. A regular ball is probably better for your sanity for the first doll. It's a good idea to have the exact right size balls before you even start creating your doll, and sculpt it using them from the start. It's best to have a detailed drawing of your doll in the exact size you want, with the ball size you want at each joint. Other people here probably have better information than this. It'd also be good to go to a few local meet-ups in your town and have a look at other people's dolls. If there aren't any meet-ups in your area, I'd really recommend saving up to buy a doll. A good excuse to justify the purchase would be that you need it for an artistic reference!

 

This thread is pretty helpful, I really don't know why it isn't in the sticky: http://www.denofangels.com/forums/showthread.php?t=121301

 

You might want to consider buying Yoshida's book on creating ball jointed dolls, he explains the balljoints into great detail.

 

The amazing Twigling has a great tutorial on her website of the physics of ball-jointing and many variants on ball-jointing dolls. It's (iirc) 30 pages of .pdf document.
I don't have the link handy; I'm sorry. But looking her up ought to get you closer.

Ann in CT

 

The PDF that Ann in CT is talking about can be downloaded from here.

I've now added sand3's jointing thread to the stickies, as well.

And I heartily recommend Ryo Yoshida's "Yoshida Style Ball Jointed Doll Making Guide"!! There's a thread about an in-progress translation project here. The book itself can be found on eBay & HLJ.com.

 

I use this page, she does other great tutorials as well, but I also watch restringing videos to see how all the joints are shaped and strung.