Specifying runner dimension constraints

In general, it is a common design principle that the minimum dimension of a runner section be 1.5 mm greater than the thickness of the part (mm). This allows the cavity to pack evenly and produce an even volumetric shrinkage.

Tip: It may be useful to run an auto runner balance without any runner constraints as a first pass, then use these new dimensions as the basis on which any constraints are set. This helps to avoid the risk of over-constraining a part, restricting the program's ability to provide a good balance for your runner system design.

1. Click (Select).
2. Click on the runner to select it. The runner section should be highlighted.
3. Right-click on the selected runner section and select Properties. A Runner dialog appears and all runners on the model with the same properties should now be selected.
4. In the Cross-section is drop-down list, select the required runner cross-section type.
5. In the Shape is drop-down list, select the required runner cross-section shape.
6. Click Edit dimensions... and enter the starting runner sizes and/or angles of the runners.
7. Click Edit runner balancing constraints. This allows you to enter the runner dimension constraints for the runner balance analysis to use when determining the optimum runner size.
8. In the Runner Balancing Constraints dialog, select Constrained.
9. Click Edit dimensional limits... and enter the minimum and maximum runner dimension constraints.
10. Click OK in all of the dialogs.