Mannequin with Print in Place Joints

This is a study on print-in-place articulation.

I wanted a small anatomical figure that was jointed. I found other great designs where you print the respective parts then assemble, but scaling down caused difficulties as the smaller snap in parts would easily disconnect.

By printing in place the joints, I was able to get it under 100 mm.

Also, in the elbows, knees, ankles, waist and neck, I printed 1 mm pins with corresponding recesses that limit the rotation. (See the section analysis in the attached photos.) I did not have any luck with the hips as the movement needed caused it to be to unstable. I also left the shoulders and wrists to fully rotate but may circle back to that at some point. (Suggestions are welcome.)

The tolerances are very tight to try to keep some friction in the joints. The target was moving but posable and got it on most of them.

I am including the step file to make it easier in case you want to take a shot at other modifications.

If you scale up, the joints will be very loose so you will have to run test prints to get to the target motion and friction.

If you like, you can also deboss lettering on the front and back. At this size, though, there is little room for text. Displayed is a 5 mm tall, 1 mm deep “C 6”.

Printing notes:

1. PLA
2. 0.10 mm layer
3. 4 perimeters
4. 15% infill
5. Support from build plate

The joints do stick sometimes and because it is so small, and the tolerances so tight, they break, so have patience, increase the joint tolerances or scale up. 😉

Update 2024-10-01:

I was able to get the mannequin to stand up by tightening  the hip joints down to 0.12mm.

I have replaced the gcode, stl and step files with the new versions.