Casting Cost Model Enhancements
aPriori 2019 R2 SP1 contains several enhancements to the Degating process in the Casting-Sand process group:
• Specialized degating machines have been added to the Degating process. These types of machines break off the gating systems using blunt force and are appropriate for cast parts made of brittle ferrous materials such as Ductile Iron, Gray Iron, and Malleable Cast Iron. Several different types of these breaking type degating machines were added:
o Power Hammers – these are pneumatically-operated single-blow impact hammers designed and intended specifically for iron foundries to knock off risers, feeders, gates, runners. 7 different Power Hammer machines were added to the 2020-01 aPriori Regional Data Libraries.
o Hydraulic Foundry Wedges – these machines use a hydraulic cylinder to drive a wedge in-between the casting and the riser. 5 different Foundry Wedge machines were added to the 2020-01 aPriori Regional Data Libraries.
o Degating Centers – these centers utilize Foundry Wedges to remove gating system from casting parts, but also utilize conveyers to increase throughput by enabling parts to be degated while moving down the conveyer. Five different Degating Center machines were added to the 2020-01 aPriori Regional Data Libraries.
o Degating Centers and Foundry Wedges typically are used for smaller parts while Power Hammer machines handle larger parts.
• Metal Cutter machines also were added to the Degating process. These hydraulic-powered machines use a scissor-like action to cut risers and feeders from parts made of non-ferrous materials such as Aluminum, Copper, and Bronze alloys. 2 different Metal Cutter machines were added to the 2020-01 aPriori Regional Data Libraries.
• The Degating machines available in previous releases (Band Saw, Circular Saw, and OxyFuel torch) still are available. These were updated to now include part load and unload times in the Degating cycle time calculation; previously these times were neglected. For the Band Saw and Circular Saw, the machine selection rules also now consider whether the machines are capable of cutting a large-enough diameter to accommodate the part; a new machine field Max Cut Diameter was added to the machine table for this purpose. The max weight limit for the Band Saw machine also was increased as it is capable of handling parts up to 227 kg.
The type of machine selected by aPriori is determined based on criteria including the part material, the size (mass) of the part, calculated ingate and riser diameters.
Due to these enhancements, a different Degating machine may be chosen when costing a sand-cast part in aPriori 2019 R2 SP1 compared to the previous release, resulting in a small change in cycle time and cost estimates for the Degating process. Even if the same machine is chosen as previously, a small increase in cycle time and cost will be observed since load and unload times now are included.