Fig. 3 – Assemble Tree
STEP 3:
The wax patterns are attached to a central wax bar, called a sprue, to form a cluster or tree. This tree provides the pre-engineered feed metal gating requirements are able to be met, while at the same time providing the support needed to hold the wax patterns in place throughout the shelling process. Niagara Investment Castings has several pre-engineered sprues, including multi leg, and bottom pour sprues for enhanced casting quality of difficult to pour alloys. The sprue has a ceramic pouring cup already attached to the top to provide a solid, clean metal pouring port for the casting operation to come, as well as a metal support rod embedded in the wax sprue to allow our robots to grip onto the wax tree to perform the shelling operations.