Runner Guidelines

The objective of good runner design is to provide an efficient path that will fill the cavity as quickly as possible, with proper material temperature and  minimal scrap.

Cold Slug wells must be incorporated into the runner at every branch.  The cold slug well should be from  .5 - 1 Dia of the runner in length.

A balanced runner system is highly desirable.

On large runner systems, more than one sprue puller may be required, as well as ejector pins.

The smallest runner permissible is desirable with reference to cycle time.

Runner sizes and angles (trapezoidal) should be equal to standard cutter sizes.