2. Sand Casting

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Sand Casting

aPriori Training

© 2009-2010 aPriori – Confidential, all rights reserved

Sand Casting Process Overview

Pour Solidification & Cooling Shakeout Cleaning

Purchased Metal

Sand Preparation

Make Core Boxes

Heat Treat Secondary Processes (Machining, …)

Off-line Inspection Heat Treat

Recycle Waste Metal

(Sprues, Gates, Risers, Runners,

Recycle Mold Sand

Tooling

Materials

Preparation Steps

Process Steps

Core Sand & Additives

CASTING PROCESSCASTING PROCESS

MELTINGMELTING

SECONDARYSECONDARY

Alloying

Binders, New Sand,Additives

ScrapMelting

Metal Charging

Make Patterns

In-line Inspect

TOOLINGTOOLING

Mold Making-Pack Sand- Set Cores-Add risers, gates, filters…

Finishing

Custom Mold Parts ( If needed)

Core Making

Optional Steps

SAND SAND PREPARATIONPREPARATION

CORE MAKINGCORE MAKING


Sand Casting Mold Elements

Chaplets


How aPriori Works – Sand Casting

aPriori Geometry Assessment

Process Routing Engine

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aPriori VPE’s Supplier VPE’sCustomer VPE’s

Geometric Cost Drivers

Physics Based Mechanistic Models

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Physical Manufacturing Capabilities

Cost Accounting Data

Process Capability & Routing Rules

Cost Models

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Configured Data Layer

aPriori User Interface

Patent Protected aPriori IPP

Non-Geometric Cost Drivers

© 2009-2010 aPriori – Confidential, all rights reserved© 2009-2010 aPriori – Confidential, all rights reserved

Sand Casting GCDs: Draw Direction

Draw Direction

Click to Override

Possible parting planes (blue)

Current parting line (orange)

Advanced parting line option


Sand Casting GCDs: Holes, Voids, Thickness

Min & Max ThicknessMold and part feasibility

VoidsCandidates for core

HolesEvaluated for core or other operation based on size, shape orientation and tol.


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Sand Casting GCDs: Combo Voids

Combo Voids = Voids merged with Holes

Combo Voids are considered as a single feature in the casting process

You can Merge and Unmerge Holes from a Combo Void

This may result in a different routing, part cost, and tooling cost


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Sand Casting Process Routings

* Only one of these four is part of the process

Melting Core Making

Oil Core

C02 Cured

Hot Box

Isocure Gas

No bake

Shell

Mold Making, Pouring,Cooling

Shakeout Cleaning Finishing In-line Inspection

Stock/Extruded

Mold Making Pouring Cooling

Manual Standard

Dashed = Optional Process

•None or all of these can be part of the process


Manual Floor


Horizontal Automatic


Vertical Automatic


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Selecting Molding Type and Machine

Patent Protected aPriori IPP


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Process Capability and Routing Rules

XMolding Type

Selection-Compares part size to

machine flask size for each machine in the mold type

-Selects first feasible machine

-Calculates the number of cavities that will fit in the mold

32” x 6” x 6”

XXXXXX

Selected VPE

Configurable Data Layer


MoldingSelects first feasible based on part and machine size

Sand Casting Machine SelectionMeltingLowest conversion cost

CleaningSelects first feasible based on machine capacity (# of parts) and size

Cooling, Shakeout, InspectionVPE default machine

PourSelects first feasible based on part weight and ladle capacity

FinishingSelects first feasible based on part weight and machine capacity

Core MakingSelects first feasible process that can fabricate all cores based on core box size


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How aPriori Works – Sand Casting Cycle Time

Time Calculations-Calculated for each

feasible routing-Machine Cycle Time-Machine Setup Time-Labor Handling Time

Material Calculations-Yields-Material Utilization

Physics Based Mechanistic Models


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Physical Manufacturing Capabilities

PSelected VPE



How aPriori Works – User Overrides with Process Setup Options

Recommendation: leave draft, rounds, min thickness unchecked until design matures

Check for DraftsCompares drafts on part to variables in VPE

Check for RoundsCompares sharp corners on part to variables in VPE

Check Minimum ThicknessCompares minimum wall thickness of part to minimum allowable wall thickness from material table

Number of Cavities•Calculated value based on mold size •Direct user override


How aPriori Works – Sand Casting Cost Model

Variable Costs• Material• Labor and Overhead• Setup

Capital Investments• Pattern Making• Core Box

Amortized Investments• Investment per Part

Expendable Tooling• Sand for cores and

molds

Cost Accounting DataPhysics Based

Mechanistic ModelsP

Cost Models

PSelected VPE



Tips for Use – Sand Casting

Check the Parting lineThere can be multiple “good” parting line assignments depending on part geometryParting line assignment affects the number of cavities (as seen in the Process setup screen)

Look for Combo Voids and unmerge features if appropriateApply Machining with One-Click-Costing

Apply tolerances/roughness to individual featuresAs the part design matures, verify the cavity count and machining requirements

User can override cavity count via Sand Casting Process SetupFor as-cast designs: do Draft, Rounds, and Minimum Thickness feasibility checks toward the final stages of design

As manufacturing details are known about the part, verify mold making routing, machine selection and coring process

User can override coring process down to the individual GCD if they have requisite knowledge or info


Tips for Use – NX Machined Castings

2010 R1.1. Improvement for NX files with a single subcomponent and Machining cuts

Behavior in aPriori 2010 with the NX beta configuration propertyaPriori always recognized these files as assemblies (not parts)

Behavior in aPriori 2010 R1.1Users can control aPriori’s behavior based on an additional property:apriori.free.bodies.preserve.CAD=false

Set to false, aPriori opens those files as machined parts

Set to true, aPriori opens those files as Assemblies with 2 subcomponent parts (cast part and machined part)

Limitation: If a model contains a machined part, its cast version AND other subcomponents, aPriori will still interpret it as an assembly.

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2. Sand Casting