Customizable Saddle Joint Model - Working Synovial Joint Teaching Model

WORKING SYNOVIAL JOINT MODEL - SADDLE (like the base of the thumb) Customizable parametric teaching model - sizes and clearances are sliders in TrueGeometry Playground (free, in the browser).

Two curved saddles sit at 90 degrees to each other, so the top one rocks forward-back AND side-to-side but does not twist - the joint at the base of your thumb.

This is one of six models in the Synovial Joint Teaching Set (hinge, ball-and-socket, pivot, saddle, plane, ellipsoid) - collect the full set for the classroom.

SIMPLIFIED TEACHING MODEL - not anatomically exact. For education and demonstration only. Not a medical device, and no medical claims are made.

WHAT YOU GET - Full assembly STL (all parts in place, print-in-place where noted) - The complete TrueGeometry Playground recipe (customize sizes, $GAP clearance) - How-to-run-scripts guide (PDF)

PRINT NOTES - No supports needed; parts print in place with $GAP clearance (default 0.5 mm). Tune $GAP for your printer. - Overlapping shells are intentional - the slicer merges them. No booleans except the cup cavities (noted in the recipe). - PLA works well.

HONEST STATUS Designed in TrueGeometry Playground, not yet test-printed by us - please post a Make if you print it. AI-assisted design.

The full recipe (every command, ready to paste) is attached in Other files, and the included guide PDF shows how to run and customize it step by step. Customize it in TrueGeometry Playground: https://www.truegeometry.com/CoreWebGLTG/KBEAgentHTTP.html

License: CC BY-NC 4.0 - free for students and teachers to print and share. Commercial use requires TrueGeometry's consent. Read the full build + customization guide: https://blog.truegeometry.com/0_0_0_0/blogs/post-68a70c6d.html