So in-place printing is the “holy grail” for 3D printed designs with moving parts. But is in-place the best option in all situations, specifically for small moving joints that could be used in a small (150mm) articulated figure?

Aiming for a model of that size I estimated that the joints would need to be a cross-section of 10mm x 10mm. The shafts (pins) what would allow rotation would be 5mm in diameter. A simple joint design would be as shown to the right, allowing for the joint to flex a full 180 degrees (and so be good for arms and legs).

This model splits down into three pieces which I'll call the link (shown in blue) and parts A and B (shown in red and green). It's worth noting that part B is just a mirror of part A.

To print this joint as separate pieces just needs the model separating.

I found that the joint worked best when the holes were slightly bigger than the shafts. The diameter of the hole was 5.05mm and the shaft was 5.00mm; this allowed the pieces to be fitted together easily but maintained a level of stiffness that an articulated figure would need.

I also added a slight bevel to the ends of the shafts to make them easier to fit.

No other adjustments were needed to the model.