Mastercam Version 9 SolidsTutorial - Part 7 doc

You will create this mold by adapting an imported solid model of the camera's cavity and core.. You will build on skills that you learned in previous chapters and learn new skills, such

7 Designing an Injection Mold for a

Camera

In this chapter, you will create a two-piece plastic injection mold for a camera You will create this mold by adapting an imported solid model of the camera's cavity and core

You will build on skills that you learned in previous chapters and learn new skills, such as:

Importing Parasolid® files Checking solids for error conditions Using translucent shading

Creating an operation history for an imported solid Renaming operations in the Solids Manager

Exercise 1 – Importing the camera files

In this exercise, you will import two solids, one that represents the camera cavity and the other that represents the camera core Each solid is

contained in a separate Parasolid® file You will merge both solids into

2 Set the construction color to light blue (number 11)

Tip: Choose Color from the Secondary Menu, enter 11 for Current color, and choose OK

3 Switch to wireframe display, if necessary

Tip: Choose Main Menu, Screen, Surf disp, Solids Select Wireframe and choose OK

4 Choose Main Menu, File, Converters, Parasld, Read file The

Specify File Name to Read dialog box opens

5 Open camera-cavity-mm.x_t from your working folder The Parasolid Read parameters dialog box opens

6 Clear the Edge curves check box When selected, this option

creates curves along all edges on the imported solid

7 Clear the Override file name check box

8 Check your settings against the following picture Make any necessary adjustments

9 Choose OK to import the file If prompted to delete the current part, choose No

10 Switch to Isometric view and fit the camera cavity to the screen Your part should look like the following picture

11 Press [Alt+S] to turn on shading Your part should look like the following picture

Importing the camera core

1 Set the construction color to light gray (number 7)

5 The system asks you if you want to delete the current part Choose

No to merge the core into the same file with the cavity Both

halves of the mold now display in the graphics window Each half

is a separate solid

6 Fit the geometry to the screen Your part should look like the following picture

7 To get a better view of the camera core, you will temporarily

blank the camera cavity Choose Main Menu, Screen, Blank

8 Select the camera cavity (light blue solid)

9 Turn off shading The graphics window now contains only the camera core, as shown in the following picture

10 Turn on shading and dynamically rotate the graphics view so that you can see the underside of the camera core Your part should look similar to the following picture

Viewing the two halves of the mold together

In order to see the void between the two halves of the shaded mold, you will turn on translucency

1 Return to Isometric view

2 The Blank function is still active Choose Unblank from the

Blank menu The system displays the blanked camera cavity

3 Select the light blue solid to unblank it, and choose Backup

4 Choose the Screen-Surf Disp-Shading toolbar button The

Shading Settings dialog box opens

5 Select Translucent at the bottom of the dialog box, and choose

OK to close the dialog box Your part should look like the

following picture

6 Save the file as camera-mm.mc9 in your working folder

Exercise 2 – Checking the cavity and core for errors

In this exercise, you will use the Check Solid function to analyze the solid cavity and core for error conditions that may require repair or

reconstruction This tool is particularly useful for checking the integrity of imported solids If Mastercam detects errors, such as self-intersecting bodies, wireframe edges intersecting faces at locations other than at

vertices, etc., it describes them and highlights their location in the model

1 Choose Main Menu, Analyze, Surfaces, Check solid The

Check Solid dialog box opens

2 Choose Perform Check The Pick Solid Entity menu displays

3 Toggle Solids to Y and all other Yes/No options to N

4 Select the camera cavity (light blue solid) Mastercam reopens the Check Solid dialog box and reports the number of errors that it detected In this case, no errors were detected

5 Choose OK to clear the message, then choose Perform Check

again

6 Select the camera core (light gray solid) Again, Mastercam reports that no errors were detected

7 Choose OK twice to clear the message and close the dialog box

Exercise 3 – Creating an operation history for the

camera cavity

Imported solids are referred to as bricks because they contain no record of how they were constructed However, you can use the Find Features function to create an operation history for an imported solid You can locate holes and fillets in a model and either remove the detected features

or create operations based on them In this exercise, you will create an operation history for the camera cavity

Renaming the base operations

Before you work with the camera cavity, you will rename the import operations to better organize the models

1 Press [Alt+Y] to open the Solids Manager then expand each solid There are two solids listed for this file, one for the camera cavity and one for the core Under each solid, there is a base operation titled “Body.” You cannot delete or edit this operation

2 Click on Body for the first solid in the list Mastercam highlights

the camera cavity in the graphics window

3 With Body selected, right-click to display a menu, and choose

Rename The name field becomes editable

4 Type Cavity, and press [Enter]

5 Repeat steps 2 through 4 to name the second “Body” operation

using the name Core The Solids Manager should look like the

following picture

6 Choose OK to close the Solids Manager

Finding holes on the camera cavity

In this exercise, you will locate holes on the camera cavity and will create operations based on these holes Mastercam defines the new operations as extruded cuts and creates the associated geometry (circles) required to define the holes You will set a unique

construction color and level for this geometry, which better organizes the model and makes it easy to locate the geometry for editing

purposes later

1 Blank the camera core by pressing [Alt+F7] and selecting the light gray solid

2 Press [Alt+Y] to open the Solids Manager

3 Right-click in the solid list area and choose Solids, Find features

The Find Features dialog box opens

Note: Mastercam will look for features on the camera cavity because it is currently the only visible solid If the camera core had also been visible, you would have been prompted to select the solid on which to find features

4 In the Feature section of the dialog box, select Holes and in the

Function section of the dialog box, select Create operations

5 Enter 50 for Maximum Radius

6 Check your settings against the following picture Make any necessary adjustments

7 Choose New Geometry Attributes The New Geometry

Attributes dialog box opens Here you will customize the curve geometry that Mastercam will create to define the holes

8 Enter 0 for Offset This value determines the distance the circles,

which define the holes, will be created from the solid

9 Enter 5 (dark purple) for Color

10 Enter 2 for Level

11 Check your settings against the following picture Make any necessary adjustments

12 Choose OK twice to close the New Geometry Attributes and Find

Features dialog boxes Mastercam processes the search, creates the operations, and opens the Solid Feature Detection dialog box

13 Choose OK in the Solid Feature Detection dialog box This

reopens the Solids Manager dialog box

Mastercam found eight holes and created five operations Four holes represent the spot faces These are blind holes, in which the cuts do not penetrate the entire solid Mastercam creates a separate operation for blind holes The other four holes represent the bolt holes These are through-holes, which cut through the entire cavity Mastercam grouped these cuts together in one operation because the “Combine operations” option was selected on the Find Features dialog box This option applies only to through-holes

Renaming the cut operations

You will rename the Extrude Cut operations to better organize the model in the Solids Manager

1 Click on each Extrude Cut operation in the list Mastercam

highlights the corresponding holes in the model The first four Extrude Cut operations correspond to the spot faces The last Extrude Cut operation corresponds to the four bolt holes

2 Rename the first Extrude Cut operation as Spot Face 1

Tip: Right-click on the operation, choose Rename, type the new name, and

press [Enter]

3 Rename the three remaining spot face operations in order

4 Rename the last Extrude Cut operation as Bolt Holes The Solids

Manager should look like the following picture

Exercise 4 – Modifying the spot faces

Now that you have created an operation history for the camera cavity, you can edit the operations In this exercise, you will modify the parameters and geometry that define the cut operations that correspond to the camera cavity’s spot faces

Shortening the cut distance for the spot faces

In order to change the cut distance for the spot faces, you will edit the parameters of the Spot Face operations

1 Expand Spot Face 1

2 Double-click on Parameters The Extrude Chain dialog box

opens

3 Enter 12 for Distance, and choose OK Mastercam returns to the

Solids Manager and marks the operation dirty

4 Repeat steps 1 through 3 for the three remaining spot faces

5 Choose Regen All to incorporate the change in the model

6 Choose OK to close the Solids Manager

Increasing the size of the spot faces

In order to change the size of the spot faces, you will edit the

associated geometry (circles), which define the spot face cuts

1 Turn off shading

2 Choose Main Menu, Analyze, Only, Arcs

3 Select the dark purple circle at position 1, as shown in the

following picture

1

4 In the prompt area, Mastercam displays data for the circle On the

Analyze Entity menu, toggle Edit to Y The data now displays in

the Analyze dialog box where some of the data is editable

5 Enter 24 for Diameter, and choose OK to close the dialog box

6 Repeat steps 3 through 5 for the three remaining spot face circles,

as shown at positions 2, 3, and 4 in the following picture

2

3

4

Exercise 5 – Creating curve geometry for a sprue

hole and a gate

In this exercise, you will create curve geometry to represent a sprue hole and a gate A gate allows molten plastic to be injected into the mold, and a sprue hole allows air to escape from the mold as the plastic fills the void between the mold halves In a later exercise, you will use the curve

geometry to cut the sprue hole and the gate in the solid model

Managing geometry levels

In this exercise, you will name the levels on which you have created part geometry in previous exercises

1 Choose Level from the Secondary Menu The Level Manager

opens

2 In the Main Level section of the dialog box, enter 1 for Number and Camera core/cavity for Name

3 Enter 2 for Number and Cavity hole geometry for Name

4 Enter 3 for Number and Sprue hole/gate geometry for Name

5 Make level 2 invisible by clearing the red check mark in the Visible column for this number

6 Choose OK to close the Level Manager

Extracting an edge curve

When you imported the camera files into Mastercam, you had the option to create curves along all edges of the solids You did not select this option, however, because it would have resulted in the creation of a lot of unnecessary geometry You will now extract a single edge curve, which you will use to create the sprue hole and gate

1 Unblank the camera core

Tip: Choose Main Menu, Screen, Blank, Unblank Select the camera core and choose Backup

2 Set the construction color to light green (number 10)

3 Choose Main Menu, Create, Curve, One edge, From solid

4 Toggle Edges to Y and all other Yes/No options to N

5 Select the center edge at the position shown in the following picture

6 Mastercam creates a curve (line) to match the geometry along this

edge Choose Done to exit the function

Offsetting the edge curve

You will offset the edge curve in order to create a line parallel to it Later, you will use this line to position the sprue hole and gate You will offset the edge curve in the Top plane at a zero depth, which is the plane where the mold halves meet

1 Choose Cplane, Top

2 Choose Main Menu, Create, Line, Parallel, Side/dist

3 Select the green edge curve to offset

4 Set the offset direction by clicking to the left of the edge curve (toward the void in the camera model)

Parallel line

Extracted edge curve

Creating a circle for the sprue hole

You will create a 4.5-millimeter diameter circle at the midpoint of the parallel line In a later exercise, you will use this circle to cut the sprue hole

1 Choose Main Menu, Create, Arc, Circ pt+dia

2 In the prompt area, type 4.5 and press [Enter]

3 Choose Midpoint from the Point Entry menu

4 Select the parallel line Mastercam creates a circle that defines the sprue hole

5 Choose Backup to exit the function

6 Zoom in on the section of the mold that contains the newly

created circle Your part should look like the following picture

Sprue hole circle

Creating a circle for the gate

You will create a 2-millimeter diameter circle at the midpoint of the parallel line This circle will be created in the Side construction plane; therefore, it will be perpendicular to the sprue hole circle, which was created in the Top construction plane In a later exercise, you will use the 2-millimeter circle to cut the gate

1 Choose the Cplane-Side toolbar button

2 Set the construction depth to 77 millimeters

Tip: Choose Z from the Secondary Menu, type 77, and press [Enter] As you

type, the value displays in the prompt area

3 Choose Circ pt+dia from the Arc menu

4 In the prompt area, type 2 and press [Enter]

5 Choose Midpoint from the Point Entry menu

6 Select the parallel line Mastercam creates a circle that defines the gate

7 Press Backup to exit the function

Gate circle

Deleting the reference geometry

You no longer need the extracted edge curve or the parallel line, so you will delete them

1 Choose Main Menu, Delete, Only, Lines

2 Select the extracted edge curve and the parallel line at the positions shown in the following picture

Note: A section of each line has been thickened to help you identify the correct lines to select Mastercam deletes each line as you select it

3 Choose Backup to exit the function

Exercise 6 – Adding the sprue hole and the gate to

Cutting the sprue hole in the core

1 Zoom in closely on the sprue hole and gate circles

2 Choose Main Menu, Solids, Extrude

3 Select the 4.5-millimeter diameter circle, as shown in the

following picture

4 Choose Done

5 Make sure that the extrusion direction arrow points up If it does