Inspired by and reversed engineered from Isaiah's Friendly Articulated Slug, these are base articulated joints that can be used to to build articulated models off of. I have included the original solid model files as well as generic drawing files so that it's easy to identify what are key features and tolerances for the print-in-place flexi capabilities.

These Joints are capable of snapping together post-printing as well as able to be printed in place in assembly/flexi form.

I've only posted STLs of the joint at an 8 mm diameter size but you can use the solid model to adjust the size and tolerances to your needs.

Successfully printed without a need for supports in 0.28 mm and 0.12 mm layer heights.

Files - Explainer

.STL

• WeeksB_Joint-SINGLE.STL - This is a single, un-assembled joint in STL format. It can be snapped onto any other Joint files to extend your assembly by one.

• WeeksB_EndCap-Neg - This is a single, un-assembled joint that will only attach to the positive/prong end of an assembly.  Use it to create a smooth end. - Shown in last image

• WeeksB_EndCap-Pos -  This is a single, un-assembled joint that will only attach to the negative/recessive end of an assembly.  Use it to create a smooth end. - Shown in last image

• WeeksB_JointxFIVE.STL - Is a five joint print-in-place assembly in STL format. It can be snapped onto any other Joint files to extend your assembly by five.

• WeeksB_JointxSEVEN.STL - Is a seven joint print-in-place assembly in STL format. It can be snapped onto any other Joint files to extend your assembly by seven. - Shown in second image

• WeeksB_JointxTEN.STL - Is a ten joint print-in-place assembly in STL format. It can be snapped onto any other Joint files to extend your assembly by ten.

.SLDPRT

WeeksB_Joint.SLDPRT - is the solid model with equations and print-in-place flexi tolerances included. You can modify this file to create the ideal joint and number needed for your project.

.PDF

• JointDrawing-Assembly.PDF - A quick drawing of the assembly of two joints to show the required gap tolerances for FFF printing that requires minimal to no post-processing to obtain movement. It also shows the overall geometry that makes the joint magic.

• JointDrawing-BeforeRounding.PDF - A quick drawing of the required geometrical dimensions that make the joint magic BEFORE the part is deformed to get the rounded shape that provides Z motion. If the joint is created without rounding, only X and Y motion will be possible.