Library › Mechanisms › Tusi couple: straight line from a gear rolling inside a ring twice…

Assembled mechanism, all parts placed at one pose (STEP keeps each part separate)

Exact dimensions. True size, no printing tolerance added. Threads are plain cylinders at the major diameter.

STEP STL free, CC BY 4.0 (credit "Xem Studio")

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From the full sheet

Tusi couple: straight line from a gear rolling inside a ring twice its size: every size, notes, mating features and sources. How does a Tusi couple make exact straight-line motion?