A crop machine having a first frame section pivotally connected to a second frame section, wherein each frame section is supported by hydraulic float cylinders directly controlled by an electronic control supplying a variable control signal to a PPRR valve arrangement to maintain a float pressure in each hydraulic cylinder at a predetennined value. The electronic control is arranged, in response to variation in a position sensor signal that provides an indication of movement and/or acceleration and/or velocity, to adjust the control signal to vary the lifting force of each hydraulic cylinder. A common accumulator is included, such that downward flexing of the second frame section forces additional fluid into a first hydraulic cylinder to apply additional lift pressure to the first frame section and upward flexing of the second frame section removes fluid from the first hydraulic cylinder to apply reduced lift pressure to the first frame section.
