Step 1: Create a Rectangle on the Main Plane

1. Hover your arrow over the top menu bar until you see the yellow Sketch prompt appear (Figure 4-11).

   

   Figure 4-11. Sketch prompt

2. Choose Sketch Rectangle (Figure 4-12).

   

   Figure 4-12. Choose the Sketch Rectangle option

3. Follow the prompt to click on the big blue grid (Figure 4-13).

   

   Figure 4-13. Click on blue grid

4. Click once to start the rectangle (Figure 4-14).

   

   Figure 4-14. Start the rectangle

5. Move your cursor and click again to stop (Figure 4-15).

   

   Figure 4-15. Click to stop

6. Select the green checkbox to exit (Figure 4-16).

Figure 4-16. Click the green box to exit

Step 2: Extrude the Rectangle into a 3D Object

1. Hover the cursor over the top menu bar and select Construct (Figure 4-17).

   

   Figure 4-17. Select the Construct option

2. Then select Extrude (Figure 4-18).

   

   Figure 4-18. Select the Extrude option

3. Follow the prompts to select your 2D rectangle (Figure 4-19), and then use the arrow by clicking and holding while moving your cursor (Figure 4-20).

   

   Figure 4-19. Select your rectangle

   

   Figure 4-20. Click and hold

4. Release, and you now have a box (Figure 4-21).

Figure 4-21. Your new box!

Congratulations—you are now a CAD modeler!

Take a few minutes right now to practice these two steps a few more times, using various sketch shapes and construction commands.

Now, let’s go through the details so we can become experts.

Step 3: Make Changes to the Model

You have a box. How do you select the elements of the box that you would like to alter?

1. To select an object, simply click on it (Figure 4-22).

   

   Figure 4-22. Click to select

2. To select a specific face, edge, or corner, click again on the element you wish to select (Figure 4-23).

   

   Figure 4-23. Click the element

3. To alter, hover over the gear icon and select a method to alter your selection (Figure 4-24).

   

   Figure 4-24. Select a method to alter

Spend a few minutes playing around here, to see if you can replicate the images in Figures 4-25, 4-26, and 4-27.

Figure 4-25. Test Object A

Figure 4-26. Test Object B

Figure 4-27. Test Object C

New

Starts a new file.

Open

Opens a preexisting file. You can also use this option to choose one of the thousands of models in the 123D online gallery.

Insert

Imports STL files from your online projects space or your computer into the current file.

You can also insert objects from the 123D Gallery, as well as some example files.

Import SVG…

Imports SVG files either as a sketch or a solid. These can be vector files you find online or create in other programs such as Adobe Illustrator, Corel Draw, or Inkscape, or higher-end design programs such as Autodesk Inventor, SolidWorks, or Rhino. Once imported, you can manipulate these files in 123D Design.

Save…

Saves your sketch, either in the cloud or to your computer.

Save a Copy…

Saves the current version of your design while keeping the original intact. Use this as a way to do rapid iterations. You have two options: Save “to my projects,” which will save your project to your 123D account in the cloud; and “to my computer,” which saves your project offline, to your own hard drive.

Export…

Save to STL, SAT, or create a 2D layout. STL files are the default file type for 3D CAD work. A 2D layout is historically a line drawing with measurements. In 123D, this option translates the file for you and saves it inside your projects area on 123Dapp.com. 2D layouts are very helpful when you’re building something and need a drawing file. (It may take a few minutes for the drawing to appear, so be patient.)

3D Print

Opens your file in 123D Meshmixer where you can check, heal, and support your file, and set it up for at-home 3D printing. You can also save it as an STL file and send it out for a 3D print after you’ve run it through a healing operation.

Exit

Closes 123D Design.

Undo/Redo

The left- and right-facing curved arrows (Figure 4-35) allow you to Undo and Redo actions, respectively.

Figure 4-35. The Undo and Redo arrows in 123D Design

Transform

The icon of a cube inside a dotted-line square (Figure 4-36) contains Transform tools you can use to move, rotate, and scale your object up or down. But you need to have an object in the workspace to transform! So let’s skip these tools for the moment.

Figure 4-36. Transform tools

Rectangle

The Rectangle is one of the tools you’ll use the most as you’re designing. To use it:

1. Select the Rectangle tool from the Sketch toolkit (Figure 4-39).

   

   Figure 4-39. The Rectangle tool in the Sketch toolkit

2. Select your sketch plane: the main plane or the face of an object.

3. Click once in the place where you’d like one corner of the rectangle to be. Move your mouse until the rectangle is the size you want, then click again to finish the shape (Figure 4-40).

Figure 4-40. A sketch of a rectangle on the main plane

You can also use the Rectangle tool to generate more complex shapes by layering different rectangles on top of each other. You can then add your choice of feature to create your 3D shape.

If you need to clean up the design, use the Trim tool (Figure 4-41) in the Sketch toolkit to trim overlapping lines and create a smooth shape.

Figure 4-41. The Trim tool

But you don’t have to: 123D Design allows you to create a complex 3D shape even if it’s not perfectly trimmed.

You can extrude an overlapped shape by selecting which parts you want or don’t want extruded.

Circle

To use the Circle tool:

1. Select the Circle tool from the Sketch toolkit (Figure 4-42).

   

   Figure 4-42. The Circle tool

2. Click on the main plane (the blue grid) where you’d like the center point of the circle to be (Figure 4-43).

   

   Figure 4-43. Click where center of the circle should be

3. Move your mouse away from the center point until the circle is the size you wish, and then click again to “set” that size. You can also type a specific dimension into the dialog box and then press the Enter key (Figure 4-44).

   

   Figure 4-44. Set the size of the circle

4. Click the checkmark to finish sketching your circle.

Ellipse

The Ellipse tool makes it easy to add a bit of an arc to a surface. You may find yourself using this tool frequently. The Ellipse tool is also helpful when doing the loft operation (shown below).

To use the Ellipse tool:

1. Select the Ellipse tool from the Sketch toolkit (Figure 4-45).

   

   Figure 4-45. The Ellipse tool

2. Click the plane where you want the center of the ellipse to be (Figure 4-46).

   

   Figure 4-46. Click where the center of the ellipse should be

3. Click again to designate the height or length of the ellipse (Figure 4-47).

   

   Figure 4-47. Set the first dimension of the ellipse

4. Click again to designate the remaining dimension (Figure 4-48).

Figure 4-48. Set the other dimension of the ellipse

Polygon

The Polygon tool allows you to create multisided shapes.

To use the tool:

1. Select the Polygon tool from the Sketch toolkit (Figure 4-49).

   

   Figure 4-49. The Polygon tool

2. Click on your sketching surface where you want the center of the polygon to be.

3. Move the mouse to the desired radius and click again.

4. To change the number of sides, press the Tab key and toggle between dialog boxes, and type in the number of sides you want. Then click again to end the sketch.

Polyline

Use the Polyline tool to create line segments that make up shapes. A line segment consists of a straight or curved line that joins two points. Once you’ve created a shape, you can apply a feature, such as extrusion or loft, to the shape you’ve created. The Polyline tool, a well as all other sketching tools, allows you to add a third dimension to your sketch and make precise shapes that can be fit together.

To use the Polyline tool:

1. Choose the Polyline tool from the Sketch toolkit (Figure 4-50).

   

   Figure 4-50. The Polyline tool

2. Click once where you’d like your line to start. Release the mouse, move your mouse to the location where you want your line to end, and click again.

3. To make multiple segments, move the mouse and click again.

4. To create an arc using the Polyline tool, hold down the left mouse button and drag, creating the radius of the arc.

OK, now it’s time to use the skills you’ve just learned to build something fairly simple.

Spline

Use the Spline tool when you want to make a freeform organic shape to extrude or revolve.

Think of splines this way: imagine that you have a board with nails in it and a string that you’re going to thread around the nails to make curves. Each click you make in the sketching space is like putting a nail in the board, and the software automatically curves the string around it.

You can end a spline either by taking it back to its original starting point or by right-clicking or double-clicking.

Splines allow you put fun and crazy curves into your shapes—and useful curves, such as those in the body of a guitar (see Figures 4-52, 4-53, and 4-54).

Figure 4-52. A combination of simple splines

Figure 4-53. With the segments closed, the splines become a shape

Figure 4-54. By applying extrusion tools and other detailing, the shape becomes three dimensional

To use the Spline tool:

1. Select the Spline tool from the Sketch toolkit (Figure 4-55).

   

   Figure 4-55. Select the Spline tool

2. Click in the main plane to create your first point (Figure 4-56).

   

   Figure 4-56. Create the first point

3. As shown in Figure 4-57, move your mouse and click again to create your second point. (This will show up as a straight segment—that’s OK.)

   

   Figure 4-57. Create the second point

4. Move your mouse and click once more. You will now see the curve (Figure 4-58).

   

   Figure 4-58. Move the mouse and click to see the curve

5. Continue clicking to make your desired shape (Figure 4-59).

   

   Figure 4-59. Another click expands the shape

   Note

   The closer together your anchor points are, the tighter the curve of the spline will be.

6. If you’re making an open shape, you can either double-click to end the sketch and then hit Escape, or click the checkbox to exit your sketch.

7. If you’re making a closed shape, you’ll see that a blue box appears when you get back to your starting point (Figure 4-60).

   

   Figure 4-60. Start the closed shape with the first click

8. When you’ve created your spline, you can still tweak it by clicking and dragging on anchor points until you’ve got your desired shape.

Like rectangles and circles, splines are most useful in conjunction with other shapes and geometry features (Figure 4-61 and Figure 4-62).

Figure 4-61. Which primitives have been combined with splines to create this shape?

Figure 4-62. Here, simple circles, cylinders, and splines add up to a complex 3D object

Two-Point Arc

The Two-Point Arc tool allows you to define a curve by setting two points and adjusting the amount of curvature between them.

1. Select the Two-Point Arc tool from the Sketch toolkit (Figure 4-63).

   

   Figure 4-63. An arc of two points

2. Click on your grid or solid surface to begin sketching.

3. Click once where you’d like the center of your arc to be (Figure 4-64).

   

   Figure 4-64. The center of the arc of two points

4. Click again or type in your radius to specify where you’d like the arc to start (Figure 4-65).

   

   Figure 4-65. The radius of the arc of two points

5. Move the mouse and click again to define the end point of your arc (Figure 4-66).

   

   Figure 4-66. The end of the arc of two points

6. And now you have a two-point arc! You can begin another arc on the plane, or click the checkmark to exit the Two-Point Arc tool (Figure 4-67).

Figure 4-67. Exiting the arc of two points

Three-Point Arc

The Three-Point Arc tool allows you to define a curve by setting three points (two end points and a middle). The software then automatically sets the amount of curvature between them.

1. Select the Three-Point Arc tool from the Sketch toolkit (Figure 4-68).

   

   Figure 4-68. An arc of three points

2. Click on the main plane, a Face, or a Solid to start sketching.

3. Click on the sketching area where you want your arc to begin (Figure 4-69).

   

   Figure 4-69. The start of the arc of three points

4. Click again where you want your arc to end (Figure 4-70).

   

   Figure 4-70. The end of the arc of three points

5. Click to select the third point (Figure 4-71).

   

   Figure 4-71. The third point of the arc of three points

6. You’ve created a three-point arc. Now you can begin a new arc, or click the checkmark to exit the three-point arc tool (Figure 4-72).

Figure 4-72. Exiting the arc of three points

Fillet: Adding a Rounded Corner

You can round the edges of an object with an operation called a fillet. In CAD lingo, this word is pronounced as it’s written, saying the t at the end (experienced CAD users can always spot a newbie when they hear this term pronounced as if it’s a piece of fish).

You can round edges while in Sketch or 3D Modeling mode. It depends on what order of operations you’re most comfortable with, and what will work best for your model.

To fillet:

1. Choose the Fillet tool from the Sketch toolkit (Figure 4-73).

   

   Figure 4-73. Choose Fillet

2. Select the sketch you want to edit, and then select one line (Figure 4-74) followed by another that you want to round (Figure 4-75). Or, select a corner that you wish to round.

   

   Figure 4-74. Pick the first of two lines to round with the Fillet tool

   

   Figure 4-75. Then pick the next line

3. You can enter a specific radius (Figure 4-76), or push and pull the arrow (Figure 4-77) to make your fillet, using the Fillet Radius box that comes up when you select the Fillet tool.

Figure 4-76. Enter a specific radius if desired

Figure 4-77. Or, push/pull the arrow to curve the edge

Trim

The Trim tool is very useful when creating complex shapes, or if you need an exact shape with a complex curve in it. It allows you to remove external material from your sketch. To use the Trim tool, follow these instructions:

1. Choose the Trim tool (Figure 4-78) from the Sketch toolkit.

   

   Figure 4-78. The Trim tool

2. Click the sketch you wish to edit (Figure 4-79). The sketch must contain some overlapping lines.

   

   Figure 4-79. Select the sketch you want to trim

3. Hover over the overlapping line or lines you want to trim, and you’ll see them turn red (Figure 4-80).

   

   Figure 4-80. The line to be trimmed turns red

4. Click on the red line to remove it (Figure 4-81).

Figure 4-81. Remove the red line with a click

Extend

Extending a sketch is a reliable way to make sure that your sketch connects to the next intersecting line.

1. Select the Extend tool (Figure 4-82) from the Sketch toolkit.

   

   Figure 4-82. The Extend tool

2. Select the sketch that you want to work with (Figure 4-83).

   

   Figure 4-83. Select the sketch that you wish to extend

3. Select the arch within the sketch that you want to extend (Figure 4-84). A red line will appear (Figure 4-85) indicating where your sketch will extend to.

   

   Figure 4-84. Select the arch that you wish to extend

   

   Figure 4-85. The red line shows how far the sketch will extend

4. Click the checkbox or hit the Enter key and the shape will become solid (Figure 4-86).

Figure 4-86. An extended sketch.

Offset

Offsetting lets you create thicker walls on objects with more complex shapes. In some situations, you can also do this with the Shell tool.

To use the Offset tool:

1. Select the Offset tool from the Sketch toolkit (Figure 4-87).

   

   Figure 4-87. The Offset tool

2. Select the sketch that you want to offset (Figure 4-88).

   

   Figure 4-88. Select the sketch to be offset

3. Hover your mouse over a line on that sketch.

4. Enter your measurement (estimate if you’re not sure), and then select the green check button or press the Enter key, and your offset will be finished (Figure 4-89).

   

   Figure 4-89. An ellipse with an offset

Extrude

Use the Extrude feature when you want to model a cube or shape that starts with two flat sides.

Figure 4-90 and Figure 4-91 show just a few examples of what you can do with the Extrude tool, which you’ll find yourself using almost as much as the sketching tools.

Extrusion means to take a 2D sketch and add that third dimension that turns it into an object. Shapes can be extruded up, down, or outward, according to the measurements you desire.

Figure 4-90. A flat, 2D image

Figure 4-91. The flat image, extruded into the third dimension

One particularly useful aspect of the Extrude tool is that it allows you to create models from premade parts. You can make a premade part more complex by sketching on an already-extruded surface and then extruding what you’ve sketched. In this way, you can add new surfaces to the object.

You can also extrude in the opposite direction to create pockets or holes. This process is called cutting, because it cuts away surface area from the solid shape.

Here are the basics of using the Extrude tool:

1. Start with a sketch (Figure 4-92).

   

   Figure 4-92. Start the extrusion process

2. Select the Extrude tool, shown in Figure 4-93, from the Construct toolkit.

   

   Figure 4-93. The Extrude tool

3. Select the sketch, or you can select the Extrude tool from the gear symbol that appears once you’ve selected the sketch.

4. When you select the sketch, a little white arrow will appear, along with a dialog box. As with other tools, you can either type in specific measurements or click and drag the arrow until you have the size you want. When you’re satisfied, hit the Enter key (Figure 4-94).

While you’re still in the Extrude tool, you’ll see a circle on an arc. You can click the circle and drag it to create a draft angle, altering the width of the top of the part. This comes in handy when making injection-molded parts. If you’re planning to mass-produce a plastic injection-molded object, you’ll want to use a draft angle of 2%.

Figure 4-94. The selected sketch

If you want to create holes or pockets in your object, begin with a sketch on a flat surface. Select the Sketch tool and then select Flat Surface. Once you’re done sketching, select the Extrude tool and pull it back through the part (Figure 4-95). You’ll see the extrusion previewed in red, and you’ll also see the little icon in the drop-down menu change from the join icon to the cut icon.

Figure 4-95. The extruded sketch

Sweep

Use Sweep when you want to make something like a piece of tubing or bent pipe.

Sweep is an efficient way to build more complex designs that involve tubing, such as a bicycle frame. To create a sweep, you need:

• A profile or shape for the tube (this is the shape that you would see if you looked at the tube from an open end)

• A path for the profile to follow

These are shown in Figure 4-96.

Figure 4-96. The two sketches you will need to create for this tool on flat grid

You’ll need to move your sketch so that it’s perpendicular to the sketch of your path. To do this, first select the profile sketch. In the pop-up gear menu, select Move, and use the orbit controls to toggle your sketch into place (Figure 4-97).

Figure 4-97. Use the move tool to make your flat profile sketch perpendicular to your path using the Move tool

Now, select the Sweep tool, shown in Figure 4-98, from the Construct menu.

Figure 4-98. The Sweep tool

A dialog box will appear, asking you to select a profile to sweep and then select a path to sweep that profile down (Figure 4-99).

Figure 4-99. The profile sketch perpendicular to your path sketch

Figure 4-100 shows the result. You’ll find Sweep very helpful when working on projects that have cords or bent tubing.

Figure 4-100. Finished preview of the Sweep tool

Revolve

Use Revolve when you want to make a part like a bowl, a cup, or a chess piece.

To use the Revolve tool, your sketch must contain a shape you want to revolve and an axis that you want it to revolve around. With simple objects like bottle or cup shapes, you can create a vertical line that will become the axis your sketch will rotate on.

This chess piece is an example of a shape that involves a closed revolve. To make it, create an outline of one-half of the final piece. Remember that in 123D Design you can have overlapping shapes and you can select multiple sketches for the same feature.

Once you’ve made your sketch, select the Revolve tool, shown in Figure 4-101, from the Construct toolkit.

Figure 4-101. The Revolve tool

When you select the Revolve feature, a little dialog box will appear. It’s always a good idea to have a look at these dialog boxes to see what they’re asking for. In this case, it’s asking you to choose the profile you’d like to rotate (Figure 4-102).

Figure 4-102. Choose the profile to rotate

You’ll see your selected profile highlighted in blue. Next, select the Axis button in the pop-up menu dialog box (Figure 4-103). This is how you choose the line that will be the axis.

In the dialog box, type the amount that you’d like to rotate the profile. In most cases (this one included), you’ll want to rotate through 360 degrees.

Figure 4-103. Select the Axis button to rotate the profile on its axis

Figure 4-104 shows the final result after revolving a profile on an attached axis. The holes were added after the revolve.

Figure 4-104. When the profile of a shape is revolved around a central axis, the result is a 3D object

You can also revolve a shape around an axis that isn’t attached to the profile. For example, see Figure 4-105 and Figure 4-106.

Figure 4-105. Note that the axis is detached and is several units to the left of the profile

Figure 4-106. Revolving a profile around a detached axis creates an opening in the final shape

Loft

Use Loft when you want to create a complex shape based on multiple profiles or sections.

Lofting is the favored choice for product designers, especially those looking to make ergonomic shapes. For example, let’s say you need a handle for an ice axe, which is a rather complex shape (Figure 4-107).

Figure 4-107. How to make a complex shape by combining profiles

This operation is called lofting because you literally loft one sketch up to another. It may sound complex, but it’s really quite simple. You start with a profile for the beginning of the loft, and then choose a second profile that will guide the first profile to the place you want it to go. Lofting is also a chance to use some projected geometry.

To get started, you’ll need to create a series of sketches based roughly on an original. I suggest starting with a basic shape by copying and pasting it to set up your planes. You can do this by using Ctrl-C and Ctrl-V on any closed sketch (Figure 4-108).

Figure 4-108. Start with a circle

Be sure that your closed sketch doesn’t have overlapping lines. When a loft doesn’t work, it’s usually because the sketch has lines that are overlapping or aren’t connected (and therefore the sketch isn’t closed).

Let’s try it:

Sketch a circle. Then copy and paste your circle a few times. With each paste, drag the circle vertically to somewhere else in the sketching space (Figure 4-109).

Figure 4-109. Copy and paste several sketches of a circle vertically in the main plane

For this particular example, I offset each circle with an ellipse, giving the shape the characteristics of a hand grip (Figure 4-110).

Figure 4-110. Sketches of circles alternating with ellipses

In this scenario, as in most lofting scenarios, you’re going to loft more than one sketch to another. To do this, hold down the Shift key and select each sketch, in order. In other words, start at one end and work your way toward the other (Figure 4-111).

Figure 4-111. Hold down the Shift key and select each sketch in order, either from top to bottom or bottom to top

With all the shapes selected, click on the Loft tool from the pop-up menu or the Construct toolbar (Figure 4-112).

Figure 4-112. Click on the Loft tool after all the shapes are selected

Now you can see the result: almost like magic, the sketches are connected into a whole. If you are not happy with the result, simply undo or Ctrl-Z each step, change your sketches, and then repeat the Loft command.

Here is the final result of lofting my stack of circles and ellipses, before (Figure 4-113) and after (Figure 4-114) I added some texture.

Figure 4-113. The lofted stack of circles and ellipses

Figure 4-114. With the addition of texture, the lofted object begins to resemble a handgrip

Fillet

As with the sketch fillet tool earlier, fillets should always be added last, as they can turn a boring straightforward design into an organic masterpiece.

To use a fillet, simply select any edge. Edges are marked with black lines tracing the object. After selecting the edge, hover over the pop-up menu and select the fillet command. Than drag the arrow in or out or enter in a measurement (Figure 4-115).

Figure 4-115. Select an edge… and fillet it!

Try it now by building a simple box and filleting the edges.