Mastercam Version 9 SolidsTutorial - Part 6 pdf

Up to this point in the tutorial, you have not been concerned with the construction settings because Mastercam uses the plane and depth of the underlying curve geometry when constructing

6 Designing a Windshield for a Toy

Race Car

In this chapter, you will create a solid model of a windshield for a toy car You will build this model from existing wireframe geometry and from circles that you create to define the windshield’s curved shape

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

Creating a base solid (Loft) Changing the light intensity on the shaded solid Removing select defining curves from the solid

Exercise 1 – Defining the windshield’s shape

In this exercise, you will create circles along a spline at six pre-defined points The circles will form cross-sections of the windshield and define the windshield’s basic shape Before you create the circles, however, you will set the construction plane (Cplane) and construction depth (Z)

Up to this point in the tutorial, you have not been concerned with the construction settings because Mastercam uses the plane and depth of the underlying curve geometry when constructing solids However,

Mastercam creates wireframe geometry (lines, arcs, splines) on the plane and at the depth that you define

Note: The current construction settings are reflected on the Cplane and Z buttons on the Secondary Menu

Setting the construction plane and depth

You will set the construction plane to (right) side view and set the depth based on the midpoint of an existing line

1 Open windshield-wireframe-mm.mc9 from your working folder

2 Choose the Cplane button on the Secondary Menu

3 Choose Side from the Construction Plane menu Mastercam

changes the construction plane to side view

4 Choose the Z (depth) button on the Secondary Menu Mastercam

displays the Point Entry menu

5 Position the cursor halfway along the line shown in the following picture

6 When the cursor changes to an open square and Mastercam

highlights the Midpoint option on the Point Entry menu, click to select this position Mastercam sets the depth to match that of the midpoint of the selected line

Note: For Mastercam to detect the point, the AutoCursor must be turned on For more information, see “Turning on the

AutoCursor and AutoHighlight features” in Exercise 2 of Chapter

2

Creating a circle

You will create a circle by defining three unique edge points

1 Choose Main Menu, Create, Arc, Circ 3 pts

2 Choose Point from the Point Entry menu, and select the green

point at the position shown in the following picture

3 Choose Endpoint from the Point Entry menu, and select the

brown line shown at position 1 in the following picture

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4 Choose Endpoint again, and select the brown line shown at

position 2 in the previous picture Mastercam fits a circle to these three points at a depth of –41.870 millimeters

5 Press [Esc] to exit the function

Copying the circle

You will now copy the circle to a second point along the windshield geometry Before you do so, you will change the construction plane

to 3D, which lets you create geometry in unrestricted 3D space The circle will be copied to the depth of the translation point that you enter and will remain parallel to the plane defined by the original circle (side view)

1 Choose the blue Cplane-3D toolbar button

2 Choose Main Menu, Xform, Translate

3 Select the circle you just created then choose Done

4 Choose Between pts from the Translate Direction menu

5 Define the “from” translation point by selecting the point entity at position 1, as shown in the following picture

Note: When the cursor detects the point entity, the system highlights the Point option on the Point Entry menu

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6 Define the “to” translation point by selecting the point entity at position 2, as shown in the previous picture The Translate dialog box opens

7 Select Copy as the operation type Check your settings against the

following picture

8 Choose OK to copy the circle to position 2 Your part should look

like the following picture

Copying the circle to the remaining points

When you perform an Xform (transform) operation, the entities that you select to transform turn red, indicating they are a group The new entities turn purple, indicating they are the result of the operation These temporary color/group designations allow you to select

geometry quickly when performing multiple transform operations on the same geometry

1 From the Translate menu, choose Result Mastercam selects the

second circle, which resulted from the previous operation

2 Choose Done to end the selection

3 Choose Between pts from the Translate Direction menu

4 Define the “from” translation point by selecting the point entity at position 1, as shown in the following picture

5 Define the “to” translation point by selecting the point entity at position 2, as shown in the previous picture The Translate dialog box opens

6 Choose OK to copy the circle There are now three circles along

the windshield geometry

7 Repeat steps 1 through 6 three more times, selecting the three remaining points in order until you have created a total of six circles

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

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9 After you have created the six circles, press [Esc] to exit the function

10 Choose the Screen-Clear Colors toolbar button to remove the

group/result colors from the last two circles

Exercise 2 –Creating the windshield’s solid body

In this exercise, you will use the Loft function to create a solid based on the circles that you defined in the previous exercise The system creates a lofted solid by transitioning between two or more selected closed chains

of curves, which define the cross-sections of the solid

1 Choose Main Menu, Solids, Loft

2 Select the circle at position 1 in the following picture Note the direction of the arrow that displays on the chain It is important that the chaining direction be the same for all the chains that you select

Note: The chaining direction determines how the system transitions between chains when building the lofted solid It does not matter which direction the arrows point, just that they point in the same direction

3 Select the remaining circles in order from positions 2 through 6,

as shown in the previous picture If necessary, choose Reverse to

correct the chaining direction before selecting the next chain

4 After you have selected all six chains, choose Done The Loft

Chain dialog box opens

5 Enter Windshield Body for the operation name

6 Check your settings against the following picture, then choose

OK to create the solid

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

8 Choose Main Menu, File, Save and save the file as

windshield-solid-mm.mc9 in your working folder

Exercise 3 – Refining the windshield’s shape

In this exercise, you will trim the front and bottom of the windshield to make it more aerodynamic

Preparing the part (setting levels, hidden lines, etc.)

1 Choose the Level button on the Secondary Menu The Level

Manager opens

2 Make level 4 visible by clicking in the Visible column for this

level Level 4 contains two rectangles, which you will use to trim the windshield’s shape

3 Choose OK to close the Level Manager

4 Press [Alt+S] to turn off shading

5 Press [Alt+F1] to fit the geometry to the screen

6 Choose Main Menu, Screen, Surf disp, Solids The Solids

Display dialog box opens

7 Turn on hidden lines by selecting Hidden and Show Hidden Lines

8 Check your settings against the following picture, and choose OK

to close the Solids Display dialog box

Your part should look like the following picture

Trimming the front of the windshield

You will remove material from the windshield by extruding two chains, one nested within the other, as a cut in both directions

1 Choose Main Menu, Solids, Extrude

2 Choose Chain, Options The Chaining Options dialog box opens

3 Select Color mask and choose OK When this option is turned

on, you can select only geometry that is the same color as the first entity that you select

4 Choose the Screen-Clear Colors toolbar button

5 Select the brown geometry at positions 1 and 2, as shown in the following picture The chains lie in the same plane, and chain 1 is nested within the boundary of chain 2

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Note: Chain 1 contains a branch point where the brown and red entities intersect Because the color mask was turned on and the first entity that you selected was brown, the system ignored the red entities and followed the brown line at the branch point If you had not used the color mask, the system would have stopped the chain at the branch point and prompted you to select the next entity manually

6 Choose Done to end the selection

7 Choose Done to set the extrusion direction The Extrude Chain

dialog box opens

Note: The extrusion direction does not matter since you will extrude the chains in both directions

8 Enter Trim Front for the operation name

9 Select Cut Body

10 Select Extend through all

11 Select Both directions

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

13 Choose OK to create the cut

14 Turn on shading Your part should look like the following picture

Changing the shading settings

You will view the results in top view First, however, you will change the shading settings to reduce the glare from the light that shines directly on the part in this view

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

Shading Settings dialog box opens

2 Choose the Lights button at the bottom of the dialog box The

Lighting dialog box opens

3 Choose the middle bulb The Lighting Options dialog box opens

4 Enter 0.5 for Light intensity

5 Choose OK three times to close the dialog boxes and return to the

7 Repeat steps 1 through 6 to return the center bulb to full intensity (1.0)

8 Return to Isometric view

Trimming the bottom of the windshield

You will extrude a single chain of curves in both directions to cut the bottom of the windshield and make it flat

1 Choose Extrude from the Solids menu

2 Select the blue line at the position shown in the following picture

3 Choose Done to end the selection

4 Choose Done to accept the default extrusion direction The

Extrude Chain dialog box opens

5 Enter Trim Bottom for the operation name

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

7 Choose OK to create the cut Your part should look like the

following picture

Exercise 4 – Making the windshield more

aerodynamic

In this exercise, you will make the windshield more aerodynamic by increasing the slope of the front of the windshield To do so, you will delete two of the circles that define the body (cross-sections) of the

3 Double-click the Geometry icon for the Windshield Body

operation The Solid Chain Manager lists the six chains used to define the lofted solid in the order in which they were selected

4 Select Chain 2 and Chain 3 from the list The system highlights

the corresponding chains in the graphics window

Tip: To select multiple items in the list, hold down the [Ctrl] key on your keyboard and click on the items to select

Chain 2 Chain 3

5 With your cursor positioned over the selected chains in the list, right-click to open the following menu

6 Choose Delete Chain Mastercam deletes Chains 2 and 3 from

the list and renumbers the remaining chains

7 Choose OK to close the Solid Chain Manager

8 Choose Regen All to rebuild the solid using four defining chains

9 Suppress the Trim Front and Trim Bottom operations Your part

should look like the following picture

Tip: To suppress an operation, right-click on it, then choose Suppress The

operation icon will turn gray

The lofted solid now transitions from the first circle to the fourth circle, which creates a steeper slope

10 Unsuppress the Trim Front and Trim Bottom operations

Tip: To unsuppress an operation, right-click on it, then choose Suppress The

operation icon will no longer be gray

11 Choose OK to close the Solids Manager Your part should look

like the following picture

Exercise 5 – Hollowing out the windshield

In this exercise, you will hollow out the windshield To do so, you will use the Shell function, which you learned about in Exercise 6 of Chapter 3 To make it easier to select the correct face to leave open, you will use the Hide function to remove all geometry from the screen except for the solid

Hiding the curve geometry

When using the Hide function, you select the geometry that you want

to keep visible on the screen Mastercam hides all unselected entities

1 Press [Alt + E] to access the Hide function A selection menu displays

2 Choose All, Solids, Done Only the solid remains visible in the

graphics window

Shelling the solid

1 From the Solids menu, choose Shell

2 Toggle Faces and From Back to Y and all other Yes/No options

5 Select Inward for Shell Direction

6 Enter 1.32 for Shell Thickness

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

8 Choose OK to hollow out the windshield

9 Dynamically rotate the windshield to view its underside Your part should look similar to the following picture

Exercise 6 – Smoothing the outside edges and nose

of the windshield

In this exercise, you will fillet the outside edges and nose of the

windshield You will use a constant radius for the outside edges and a variable radius for the nose

Filleting the windshield’s outside edges

1 Return to Isometric view

2 Fit the geometry to the screen

3 Turn off shading

4 Return the solid to wireframe display

Tip: Choose Main Menu, Screen, Surf disp, Solids On the Solids Display dialog box, select Wireframe, and choose OK

5 Choose Main Menu, Solids, Fillet

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

7 Select the two outside edges at the positions shown in the

following picture

Note: In the picture, a section of each line has been thickened to make it easier to identify the correct edges to select

8 Choose Done The Fillet Parameters dialog box opens

9 Enter Fillet Sides for the operation name

10 Enter 15 for Radius

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

12 Choose OK to close the Fillet Parameters dialog box Your part

should look like the following picture

Filleting the windshield’s nose

1 Set the graphics view to Side

2 Fit the geometry to the screen

3 Change to hidden line display but do not show the hidden lines

Tip: Choose Main Menu, Screen, Surf disp, Solids On the Solids Display dialog box, select Hidden, clear Show Hidden Lines, then choose OK

4 Choose Main Menu, Solids, Fillet

5 Select the edges at positions 1, 2, and 3, as shown in the following picture

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6 Choose Done The Fillet Parameters dialog box opens

7 Enter Fillet Nose for the operation name

8 Select Variable Radius and Smooth

Note: For more information about the Smooth option, see

“Setting fillet parameters” in Exercise 4 of Chapter 2

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

10 Expand the three edges in the edge list section of the dialog box There are two vertices, or endpoints, listed for each edge