Exercise: Clay Linkage
The four-bar linkage is a fundamental mechanism used to transmit and
transform motion. Examples include crankshafts which convert between
reciprocating and rotating motion; reciprocating linkages to amplify or reduce a
reciprocating motion, e.g. the servo tie rods; concealed hinges; straight-line
mechanisms; and much more.
The purpose of this exercise is twofold: gaining experience working with
air-drying clay, and choosing a linkage design.
After this exercise, you should be able to:
Construct a mechanism from air-drying clay.
Choose four-bar linkage dimensions to create a specific movement.
Steps and observations
The overall objective is to create a four-linkage as a test: four rigid parts
coupled by four pivot joints with parallel axes.
Materials: air-drying clay and paper clips.
Please first duplicate and experiment with the “four-bar linkage demo” Fusion
360 design in the “examples - mechanical structures” folder of the “CKS
Course Resources” project of the “Dr. Zeglin” team space.
The Change Parameters dialog will identify the four link lengths as
parameters; please explore to find a set of link ratios which create a
Using the air-drying clay, fashion the four links to match the ratios. Be
sure to poke small pivot holes through. Relatively flat links are
acceptable, although considering the stacking dimension will make for a
better final fit. You may consider using wax paper or foil to separate parts
and form them in place for a more perfect fit.
Allow the links to dry overnight.
Use bent paper clips to form pivots and assemble the linkage.
Note: please your name as a prefix on the filename for all files uploaded to Canvas.
This will help me greatly keeping them sorted out during my review.
E.g., I might name my own files as “Garth-project.mp4” or “Zeglin-tactile.ino”.
The result of your explorations should include the following Canvas file submissions:
a brief video (~30 seconds) demonstrating operation of your device
one or more high-resolution photos