Update

- Slim variant added to models

Model and Scaling

I made this ball joint for one of my designs and decided to make a bare version of it that you can extend and adapt to your liking. You can also just take a look at the design and take measurements, if you want to do something similar.

The design of the joint itself is of greater mechanical strength than other designs with a slotted joint socket. This design adds a bit of material and might give up on some slenderness, but should overall be more durable and withstand more duty cycles.

The ball comes with an M10 threaded pin, a bare pin and without any sort of pin. This way you can choose what workes best for your design. Either print the connecting part with a thread, a hole to glue the ball with pin into, or model your own connector with the .step-files I also uploaded.

The socket has no additional extension or thread but has a pretty wide base which should be ideal to glue stuff to it or model something, that you want a ball-joint-socket attached to.
When scaling the model keep in mind, that the threads might be difficult to print if they are not sufficiently large and also might require different tolerances. The version/size I uploaded workes perfectly for me with enough play for easy turning but without woobling.

Printing

I printed all parts oriented with their thread-axis normal to the printing surface (standing basically). This ensures that the threads have the greatest chance of being printed properly.

Especially for small threads I would advice to use 0.1mm layers or less. I used 0.08mm layer height on an Ender 3 style printer with a 0.4mm nozzle. This also makes the ball and socket nice and round.

As these are mechanical connecting parts you should use 3 or better 4 perimeters and at least 30% infill. This ensures enough mechanical strength for the threads. But despite this keep in mind that threads can create huge axial forces pretty fast when thightening, so don't overdo it. The parts should lock tight together without the need for extrem tightening.

There is no need for supports for all parts as they are.