Machinery TwinSlider-crank
The classic 3-link mechanism, driven from either the crank or the slider.
The slider-crank converts between a rotating crank and a reciprocating slide: piston motion, pushers, cutters, shakers. One variable drives all three links, and the Driver setting determines whether that input is crank angle or slider position.
Parameters
| Parameter | Meaning |
|---|---|
| Driver | Crank-driven slider or slider-driven crank |
| Input variable | Crank angle in degrees, or absolute slider position along local X in metres |
| Crank length | Length of the crank arm |
| Rod length | Length of the connecting rod |
| Y offset length | Offset of the slider rail from the crank center |
| Crank solution | Which of the two mathematical assemblies to use |
Links & models
The mechanism renders three links, crank, rod, slider, each with its own model slot and model-space offset. Import each part's CAD and align it per link; see Coordinates & units for the model-pose alignment workflow.
The solution flag
For a given input the mechanism can have two mathematical assemblies. If it assembles inverted compared to your machine, flip crank solution. In slider-driven mode the same slider position maps to two crank angles, so the flag chooses one half-cycle branch; slider position alone cannot determine continuous rotation through a dead centre.
Driving it
- Continuous cycling, a MasterTime over 0–360°.
- PLC-driven, map the crank angle to the drive axis position in Online mode; if the axis reports revolutions or counts, use the variable's scale factor to convert to degrees.
- Slider-driven, map the absolute local-X slider coordinate in metres. Inputs outside the linkage's reachable circle-intersection range keep the last valid pose.