A) The blank for the spool shown in the figure attached is to be sand cast out of aluminum casting alloy (A-319). Make a drawing of the wooden pattern for the part, include all necessary allowances for shrinkage and machining.
B) Concerns in casting include "hot tearing", due to uneven cooling of the part. "Chills" are used to absorb heat in areas where the hot tear is likely to occur. They promote even cooling. Indicate where chills may be used in the present design.
C) The part is to be redesigned for casting purposes. The existing design is prone to "hot tears" and "piping". A design which has a constant thickness is the best alternative, with smooth transitions in geometry. Make a drawing of a redesigned spool which will accommodate these objectives.
D) The spool will be lighter as a result of the redesign in part c) above. Estimate the decrease in weight.