****** Piston ****** .. admonition:: Reference :class: refbox :Panel: :menuselection:`Physics --> Rigid Body Constraint` :Type: Piston A piston permits translation along the X axis of the constraint object. It also allows rotation around the X axis of the constraint object. It is like a combination of the freedoms of a slider with the freedoms of a hinge (neither of which is very free alone). Options ======= Limits X Axis Enables/disables limit translation around X axis. Lower Lower limit of X axis translation. Upper Upper limit of X axis translation. X Angle Enables/disables limit rotation around X axis. Lower Lower limit of X axis rotation. Upper Upper limit of X axis rotation.