This simulator puts three one-degree-of-freedom joints next to each other: a revolute hinge that rotates, a prismatic slide that translates, and a helical lead screw that couples rotation to travel. Move each and compare how the joint type limits the allowed relative motion.
• A revolute hinge with arm, a prismatic guide with carriage, and a helical lead screw with nut, together with guide supports, a scale and labeled joint axes. • Sliders for revolute angle (-120° to 120°), prismatic travel (0-0.4 m), helical turns (-2 to 2 rev) and screw lead (5-30 mm/rev), plus a check box to cycle all three mechanisms. • Readouts for revolute displacement, prismatic displacement, helical rotation, helical translation in millimeters, and the degrees of freedom of each isolated joint. • Experiments for pure translation (0.3 m with no orientation change) and lead-screw coupling (two revolutions gives 20 mm at the default lead).
A revolute joint rotates a point about an axis, p = R(axis, q) p0. A prismatic joint translates it along an axis, p = p0 + axis × travel. A helical joint couples the two: travel equals lead × revolutions, so specifying rotation determines translation. Although you see both rotation and translation in a screw, it still has one independent coordinate, which is why degrees of freedom count independent coordinates rather than visible motions.
All joints are ideal and rigid, with no backlash, compliance or friction. Helical translation is visually exaggerated for readability, so use the millimeter readout for the real value. Automatic playback is a prescribed comparison, not a dynamics solver.
A revolute joint allows rotation about a single axis, while a prismatic joint allows translation along a single axis. Both have one degree of freedom but produce different kinds of tool motion, as the side-by-side mechanisms show.
The screw lead links rotation and translation: travel = lead × revolutions. Once one is chosen the other is fixed, so there is a single independent coordinate even though the nut both turns and advances.
Lead is the travel per revolution. A larger lead moves the nut farther for the same number of turns, for example 20 mm after two turns at 10 mm/rev, at the cost of less mechanical advantage.
No. The joints are ideal, rigid pairs used to compare kinematic behavior. Real joints have friction, compliance and clearance that this lab deliberately leaves out.