Whiffle Ball tutorial

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Topic
Tutorial
Product design
Level
Beginner
Time to complete
30 minutes
Authors
r-frank and vocx
FreeCAD version
0.17 and above
Example files
WhiffleBall_Tutorial_FCWiki.FCStd
See also
None

Introduction

This tutorial was originally written by Roland Frank (†2017, r-frank), and it was rewritten and illustrated by vocx.

This tutorial is here to teach you how to use the Part Workbench.

The Part Workbench was the first workbench developed. It provides the basic geometrical elements that can be used as building blocks for other workbenches. The Part Workbench is meant to be used in a traditional constructive solid geometry (CSG) workflow. For a more modern workflow using sketches, pads, and features, use the PartDesign Workbench.

You will practice:

inserting primitives
changing parameters of those primitive objects
modifying their placement
doing boolean operations

Final model of the wiffle ball

Setup

1. Open FreeCAD, create a new empty document with File → New, and switch to the Part Workbench.

1.1. Press the

View isometric button, or press 0 in the numerical pad of your keyboard, to change the view to isometric to visualize the 3D solids better.

1.2. Press the

View fit all button whenever you add objects in order to pan and zoom the 3D view so that all elements are seen in the view.

1.3. Hold Ctrl while you click to select multiple items. If you selected something wrong or want to de-select everything, just click on empty space in the 3D view.

Insert primitive cubes

2. Insert a primitive cube by clicking on Box.

2.1. Select Cube in the tree view.

2.2. Change the dimensions in the Data tab of the property editor.

2.3. Change Length to 90 mm.

2.4. Change Width to 90 mm.

2.5. Change Height to 90 mm.

3. In the Data tab of the property editor, click on the Placement value so the ellipsis button ... appears on the right.

3.1. Press on the ellipsis to launch the Placement dialog.

3.2. Change the Translation values.

3.3. Change X to -45 mm.

3.4. Change Y to -45 mm.

3.5. Change Z to -45 mm.

3.6. Press the OK button to close the dialog.

4. Repeat the process, inserting a second, smaller cube by clicking on Box.

4.1. The second cube will be created with the same name, but with an additional number to distinguish the object.

4.2. Select Cube001 in the tree view, and change the dimensions and placement like with the previous object.

4.3. Change Length to 80 mm.

4.4. Change Width to 80 mm.

4.5. Change Height to 80 mm.

4.6. Open the Placement dialog.

4.7. Change X to -40 mm.

4.8. Change Y to -40 mm.

4.9. Change Z to -40 mm.

4.10. Press the OK button to close the dialog.

Change visual properties

5. The previous operations create a smaller cube inside a bigger cube. To visualize this, we can modify the View properties in the property editor.

5.1. Select Cube001, the smaller cube, in the tree view, and change the color. In the View tab, click on the Shape Color value to open the Select color dialog, then choose a green color; also change the value of Line Width to 2.0.

5.2. Select Cube, the larger cube, in the tree view. In the View tab, change the value of Transparency to 70.

Solid cube inside another solid cube

Insert primitive cylinders

6. Insert a primitive cylinder by clicking on Cylinder.

6.1. Select Cylinder in the tree view.

6.2. Change the dimensions in the Data tab of the property editor.

6.3. Change Radius to 27.5 mm.

6.4. Change Height to 120 mm.

6.5. Open the Placement dialog.

6.6. Change Z to -60 mm.

6.7. Press the OK button to close the dialog.

7. Repeat the process, inserting a second cylinder by clicking on Cylinder.

7.1. The second cylinder will be created with the same name, but with an additional number to distinguish the object.

7.2. Select Cylinder001 in the tree view, and change the dimensions and placement like with the previous object.

7.3. Change Radius to 27.5 mm.

7.4. Change Height to 120 mm.

7.5. Open the Placement dialog.

7.6. Change Y to 60 mm.

7.7. Change the Rotation to Rotation axis with angle; Axis to X (by setting the X, Y and Z values of the axis inputboxes to 1, 0 and 0 respectively), and Angle to 90 deg.

7.8. Press the OK button to close the dialog.

8. Insert another cylinder. This time create a duplicate so that the radius and height don't have to be changed, only its placement.

8.1. Select Cylinder001 in the tree view, and go to the menu Edit → Duplicate selection. This will create Cylinder002.

8.2. Open the Placement dialog.

8.3. Change X to -60 mm, and change Y back to 0 mm.

8.4. Change the Rotation to Rotation axis with angle; Axis to Y, and Angle to 90 deg.

8.5. Press the OK button to close the dialog.

Change visual properties

9. The previous operations create three cylinders that intersect with each other, and also intersect the cubes. To visualize this better we can modify the View properties in the property editor.

9.1. Select Cube001, the smaller cube, in the tree view, and change the transparency. In the View tab, change the value of Transparency to 70.

9.2. Select Cylinder, in the View tab, click on the Shape Color value to open the Select color dialog, then choose a red color.

9.3. Select Cylinder001, in the View tab, click on the Shape Color value to open the Select color dialog, then choose a blue color.

9.4. Select Cylinder002, in the View tab, click on the Shape Color value to open the Select color dialog, then choose a pink color.

9.5. Select the three cylinders, in the View tab also change the value of Line Width to 2.0.

Solid cylinders that intersect themselves and the solid cubes.

Fuse and cut

10. In the tree view, select Cube001 (the inner, smaller cube), and the tree cylinders, then press Fuse. This will create a Fusion object.

11. Then perform a boolean cut of the Cube (larger cube) and the new Fusion object.

11.1. In the tree view select Cube first, and then Fusion.

11.2. Then press

Cut. This will create a Cut object.

Note: the order in which you select the objects is important for the cut operation. The base object is selected first, and the subtracting object comes at the end.

11.3. If the colors look strange, select the new Cut object, go to the View tab, click on the Shape Color value to open the Select color dialog, then choose a gray color; also change the value of Line Width to 2.0.

Hollow shape produced from cutting a cube and three cylinders from a bigger cube.

Insert primitive cubes to cut the corners of the partial solid

Now we'll create more cubes that will be used as cutting tools to trim the corners of the previously obtained Cut object.

12. Click on Box.

12.1. Select Cube002 in the tree view, and change the dimensions and placement.

12.2. Change Length to 140 mm.

12.3. Change Width to 112 mm.

12.4. Change Height to 112 mm.

12.5. Open the Placement dialog.

12.6. Change X to -70 mm.

12.7. Change Y to -56 mm.

12.8. Change Z to -56 mm.

12.9. Press OK.

13. Click on Box.

13.1. Select Cube003 in the tree view, and change the dimensions and placement.

13.2. Change Length to 180 mm.

13.3. Change Width to 180 mm.

13.4. Change Height to 180 mm.

13.5. Open the Placement dialog.

13.6. Change X to -90 mm.

13.7. Change Y to -90 mm.

13.8. Change Z to -90 mm.

13.9. Press OK.

We'll duplicate the previous two objects again to use once more as cutting objects.

14. Select only Cube002 in the tree view, and go to Edit → Duplicate selection. This will create Cube004.

15. Select only Cube003 in the tree view, and go to Edit → Duplicate selection. This will create Cube005.

16. To visualize this better we can modify the View properties in the property editor.

16.1. Select the Cut object, in the View tab, click on the Shape Color value to open the Select color dialog, then choose a blue color.

16.2. Select all new cubes, Cube002, Cube003, Cube004, and Cube005, in the View tab, change the value of Transparency to 80.

Additional external cubes that will be used as cutting objects for the internal solid.

Cutting the corners 1

17. In the tree view select Cube002 and Cube003.

17.1. Open the Placement dialog.

17.2. Tick the option Apply incremental changes; notice that all Translation values are reset to zeroes.

17.3. Change the Rotation to Rotation axis with angle; Axis to X, and Angle to 45 deg, then click on Apply. This will apply a rotation around the X-axis, and will reset the Angle field to zero.

17.4. Change the Rotation again, now Axis to Z, and Angle to 45 deg, then click on Apply. This will apply a rotation around the local Z-axis, and will reset the Angle field to zero.

17.5. Click on OK to close the dialog.

18. In the tree view de-select the objects; then select Cube003 first, the bigger cube, and then Cube002, the smaller cube.

18.1. Then press

Cut. This will create Cut001. This is a hollowed body which intersects the initial Cut only at certain corners.

19. To visualize this better we can modify the View properties in the property editor.

19.1. Select Cube004 and Cube005, in the View tab, then change the value of Visibility to false, or press Space in the keyboard.

19.2. Select Cut001, click on the Shape Color value to open the Select color dialog, then choose a red color; also change the value of Transparency to 90.

A rotated, hollowed solid, which will be used as a cutting object for some corners of the internal solid.

Cutting the corners 2

20. In the tree view select Cut001, in the View tab, change the value of Visibility to false, or press Space in the keyboard.

21. In the tree view select Cube004 and Cube005, in the View tab, change the value of Visibility to true, or press Space in the keyboard.

21.1. Open the Placement dialog.

21.2. Tick the option Apply incremental changes; notice that all Translation values are reset to zeroes.

21.3. Change the Rotation to Rotation axis with angle; Axis to X, and Angle to 45 deg, then click on Apply. This will apply a rotation around the X-axis, and will reset the Angle field to zero.

21.4. Change the Rotation again, now Axis to Z, and Angle to -45 deg, then click on Apply. This will apply a rotation around the local Z-axis, and will reset the Angle field to zero.

21.5. Click on OK to close the dialog.

22. In the tree view de-select the objects; then select Cube005 first, the bigger cube, and then Cube004, the smaller cube.

22.1. Then press

Cut. This will create Cut002. This is a hollowed body which intersects the initial Cut only at certain corners.

23. To visualize this better we can modify the View properties in the property editor.

23.1. Select Cut002, click on the Shape Color value to open the Select color dialog, then choose a pink color; also change the value of Transparency to 90.

A rotated, hollowed solid, which will be used as a cutting object for some corners of the internal solid.

Finishing the model

24. Make sure all objects are visible. In the tree view select all objects, in the View tab, change the value of Visibility to true, or press Space in the keyboard.

The internal hollowed solid, together with the external objects which will be used to cut it.

25. In the tree view de-select the objects; then select Cut first, and then Cut001.

25.1. Then press

Cut. This will create Cut003.

The internal hollowed solid, cut by Cut001.

26. In the tree view de-select the objects; then select Cut003 first, and then Cut002.

26.1. Then press

Cut. This will create Cut004. This is the final object.

26.2. Select Cut004, click on the Shape Color value to open the Select color dialog, then choose a green color; also change the value of Line Width to 2.0.

The internal hollowed solid, cut by Cut001 and Cut002. Final model.

27. Real objects don't have perfectly sharp edges or corners, so applying a fillet to the edges can be done to refine the model.

27.1. In the tree view, select Cut004 then press

Fillet.

27.2. In the Fillet edges task panel go to Selection, choose Select edges, and then press All. As Fillet type choose Constant radius, then set Radius to 1 mm.

24.3. Press OK. This will create a Fillet object.

27.4. In the View tab, change the value of Line Width to 2.0.

Final whiffle ball model with fillets applied to the edges.