are difficult to machine as inseparable part of the mould or die cavity will most likely wear or break during the moulding or casting process

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Core extraction Tampere University of Technology Tuula Höök Theoretical background CAD tools in the exercise Cores 3 Mould structure Manufacturability Steps to follow Take the model

Select the core side body, press the right mouse button and select the option Insert into New Part. Select the cavity side body and follow the same steps.

1 Core extraction Tampere University of Technology Tuula Höök Theoretical background CAD tools in the exercise Cores 3 Mould structure Manufacturability Steps to follow Take the model start_cores_3_core.sldprt and the model start_cores_3_cavity.sldprt or the model start_with_tooling.sldprt. If you use the latter file, you need to save the core and cavity sides of the part into separate files before starting to work with them. Select the core side body, press the right mouse button and select the option Insert into New Part. Select the cavity side body and follow the same steps. Continue by viewing the core and cavity side from the machining and moulding or casting points of view. Select the details, which: are difficult to machine as inseparable part of the mould or die cavity will most likely wear or break during the moulding or casting process prevent the mould opening and / or the part ejection The first two details are typically some narrow projections or features, which separate from the rest of the cavity with a narrow recess. (See images.) The details, which prevent the mould opening and/or part ejection, require a moving core. Surface Modelling Offset Surface Ruled Surface Extended Surface Extruded Surface Surface Trim Surface Knit Solid Modelling Tools Split Combine Revolved Boss/Base Revolved Cut Fillet Insert Part When ever there are problems in using these tools, open SolidWorks help and try to find the solution there. Figure 1: Mould cavity with narrow and high projection and features, which separate from the rest of the cavity with very narrow recessions. Cores 3-1

Figure 2: A high projection in the middle of the mould cavity. Typical example of a place, where it is necessary to extract a fixed core as a separate piece.

Another option is to separate the cores by splitting with surfaces. Try both options. Split the fixed cores with surfaces 1.

The base extends through the cavity plate. It needs to have some securing element. Securing element can be simply a tapered face.

2 Figure 2: A high projection in the middle of the mould cavity. Typical example of a place, where it is necessary to extract a fixed core as a separate piece. SolidWorks has a special tool for the core extraction purpose. The tool is Core and it is located within the mould tools. One option is to separate the cores with this tool. Another option is to separate the cores by splitting with surfaces. Try both options. Split the fixed cores with surfaces 1. Prepare offset surfaces from the outer surfaces of the feature you wish to extract as a separate fixed core. The offset distance should be 0 mm. 2. Extend the surface to shape the core base. The base extends through the cavity plate. It needs to have some securing element. Securing element can be simply a tapered face. The offset surfaces method is practical if you wish to prepare tapered cores. Another basic option is to use a core with a straight base and a flange as the securing element, but with the type of core as prepared in this example, the tapering option is more practical. 3. Split the mould plate with the formed surface body. Figure 3: Left: The fixed core in the middle of the mould cavity with the offset surface. Middle and right: Surface extends to be used in cutting the mould plate with the core shapes. There will be one round core in both mould halves. Use some securing element on the top of the core. The finished cores will look like ones in the figure 4 next page. There is no need to prepare any fastening elements like flange in addition to the tapered shapes. The mould or die back plate will secure the cores tightly. Pay attention to the securing elements in the round cores. Cores 3-2

Moving cores Moving cores are extracted with the similar way as the fixed cores. There are no special tricks.

The core moving mechanisms require different shaping methods, but these are discussed later in the moving core mechanism exercises. In this part the moving core consists of two halves.

With this tool you can mate the added part like in an assembly. The mating tools will appear on the screen after you have selected the part to be inserted.

3 Moving cores Moving cores are extracted with the similar way as the fixed cores. There are no special tricks. The moving cores need a slide mechanism, a core pulling cylinder or some other construction, but the basic technique in extracting the cores is similar. The core moving mechanisms require different shaping methods, but these are discussed later in the moving core mechanism exercises. In this part the moving core consists of two halves. Mould core and cavity part have the similar moving core shape. Extract them both and combine together as one solid body. Use the Part tool under the Insert menu. With this tool you can mate the added part like in an assembly. The mating tools will appear on the screen after you have selected the part to be inserted. The moving core will look like the one in the image on the right. Figure 4: Left: A surface for splitting one half of the moving core body from the mould core side. Right: The combined moving core with both of the halves together. Shaped core end When two cores come together from both mould halves, it is sometimes good to secure the core ends together by shaping core ends to form interlocking surfaces. This technology is presented in the figure 5 below. Figure 5: Interlocking core ends. Cores 3-3

CAD tools quick guide Offset Ruled Surface Extend CAE DS Mould

result can be a set of twisted surfaces.

4 CAD tools quick guide Offset Ruled Surface Extend CAE DS Mould and Die Design Exercises This tool prepares an offset surface from an existing surface. If the curvature is too small compared to the wall thickness the result can be a set of twisted surfaces. It is also possible that in this case it is not possible to form the offset surface at all. With this tool you can prepare a swept or an extruded surface from part edges. You have different options in guiding the surface. With this tool you can extend an existing surface. The result is a single surface body. The extension continues the shape and direction of the original surface. Cores 3-4

Extrude Trim Knit Insert Features Fillet CAE DS Mould and Die

sketch. You can define a draft angle to the extrusion.

The tool requires two surfaces, a surface and a plane or a

A combination of a surface and a solid will not do.

This tool knits two or more separate surface bodies together and

5 Extrude Trim Knit Insert Features Fillet CAE DS Mould and Die Design Exercises This tool makes a linear surface extrude from a sketch. You can define a draft angle to the extrusion. If no angle is defined, the extrusion takes the direction of a normal of the sketch plane. This tool trims a surface with another surface. The tool requires two surfaces, a surface and a plane or a surface and a sketch. A combination of a surface and a solid will not do. Solid is cut with Cut with surface -tool. This tool knits two or more separate surface bodies together and forms one knitted surface body. If the surfaces form a closed sphere, you can form a solid from these surfaces directly with the knitting tool. This tool rounds a corner in an existing single surface object. Cores 3-5

Insert Features Split Insert Features Combine Insert Boss/Base

This tool splits a solid body into several solid bodies.

separate files use them as part of the ongoing modelling.

Axis can be one of the sketch lines or a centerline.

6 Insert Features Split Insert Features Combine Insert Boss/Base Revolve Insert Cut Revolve CAE DS Mould and Die Design Exercises This tool splits a solid body into several solid bodies. You can either consume some of the resulting bodies; save them to separate files use them as part of the ongoing modelling. This tool combines a set of separate solid bodies into one single body. This tool revolves a sketched closed profile around an axis and forms a solid feature. Axis can be one of the sketch lines or a centerline. This tool prepares a cut by revolving a sketched closed profile around an axis. The axis can be one of the sketch lines or a centerline. Cores 3-6

straight core with a flange Learn to use surfaces for splitting solid bodies Accepted One extracted moving core and one extracted fixed core on both sides The cavity and core plates with cut holes

7 Insert Part Insert a part to an opened part as a separate body. Learning Objectives Evaluation criteria Learn to find the shapes, which will need a separate fixed and/or moving core Learn to see the optimal core shape Different basic core shapes: drafted and straight core with a flange Learn to use surfaces for splitting solid bodies Accepted One extracted moving core and one extracted fixed core on both sides The cavity and core plates with cut holes for the cores Roundings are at reasonable places CAD tools to learn Surface Modelling: Offset Surface, Ruled Surface, Extended Surface, Lofted Surface, Surface Trim, Surface Fill, Surface Knit, Fillet, Body Move/Copy Solid Modelling Tools: Split Excellent One extracted moving core and two extracted fixed cores: Two fixed cores on the cavity side and two fixed cores on the core side The cavity and core plates with cut holes for the cores Roundings are at reasonable places Cores 3-7

8 Cores 3-8

SolidWorks: Mirror, Revolve, and. Introduction to Robotics

SolidWorks: Mirror, Revolve, and Circular Pattern Introduction to Robotics Let s Review At this point we have learned the following: Extrude Boss/Base Extruded Cut Adding Relations and Dimensions Linear