Gates connect the runners to the mold and move the melted plastic from the runner into the mold cavity.
The plastic is injected under high pressure into the cavity so that the cavity fills up completely and creates a tight, clean product. The size, sharpness, number, and location of the gates all impact on the quality of the finished plastic part.
Since the runners taper into the gates, design the gate system at the same time as the runner system. Before you can create a gate, identify a gate location. After creating the runners, connect the runners to the gate locations.