A robotic case packing system loads articles from one conveyor into containers on another conveyor using a robotic pick and place mechanism and a set of pivoting bins. A controller moves the robotic mechanism in first picking movements to pick and place articles from the conveyor into the first bin. Once the first bin is full, the controller pivots the first bin to allow the articles stacked in the first bin to be loaded into a container held below. While the first bin is pivoting, the controller moves the robotic mechanism to pick and place articles from the conveyor into the second bin. The process repeats with the controller pivoting the second bin during the picking movements used to fill the first bin and vice versa.