Atlas
Classic Grashof driver. The coupler traces a one-loop sextic.
Dynamics
Reduced Euler–Lagrange on the crank. Loop closure gives every bar pose; the Jacobian builds M(θ). Two torsion springs. Viscous damping at every revolute. No gravity.
Neutral 63.0°
Neutral 68.8°
Projective readout
- Class
- Crank–rocker
- Grashof s+l
- 5.50 ≤ 7.00
- θ₃ coupler
- 24.3°
- θ₄ rocker
- 83.7°
- Transmission
- 59.5°
- A
- [0.68 : 1.34 : 1.00]
- B
- [4.33 : 2.98 : 1.00]
- P
- [2.03 : 4.19 : 1.00]
- O₆ cognate
- [2.40 : 2.05 : 1.00]
- Roberts–Chebyshev
- 10-bar · 3 four-bars · 1 sextic
- Radical axis C₁ − C₂
- 6.64x − 2.67y − 20.75 = 0
Joint A rides a circle about O₂; B rides a circle about O₄. Their common points are the pencil C₁ − λ C₂, reduced to the radical axis cut with C₁. P is the image of that pair under the rigid map of the coupler, so the locus is a sextic.