MOTION
FOUNDRY
AN EXPERIMENT IN
COMPUTATIONAL CRAFT
All experiments ↗VOL. 002

FROM A GESTURE TO A GEOMETRY

DRAW A PATH.
FIND A MACHINE.

A line on a page becomes links, joints, and motion.
Sketch a loop. Find the mechanism hiding inside it.

ONE MOTORREAL GEOMETRYENDLESS LOOPS
DESIGN STUDY 001READY TO EXPLORE
KINEMATIC ASSEMBLY

A machine in the making

TOP VIEW
ONE COMPLETE CYCLE
YOUR PATHMACHINE PATHRIGID LINKS
DRIVE SPEED0.45 rev/s
TAKE IT APART

Make the mechanism yours.

Move the tracing point. Watch the path change.

POINT POSITION / U
POINT OFFSET / V
ASSEMBLY RECORDYOUR NEXT SMALL INVENTION
Search for a mechanism to see its dimensions.

NOTES FROM THE WORKSHOP

YOUR LINE.
A MACHINE'S LOGIC.

Draw the motion you want. The foundry searches through two families of mechanical linkages, changing their proportions until the tracing point comes close to your line.

  1. Close the loop.A motor turns a crank at a steady speed. Connected rigid bars constrain the tracing point to one repeating path.
  2. Try, measure, refine.A collection of valid mechanisms seeds a population search. Better fits survive, and local refinement adjusts their geometry.
  3. Look at the difference.Path deviation is the average ordered distance between uniformly spaced points on the two curves, as an RMS percentage of your drawing's diagonal. Lower is better. It does not promise an exact match.
The engineering & research

Four-bar and offset crank-slider mechanisms use exact analytic joint closure and one fixed assembly branch. Full-rotation constraints prevent impossible candidates. Similarity alignment removes translation, rotation, and scale from the geometry search.

The approach takes inspiration from retrieval plus refinement in LInK (2024). Recent work such as LinkD (2026) explores learned generation of broader mechanism topologies. This workbench runs its own numerical search in your browser.

These are kinematic designs, not certified construction plans. Link thickness, collisions, loads, joint clearances, and motor torque are not simulated. Exported dimensions use arbitrary design units.

A little more than a drawing.
A little less than a factory.