Mechanism Builder — Draw It, Count Its DOF, Watch It Move
Build any planar linkage from links and joints · constraint-based kinematics
MODULE 0
Build Tools
Mobility (Degrees of Freedom)
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Degrees of freedom
Angle between links
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Transmission angle μ
μ is the angle at the joint the two links share. 90° transmits best;
Norton's usable band is 40°–140°. Pick a different pair with
Measure ∠.
Links
Joints
⟳ drive makes a joint a motor — one per degree of freedom.
remove motor stops it driving. ✕ deletes the joint.
Inversion
Hold a different link still. The chain and its relative motion are
unchanged — only your reference link. A slider-crank inverted gives the
quick-return and the Whitworth.
Examples
Mechanism CanvasScroll to zoom · Right-drag to pan · Double-click to reset
θ = 0°
Move it by hand: drag the slider, type a θ, press ← →, or grab a link with
the Move tool.