The Runner System should be designed in such a way that all of the parts finish filling at the same time. This can be achieved by balancing the runner system.

Before the design of runners for a family mold, analyze each part on its own. Once we know that each cavity is Filling properly, the runner system can then be designed & created for a balanced Fill path in each cavity. If the runners are not balanced, molding problems such as hesitation, underflow and over packing may occur.