Monday, 8 August 2011

Evolve to 3D

For All Solid Edge users, there is a four-step process that is available to them that allows them to evolve to 3D at a comfortable pace. The goal is to make the move to a full 3D design process on a case-by-case basis.

Figure 1. Here's an example that shows the visualization and communication advantages of working in 3D.

Step one > Protect Your Legacy Data

Now, let's use the AutoCAD Translation Wizard for this example as we go through the import tasks. You can start by mapping AutoCAD line types to Solid Edge line types by clicking on the Solid Edge line type, and then selecting a line type from the drop-down list. You can continue this process in a similar fashion to import AutoCAD element colors to Solid Edge line widths, as shown in Figure 2; AutoCAD fonts to Solid Edge fonts; and AutoCAD hatch styles to Solid Edge hatch styles. Finally, you can define a configuration file to save these mappings for future use. To do this, click the Create a New Configuration File option, and then click the Copy To button. On the Save As dialog box, define a folder and document name for the new configuration file.

Figure 2. Remapping an AutoCAD element color using the translation Wizard is as simple as clicking a color, and then selecting a width from the drop-down list.
Step two > Turn 2D into 3D
Create a 3D command allows you to quickly turn your 2D drawings into intelligent 3D models for use in assemblies or downstream operations. For example, the Create 3D command displays a dialog box, as shown in Figure 3, which prompts you for the drawing view elements you want to include in a sketch and to specify the preferred projection angle to use when the sketches are created in the new document. After you specify the projection angle, select the view type of the elements you want to include in the sketch. You can choose folded principal views, folded auxiliary views, or copy views. Folded principal views are orthogonal or aligned with the primary view. You can select this view type to define the primary view. Folded auxiliary views are true auxiliary views that are generally derived from principal views and require a fold line to determine the edge or axis around which you want to fold the view. Copy views are not orthogonal and may not actually align with the primary view. These views are placed as sketches on the same plane as the last principal view defined in the draft file.
After you define this information, you can select the geometry needed to create the sketches. You can include lines, arcs, circles, curves, polylines, and line strings created with imported data. You can also select which drawing views should be used to define the 3D model with full control over creation of the model using standard Solid Edge features, as shown in Figure 3.
Step three > The Hybrid 2D/3D Design Workflow
Reuse of 2D data need not be limited to individual parts. First, create assembly layouts (as well as parts) for new designs, using familiar 2D concepts. Next, add 3D as you progress, mixing and matching 2D and 3D representations of parts, and only adding 3D detail when required. This provides you with a true hybrid 2D/3D workflow that gives you control of the process, allowing you to fit it to your company's needs.
Step four > Full 3D Design
When you are ready, make use of the workflows you have learned and the data you created to move to 3D. Solid Edge's user interface guides you through standard workflows to create parts and assemblies. Design functions are automated, from concept layout through detail design and drafting. They also include built-in data management and integrated applications for analysis and manufacturing.

Figure 3. The Create 3D command lets you turn 2D drawings into intelligent 3D models for use in assemblies or downstream operations.

Users can use this step-by-step system to move to 3D at a comfortable pace. They can also choose to use the hybrid 2D/3D design capabilities of Solid Edge before moving to full 3D for as long as necessary.
Happy enjoy it!

Engineering Reference

Most engineers either design based on experience and then test their designs with prototypes, or they use engineering calculations and formulas to predict design suitability. Regardless of approach, the Engineering Reference feature in Solid Edge provides access to powerful calculation-driven design tools that reduce the need for costly physical prototypes. As a result, moving engineering costs to a much earlier phase in the product lifecycle reduces production costs.

Calculation- and Formula-Driven Design
Engineering Reference is a calculation- and formula-driven design tool for engineers and designers of machinery with design components such as shafts, cams, gears and springs (figure 1). Engineering Reference embeds engineering reference information within Solid Edge to help engineers design by function as well as form. Fully integrated with Solid Edge, it is designed to preserve the engineer's design intent. This feature allows Solid Edge users to employ engineering calculations to automatically create mechanically correct parts and reuse knowledge-based engineering principles.

Figure 1. Engineering Reference tool.
Automatic Component Modeling
Systems design places additional emphasis on the function of a product and how its components interact with each other, which enhances productivity by reusing knowledge already captured during the design process or within existing engineering design principles. Engineering Reference is accessible through a new tab on the EdgeBar. The tool uses mechanical engineering rules that encapsulate machine design theory to generate parametric 3D parts. It automatically creates Solid Edge part models based on engineering formulas and application service conditions of the components.
If a design change is required, users edit the part by returning to the Engineering Reference where the operating conditions and parameters are changed and the model automatically updates. Knowledge captured in the component design is then used to quickly update the model.
Common Parts in Machine Design
You can simply choose the component type from the EdgeBar and enter the relevant design parameters in dialog box. Engineering Reference supports industry standards including ANSI, DIN and JIS, and it helps engineers design, select and strength-check a broad range of common machinery components, including
  • Cams
  • Shafts
  • Spur gears
  • Bevel gears
  • Extension springs
  • Compression springs
In this exercise you will become familiar with Engineering Reference interface. Any values used are purely to help you become acquainted with carrying out a design calculation.

1. Start a new part or assembly. Choose the last tab from the Solid Edge EdgeBar -- Engineering Reference. You will see the different types of components that Engineering Reference can help you design (figure 2). For this exercise, double-click on Shafts to design a new shaft.

Figure 2. Available part types.
2. The Shaft Designer dialog box opens, and you input your desired parameters or sizes (figure 3).

Figure 3. The Shaft Designer dialog box.
3. Next, click on the Materials button. Choose steel, or any other material, from the drop-down menu (figure 4).

Figure 4. Available materials values.
4. Make some changes to some of the parameters. Change the (d) diameter to 25 and (L) length to 35. Leave the support number at 2 and the Element (the number of steps in the shaft) at 6. Now add a 10 mN force to the XZ Plane (figure 5).

Figure 5. Change the parameters.
5. Choose the Calculate button to view the results. At this point, you can check the figures to see if your part is strong enough for its intended use (figure 6).

Figure 6. View the calculate results.
6. Now simply click on the Create button on the bottom edge. Solid Edge will automatically create the shaft for you (figure 7).

Figure 7. The finished shaft part.
7. After the shaft is placed in an assembly file, you can edit it with the Engineering Reference tools used to create the part. Select your part from pathfinder, click the right mouse button to select the shortcut menu and select Edit in Solid Edge Shaft Designer (figure 8).

Figure 8. The Edit in Solid Edge Shaft Designer command.
Look at some of the other parts that you can design with Engineering Reference. They all work in a similar manner; simply substitute the default values for your own. Don't forget to add a load, calculate to check your results and then create your parts. Engineering Reference is intuitive and will save you time when designing and creating your components.
See you next..!

Using Solid Edge's Drawing Review Mode

If you work on large assemblies, chances are that you will create drawings of those assemblies. Solid Edge provides some neat tools that help you compose drawings of large assemblies quickly. After your initial drawings are created, most people only need to access drawings to review, print, measure, and add annotations to them. Since Version 20, Solid Edge's drawing review mode allows you to almost instantly open 2D drawings of massive assemblies, drastically decreasing the time it takes to access your drawings from minutes to seconds and saves system resources..
Solid Edge's Drawing Review mode.
Drawing Review Mode
Drawing review mode lets you rapidly open a drawing regardless of how big or detailed the drawing is. In this inactive drawing review mode, dimensions and annotations can be quickly applied to orthographic drawing views, you can even extract balloons to call out part numbers. As you can see Drawing Review mode is quite versatile, however there are times when you need access to the underlying 3D model geometry (for example, to establish a true dimension in an isometric view). In this case, you can easily activate drawing views on the fly and continue to work as you would as if the drawing had been opened normally. Geometry is loaded into memory so you can derive true dimension sizes. To reclaim some resources you can just as easily 'inactivate' the view once you are finished working on it.
Whether you are part of a design review team, a shop floor worker who needs to quickly print a drawing, or a detailer who needs to annotate drawings as quickly as possible, you'll like Drawing Review mode and the time it saves you.
How to Use Component Grouping
Using Drawing Review mode is as easy as opening up a drawing file. On the Open File dialog box, use the right-mouse button options and drag-and-drop to choose the Inactive Drawing View for Review option and click on the Open button. Your drawing should open very quickly.

Solid Edge Drawing Review menu showing active and inactive options.
Notice that the drawing is watermarked onscreen as inactive (it doesn't print). You can now print, review, and add annotations to your drawing.

Drawing view with the inactive watermark.

Active and inactive drawing view switch under the Applications menu.
If you need to add true dimensions to isometric or pictorial views or you want to extract a bill of materials, simply select Activate Drawing Views under the Applications menu. You can just as easily inactivate them after you've finished. That's all there is to it. Drawing Review mode will prove a welcome addition to the massive assembly capabilities delivered with Solid Edge and will provide the ability to open drawings in record time.
See you next time On the Edge.

Solid Edge Design Sensors

Design Sensors are part of Solid Edge's Systems Design capabilities that also include Variable Limits, Motion, Systems Libraries, Fastener Systems, Adjustable Assemblies, Capture Fit, and more. In this article, I'll discuss how to create and use Design Sensors to ensure critical design dimensions are maintained throughout your design cycle. As the name implies, Design Sensors constantly monitor critical dimensions. They are dynamic, so if a monitored value is found to be out of range,
A Minimum Distance sensor is one example of how Design Sensors monitor design dimensions.
you are notified instantly. Sensors are easy to create and have almost no impact on system performance. Design Sensors are available in Part, SheetMetal, and Solid Edge Assembly environments. They are used to monitor many design situations, for example minimum distance -- if a hole gets too near the edge of a component, you are notified.
The Variable sensor monitors variables from your variable table. Sheet Metal sensors offer specifics such as monitoring internal faces that warn bends are too close together to be manufactured. A Surface Area sensor is helpful if you need to know how much surface finish is required or the minimum surface area for heat. If you need something outside the box, you can use a custom sensor to monitor any numeric result that is calculated from a custom program. For example, you could create a custom program that assigns a manufacturing cost to each feature type used for creating sheet metal parts.
When a monitored condition is out of range, sensor alarms and violations are highlighted in the sensors tab in Edgebar and graphically in the upper right corner of the graphic window. Clicking this graphic launches the Sensor Assistant, which provides hyperlinks to all the sensor violations and warnings in the document.

Click the Design Sensor alarm to launch the Sensor Assistant.
How to Set Up and Use Design Sensors
Design Sensors are quick and easy to set up; you should use them in any situation in which critical dimensions must be within range. In this exercise, I'll create a Design Sensor to watch a minimum distance between the edge of a hole and the edge of a plate it is placed through. Other types of sensors work in a similar fashion, so once you know the workflow in this exercise, you will be able apply other types of sensors.
Start by creating a plate 150 mm square, and place a 15 mm hole in the corner that is located 30 mm from each edge.

Create the base geometry.
Select the Sensors tab from Edgebar.

Select the Minimum Distance Sensor.

From the selection options pick Keypoints/Curves/Faces.

Select the front face, and use QuickPick to select the face of the hole. You should see a display showing the vector you are monitoring and the actual sensor parameters. Then select Close from the SmartStep Ribbon Bar.

Give your sensor a name (1) and fill in and choose the values outlined in red from the Sensor Parameters dialog (2-6). Items outlined in green provide live feedback. Select OK

Your sensor will display in Edge bar. You can create as many sensors as you like.

Now edit the hole position by using QuickPick to select the hole.

Now edit the dimension adjacent to the sensor and reduce it from 30 mm to 15 mm. Notice the sensor now has a warning next to it.

Also notice there is an exclamation mark in the upper right corner of graphics window. If you click on this, it will launch the Sensor Assistant. Sensor Alarms indicate when a change to the model exceeds the defined sensor threshold limit.
The Sensor Assistant keeps track of sensor alarms that have been triggered by changes to the model. It quickly accesses the affected sensor definition information so you can review it and fix the alarm or the model as needed.
You can activate or deactivate the Sensor Assistant and alarm notification in the graphic window using the Show Sensor Indicator option on the Helpers tab of the Tools / Options dialog box. This does not affect the operation of the sensors themselves.
For more detailed information on sensors, the Solid Edge Help menu has more advice on how they work, the kinds of sensors available, and even some great examples. If you're not already using sensors, try them out. They will help you reduce costly design errors and costly prototypes.

See you on the Edge next time.

Manipulate the Synchronous Technology Steering Wheel

Solid Edge with Synchronous Technology can remove the barriers of traditional history-based modeling more predictably than explicit modelers. The Steering Wheel is an integral component of Synchronous Technology, enabling users to directly manipulate 3D model geometry. It's intuitive and easy to use, but there are some powerful options under the skin that you can exploit. Following these techniques will shorten your learning curve and ease your adoption of Synchronous Technology.

Let's start with the anatomy of the Steering Wheel.
 Key components of the Solid Edge Steering Wheel.

  • The origin is used to reposition the Steering Wheel.
  • The major or minor axes and the disc-shaped plane in the center initiate the Move command.
  • The torus is used to rotate geometry.
  • The bearing is used to adjust the orientation of the tool.
  • The plane is used to keep the steering wheel or geometry "on plane" while moving.
Moving faces, the steering wheel is activated by selecting a face or faces to edit. Click on the major axis to easily pull the faces in that direction, without concern for the order in which features were created.
(Top Tip: If you hold Shift and click on the origin before dragging the Steering Wheel, its orientation is preserved while it is moved.)

Move faces with synchronous technology using the Steering Wheel axis.

To rotate a face, select the face to be rotated, then reposition the Steering Wheel by dragging the origin so the torus is perpendicular. The steering wheel snaps to key points and re-orients automatically. Click on the torus to rotate the face. (Top Tip: If you hold Shift and click on the plane it swaps the axis of the Steering Wheel — very handy if it does not orient automatically. Using the Tab key moves focus to the dimension box, allowing you to type in a precise angle if you wish.)
Rotate faces with synchronous technology using the Steering Wheel torus.

Another modifier key can also be used while manipulating geometry. Hold down the Ctrl key while dragging the axis to copy your selected geometry or feature; using key points, you can accurately position the geometry.

Copy geometry with synchronous technology by using the Steering Wheel axis and holding down the Ctrl key.

To move geometry to a precise distance from other geometry or reference point, first index the Steering Wheel your chosen distance from the face being moved.
  • To do this, hold Shift and click on the primary axis, then press the Tab key to switch the focus to the dimension box, type in 6mm (the distance you want the feature to be offset), and click to accept (see Step 1).
  • Now select the primary axis and drag it to the reference key point on adjacent geometry (see Step 2).
  • I've placed a 3D dimension so you can see the new distance is 6mm (see Step 3).

1. Index Steering Wheel a precise distance from face to be moved. 2. Snap to key point of reference geometry. 3. The result: The face of the boss is precisely 6mm from adjacent geometry.

Nice..let's try it now!

Quickly Rename Parts and Features

Being forced to exit your CAD system and use Windows Explorer to rename parts can spoil your workflow. In this column, I'll show you how Solid Edge allows you to rename parts, assemblies, and features directly from the user interface.

Select the desired part and press F2 to invoke the Rename feature. Type in a new name and press the Enter key to accept the change.

Changing the name of a part feature is just as easy: Select the feature to rename, then press F2 to start the Rename mode. Type a new name and press Enter to keep the new description.

There's more — you can change the name back if you need to. Select the feature again, press F2, delete any text completely, press Enter, and the original name will be restored!

Happy enjoy it!

ISO Paper Sizes


There has alwas been some confusion over the size of standard ISO drawing sheets with AutoCAD.The stated sizes in the plot dialogue box are not the true ISO sizes, rather they relate to the plotted area on standard size cut sheets. Obviously it is not possible to print right to the edge of cut sheets, so the AutoCAD sizes quoted are always smaller than the true cut sheet size. See the "Paper Size" dialogue box on the right.
Relationship of paper sizesTo some extent this issue has been physically resolved by the use of roll feed plotters. For example, a true A3 print can be made from an A1 roll. Despite this fact, AutoCAD still quotes the plotted area sizes in the plot dialogue box. If you look at the dialogue box above, you will see that it is possible to enter your own "USER" paper sizes which can be set as true ISO sizes. In this example the "USER" size has been set to A3. Use the sizes in the table below, which are the true ISO cut sheet sizes as a guide.
Paper sizes in millimetres
A0 1189 x 841
A1 841 x 594
A2 594 x 420
A3 420 x 297
A4 297 x 210
A5 210 x 148
The ISO paper sizes are devised in such a way that each smaller size is exactly half the size of the previous one. For example, cutting an A3 sheet in half so that the cut is perpendicular to the longest side would result in two A4 sheets. See the illustration above.

Drawing ISO Sheets in AutoCAD

The simplest way to draw drawing sheet outlines is to use the Rectangle command, picking the lower left hand point and then entering a relative co-ordinate for the upper right.

For example

To draw an A3 sheet:
  1. Start the Rectangle command, type RECTANG at the command prompt, pick "Rectangle" from the "Draw" pull-down or click on the Rectangle button.
  2. At the Chamfer/Elevation/Fillet/Thickness/Width/<First corner>: prompt, pick a point somewhere in the lower left of the drawing area.
  3. At the Other corner: prompt, enter a relative co-ordinate using the appropriate drawing sheet dimensions, type @420,297 and right click orReturnat the keyboard.
  4. Your drawing sheet outline will now be drawn at the correct size. If you cannot see all of the rectangle, use Zoom Extents to view the whole thing. You can do this by typing Z Return E Return at the keyboard (Z is the keyboard shortcut for the Zoom command).

Drawing Scaled ISO Sheets

The drawing sheet sizes in the table above can easily be used to draw sheet outlines in Paper Space since plotting from Paper Space should always normally be at a scale of 1=1 and Paper Space drawing units should be equivalent to millimetres. However, drawing sheet outlines in Model Space is rather more complicated because you need to take into account both the intended plot scale and the drawing units (which may not be millimetres). Fortunately there is a straightforward formula which you can use to determine the actual size of your required sheet outline in drawing units.
Drawing Units per metre x Scale x Sheet Size in metres

For example

An A3 sheet at 1:200 and drawing units in millimeters can be calulated as follows:
1000 x 200 x 0.420 = 84000
1000 x 200 x 0.297 = 59400
An A3 sheet at 1:500 and drawing units in metres can be calculated as follows:
1 x 500 x 0.420 = 210.0
1 x 500 x 0.297 = 148.5

Plotting from Model Space

Plot scaleThe only other consideration you need to make when plotting in Model Space is the plotting scale. This will be different depending upon which drawing units you are using.Working in millimetres is straightforward because you can use the actual scale in the Plot dialogue box since plotted units are also in millimetres. For example, a drawing to be plotted at 1:500 with drawing units in millimetres will have a plot scale of 1=500. Working in metres is a little more complicated. You will need to divide the scale by 1000 to get the correct figure. For example, a drawing to be plotted at 1:500 with drawing units in metres will have a plot scale of 1=0.5 which is 1000 times smaller than the figure for millimetres because there are 1000 millimetres in a metre.
Common Plot Scales
Plot Scale Plotted MM   Drawing Units
1:20 1 = 0.02
1:50 1 = 0.05
1:200 1 = 0.2
1:500 1 = 0.5
1:1250 1 = 1.25
1:2500 1 = 2.5
The table above lists a number of common plot scales and their corresponding plot scale factors which should be used when plotting from Model Space and when drawing units are in metres.

that's all. i hope this can be usefull for you ;)



This tutorial describes the options and commands available for dimensioning drawings and how to use them. The correct use of AutoCADs dimension tools is the key to producing clear and concise measured drawings. If you just need to quickly find a description of the various dimension commands, click on the appropriate button on the QuickFind toolbar below.
Linear DimensionAlighed DimensionOrdinate Dimension Radius DimensionDiameter DimensionAngular Dimension Baseline DimensionContinue Dimension LeaderTolerance (not covered in this tutorial)Center Mark Dimension EditDimension Text Edit Dimension Style Dimension Update
AutoCAD provides a whole range of dimensioning tools which can be used to quickly dimension any drawing without the need for measurement. Dimensioning in AutoCAD is automatic; lines, arrows and text are all taken care of by the dimension commands. AutoCAD dimensions are special blocks which can easily be edited or erased as necessary.
AutoCAD provides lots of control over the way dimensions look. Using a system similar to text styles, dimension styles allow you to design dimensions so that they look just the way you want them to.
For example, the illustration above shows two different dimension styles. The one on the left is the default style known as STANDARD. If you do not create a style of your own or modify the standard style, all dimensions will look like this. The dimension line has arrow heads and the dimension text is positioned above the line and is drawn using the current text style. The dimension on the right has been drawn using a new style. The arrows have been changed to obliques, the vertical alignment of the text has been centred and the current text style has been changed.
There are lots of dimension commands which include facilities for indicating tolerances and alternate units dimensioning. However, this tutorial aims to cover the most common commands for general use and constitutes an introduction to dimensioning with AutoCAD. If you would like to learn more about dimensions, refer to the AutoCAD user manual.
AutoCAD divides dimensions into four main categories: Linear, Radial, Ordinate and Angular. For the purposes of this tutorial we will only consider some of the commands within the Linear, Radial and Angular categories.
When you create dimensions, AutoCAD automatically creates a new layer called "Defpoints". This is a special layer which cannot be deleted or renamed. AutoCAD uses this layer to store dimension information and you can effectively ignore it.
When working with dimensions it is very important that line origins are picked accurately so that the resulting measurement and text are correct. Always use an Osnap to pick dimension line origins. If you have a lot of dimensioning work to do, it will be worth using a running Osnap. Running object snaps are set using the Osnap Settings dialogue box. To display this dialogue box type DDOSNAP at the keyboard or select ToolsObject Snap Settings from the Pull-down menu. There is also a keyboard short-cut; you can display the Osnap Settings dialogue box simply by hitting the F3 key.
This tutorial is not designed as a reference for dimensioning conventions. If you wish to learn more about dimensioning conventions, consult BS 308: Part 2.

Selecting Dimension Commands

Selecting and working with the dimension commands in AutoCAD R14 is much easier than in previous versions. All commands can be accessed from the keyboard and now most commands are also available from the Dimension pull-down menu and the Dimension toolbar. The Dimension toolbar is particularly useful because it places all the dimension commands a single mouse click away. Since the Dimension toolbar is not displayed by default you will need to enable it from the Toolbars dialogue box. To display the Toolbar dialogue box, select ViewToolbars… from the pull-down or type TOOLBAR at the keyboard. To display the Dimension toolbar, click in the checkbox against "Dimension" in the toolbar list.

The Linear Dimension Commands

As the name suggests the Linear dimension commands are used to dimension along straight lines. There are five linear dimension commands, namely: DIMLINEAR, DIMCONTINUE, DIMBASELINE, DIMALIGNED and DIMROTATED. The DIMLINEAR command is probably the most common dimension command you will use.

The Linear Dimension Command

Toolbar Linear Dimension
Pull-down DimensionLinear
You can use this command to generate horizontal and vertical dimensions.
Creating a linear dimension is easy. All you have to do is start the command, specify the two points between which you want the dimension to be drawn and pick a point to fix the position of the dimension line. Consider the diagram (right) whilst working through the following examples.

Command Sequence

First extension line origin or press ENTER to select: (pick P1)
Second extension line origin: (pick P2)
Dimension line location (Mtext/Text/Angle/Horizontal/Vertical/Rotated): (pick a point to position the dimension line, you will see the dimension rubber banding)
You may have noticed that the first prompt asks you to pick the first extension line origin or to press the ENTER key. Pressing the Enter/Return key results in the following prompt:
Select object to dimension: AutoCAD allows you to dimension an object simply by picking it. Try this out. Draw a line or a circle and use this option rather than the two point option to see what happens.
Dimensions will automatically adjust themselves to accommodate most situations. For example, the illustration on the right shows what happens to a dimension if the gap between the two extension lines is too small for the dimension text.

The Continue Dimension Command

Toolbar Continue Dimension
Pull-down DimensionContinue
You can use the Continue command to add a string of dimensions. In the illustration above the "36mm" dimension has been continued from the "64mm" dimension.

Command Sequence

Specify a second extension line origin or (Undo/<Select>): (pick P3)
Specify a second extension line origin or (Undo/<Select>): (pick another or Return to end)
Note: There is no prompt for the first line origin, AutoCAD automatically selects the second line origin of the previous dimension to be the first of the new dimension. There is also no prompt for the dimension line position, AutoCAD automatically matches up with the previous dimension.
Using the Continue command you can very quickly generate a string of dimensions which align perfectly. In the example above, the "34.41" dimension was drawn with the DIMLINEAR command; all the other dimensions were drawn using the DIMCONTINUE command and simply picking the four points, one after the other. You can only continue a dimension in a single direction. To generate the "26mm" dimension in the previous illustration, you will need to use the DIMLINEAR command and pick P3 and P4 or enter Return at the first prompt and pick the line.

The Baseline Dimension Command

Toolbar Aligned Dimension
Pull-down DimensionBaseline
You can use this command to generate a series of dimensions from a single base point. You must already have created the first dimension in the sequence using a command such as DIMLINEAR. The DIMBASELINE command then creates further dimensions in a similar way to the DIMCONTINUE command. All the user has to do is pick points.

Command Sequence

Specify a second extension line origin or (Undo/<Select>): (pick next point)
Specify a second extension line origin or (Undo/<Select>): (pick another or Return to end)
Select base dimension: (Return again to end)
In the example above, the "35.07" dimension was created using the DIMLINEAR command. The others were created using DIMBASELINE and picking points 1 and 2.

The Aligned Dimension Command

Toolbar Aligned Dimension
Pull-down DimensionAligned
You can use this command to generate aligned dimensions. These are dimensions along inclined lines which cannot be dimensioned with the DIMLINEAR dimension command because that command will only give a measured dimension in either a horizontal or vertical direction. However, as you can see from the command sequence below, this command works in exactly the same way.

Command Sequence

First extension line origin or press ENTER to select:(pick P1)
Second extension line origin: (pick P2)
Dimension line location (Mtext/Text/Angle): (pick a point)
The DIMCONTINUE and DIMBASELINE commands can both be used in conjunction with DIMALIGNED dimensions.

Changing the Text

You may have noticed that when you are prompted to pick the dimension line location you are also offered a number of options. The options vary depending upon the particular command that you are using. However, the Mtext and Text options, which are common to all dimension commands are particularly useful. Essentially they do the same thing, they allow you to change the text which will appear on the dimension line. The Text option allows you to enter a single line of text and the Mtext option starts the MTEXT command and enables you to add formatted, multiline text to the dimension. These options can be used to add descriptions to your dimensions or to modify the measured distance.
In the example above, the Mtext option has been used to create a multi-line annotation. When you use this option you will notice that the Multiline Text Editor dialogue already has some text in the text window. This is the measured dimension and is displayed as "<>". If you delete this marker the dimension measurement will not appear in the annotation.
Extract from the Multiline Text EditorIf you need to edit dimension text after the dimension is drawn, you can use the DDEDIT command, Modify/Object/Text… from the pull-down. If you select a dimension, the Multiline Text Editor will appear and you can make any necessary changes to the annotation. The illustration on the right shows an extract from the Multiline Text Editor as it would appear if the dimension above were selected.

The Radial Dimension Commands

There are two main radial dimension commands, DIMDIAMETER and DIMRADIUS. Both commands result in a similar looking dimension so AutoCAD automatically inserts a "R" to indicate a radius and the dimension symbol to indicate a dimension. You can get AutoCAD to display the dimension symbol by including "%%c" in any text string. For example, in order to draw the 40mm diameter text as it is shown in the illustration on the right, you would need to type "%%c40mm". You can use this special character with any of the text commands.
The Diameter and Radius commands are supplemented by the DIMCENTER command which can be used to add a center mark to any circle or arc. The DIMDIAMETER and DIMRADIUS commands do not automatically draw a center mark.
By convention it is usual to dimension full circles using a diameter and arcs (partial circles) using radius. You will find more information on dimensioning conventions in BS 308: Part 2.

The Diameter Dimension Command

Toolbar Diameter Dimension
Pull-down DimensionDiameter
You can use the Diameter command to annotate a circle or an arc with a diameter dimension. To achieve this simply start the command, pick a point on the circumference of the circle, pick a second point to determine the length of the leader and then add the dimension text or Return to accept the default.

Command Sequence

Select arc or circle: (pick the circumference P1)
Dimension line location (Mtext/Text/Angle): (move the cursor until you are happy with the text position and then pick to complete the sequence)

The Radius Dimension Command

Toolbar Radius Dimension
Pull-down DimensionRadius
The Radius command is identical to the Diameter command except that the dimension measurement is a radius rather than a dimension and the resulting dimension text is prefixed with a "R" to indicate radius.

Command Sequence

Select arc or circle: (pick the circumference P2)
Dimension line location (Mtext/Text/Angle): (move the cursor until you are happy with the text position and then pick to complete the sequence)
Notice that in the illustration above the radius dimension has been positioned inside the circle. Both diameter and radius dimensions can be positioned either inside or outside an arc or circle.
Practice with the Radial and Diameter commands until you understand how they work.

The Center Mark Command

Center Mark
Toolbar Center Mark
Pull-down DimensionCenter Mark
You can use the Center Mark command to annotate a circle or an arc with a cross at the center. The illustration above shows a center mark added to a circle after a diameter has been drawn.

Command Sequence

Select arc or circle: (Pick the circumference of a circle or arc)
A cross is drawn at the center point.

Angular Dimensions

There is only one command in this section and it is used to annotate angular measurements.

The Angular Dimension Command

Toolbar Radius Dimension
Pull-down DimensionAngular
The Angular command is amazingly flexible and can be used to indicate an angle in almost any situation. Just like the other dimension commands, all parts of the process are rubber banded so you can see the results of your actions before you make the final pick.

Command Sequence

Select arc, circle, line, or press ENTER: (pick a line)
Second line: (pick another line)
Dimension arc line location (Mtext/Text/Angle): (pick point)
Move the cursor position until you are happy with the result. Notice that you can move the cursor to either side of the lines and the angular dimension will change accordingly.
AngularYou may have noticed that at the first prompt you are given the option to press ENTER. If you use this option you will be prompted to pick the angle vertex and then the two angle endpoints. This is quite useful if the angle you need to dimension is not defined by physical lines on the drawing. The illustration on the right shows the result of this option. The centre point of circle 1 was picked as the angle vertex and the centre points of circles 2 and 3 were picked for the two angle endpoints.
The degree character is automatically inserted for you, however, if you ever need to type it, you can do so by typing "%%d". This is another of AutoCADs special characters.

Ordinate Dimensions

Ordinate dimensions are not really dimensions at all in that they do not indicate a measurement. Rather they annotate known co-ordinate points. The DIMORDINATE command is used to indicate the X and Y ordinate values at any point.

The Ordinate Dimension Command

Toolbar Ordinate Dimension
Pull-down DimensionOrdinate
The Ordinate command is used to annotate co-ordinate points with X or Y values. This may be useful for setting-out on site plans.

Command Sequence

Select feature: (pick the point to annotate)
Leader endpoint (Xdatum/Ydatum/Mtext/Text): (pick endpoint or use one of the options)
By default a vertical leader will display the X ordinate and a horizontal one will display the Y ordinate. However, you can use the Xdatum and Ydatum options to override this default.
Ordinate Default Ordinate Ydatum
Ordinate Default Ordinate Ydatum
In the illustration above, the building corner on the left has been annotated with X and Y ordinates using the default method. The one on the right has a Y ordinate which has been forced to display in a vertical position using the Ydatum option. You could also use the Text or Mtext options to clearly describe the point you are annotating.

Annotation with Leaders

Ordinate dimensions are not really dimensions at all in that they do not indicate a measurement. Rather they annotate known co-ordinate points. The DIMORDINATE command is used to indicate the X and Y ordinate values at any point.

The Leader Command

Toolbar Leader
Pull-down DimensionLeader
Keyboard LEADER
The Leader command can be used to annotate any point on a drawing. The command sequence below was used to draw the leader shown in the illustration above.

Command Sequence

Command: LEADER
From point: (pick the point to annotate)
To point: (pick vertex point)
To point (Format/Annotation/Undo)<Annotation>: (pick end point)
To point (Format/Annotation/Undo)<Annotation>:Return
Annotation (or press ENTER for options): Corner ofReturn
MText: buildingReturn
MText: Return (to end)
Unlike other dimension commands the leader and annotation text are drawn as separate objects. So, if you need to move or edit the text, you can do so without affecting the leader line.
As you can see by the command line, there are a number of options with this command including "Format" options which include "Spline". Experiment with these options until you understand them.

Editing Dimensions

The dimension edit commands, DIMEDIT and DIMTEDIT are used primarily to adjust the position of the text part of a dimension. This is usually only necessary if the drawing is quite complex and the dimension would read more clearly if it were in a different position.

The Dimension Text Edit Command

Toolbar Dimension Text Edit
Pull-down DimensionAlign Textoptions
The Dimension Text Edit command is used to modify the text position of any single dimension.
DIMTEDITThe command can be used to position the text dynamically (this is the default)or one of the options can be used for a specific type of movement. For example, the dimension shown on the right has been modified by dynamically moving the position of the text and then the text has been rotated using the Angle option.

Command Sequence

Select dimension: (pick the dimension you want to edit)
Enter text location (Left/Right/Home/Angle): (pick a new position or use an option)
The results of the four available options are shown in the illustration below.
DIMTEDIT Options The Left option moves the text to a left justified position within the dimension.
The Right option moves the text to a right justified position within the dimension.
The Home option returns the text to the home position after it has been modified.
The Angle option enables the text to be rotated about its center.

The Dimension Edit Command

Toolbar Dimension Edit
Pull-down DimensionOblique (other options are duplicated in DIMTEDIT so don't appear)
Keyboard DIMEDIT
The Dimension Edit command can be used to modify and change the text of any number of dimensions. The command could, for example, be used to add a standard prefix or suffix to a number of dimensions.

Command Sequence

Command: DIMEDIT
Dimension Edit (Home/New/Rotate/Oblique) <Home>: (choose an option)
Select objects: (pick one or more dimensions)
Select objects: (pick more or Return end)
The command sequence will vary depending upon which option has been chosen but the results of the various options are illustrated below.
DIMEDIT Options The Home option returns dimensions to their home position.
The New option displays the Multiline Text Editor. The changes you make to the text will be applied to all selected dimensions so it is important not to delete the "<>" marker from the text string. Deleting this marker will remove the values from all selected dimensions.
Isometric DimensionsThe Rotate option can be used to rotate dimension text about its center point. It works in exactly the same way as the Angle option of the DIMTEDIT command except that you can rotate any number of dimensions at once.
The Oblique option is used to set the dimension lines at an angle. This option can be very useful when you are dimensioning a drawing in isometric projection (see the illustration on the right). In this case the drawing has been dimensioned using the Aligned command and then the oblique angle modified to suit the dimension position. This usually means setting an angle of 30, 330 or 90 degrees depending upon the dimension orientation. If you are creating details in isometric projection make sure you are using the isometric snap/grid option for greater efficiency. For more information on drawing in isometric projection and the use of the isometric snap grid.

Dimension Styles

Dimension styles are the main method used to control the way dimensions look. Using styles you can change the text font, the arrow head style, the relative position of the text, the scale of dimensions and many other parameters. Styles are created using the DIMSTYLE command.
Dimension styling is a relatively complex area of AutoCAD and the finer points are beyond the scope of this tutorial. However, the main points which will enable you to create clear, good looking styles are set out below.

The Dimension Style Command

Toolbar Dimension Style
Pull-down DimensionStyle…
Keyboard DDIM short-cut D
Dimension Styles Dialogue BoxThe Dimension Style command can be used to change the appearance of dimensions. The best method is to create a new style before you start creating dimensions so that you can leave the STANDARD style as a default option. Having created a new style from STANDARD you can then apply any modifications you generally require to the parent style and then more specific modifications to the child styles in order to create a style family.
Dimension styles are created using the Dimension Styles dialogue box. The dialogue box is shown on the right. As you can see from the dialogue box, a style is applied to a family of dimensions. By default, any style changes are made to the parent. Each style parent has six child styles. The child styles, Linear, Radial, Angular, Diameter, Ordinate and Leader can be used to modify the parent style when that particular type of dimension is used. For example, you may like to use a tick rather than an arrow head for your dimensions but this isn't really appropriate for a leader, so the Leader child style can be changed so that leaders will always be drawn with an arrow head whilst all other dimensions of the same style family are drawn using ticks.

Creating a new style

To create a new dimension style, make sure the STANDARD style is the current style, click in the Name edit box and type the name of the new style you wish to create. Click the Save button. You will see a message in the lower left corner of the dialogue box which says "Created name from STANDARD" where name is the new style name which you typed. The new style is automatically set as the current style. You may rename the new style if you wish, simply by typing a new name in the Name edit box and clicking on the Rename button.
The new style which you have created is identical to the STANDARD style, so you must now modify your new style so that it can be used to create dimensions which conform to your own requirements. Style changes are made in three categories, Geometry, Format and Annotation. As you can see from the Dimension Styles dialogue box, each category is represented by a button which leads to a dialogue box which is used to modify the settings in that particular category.
Geometry Dialogue Box

Setting the Arrow Head Type

Selecting an Arrowhead TypeThe style of arrow heads is set using the Geometry dialogue box, illustrated above. As you can see, the STANDARD style has Closed Filled arrow heads as a default.To change the arrow head style for a new dimension style, make sure the style is current and that the "Parent" radio button is selected (this assumes you are not modifying a child style), click on the "Geometry…" button and select a new arrow head type from the "1st" drop-down list.
Once selected the new arrow type is illustrated in the dialogue box. If you require different arrow heads at each end of your dimensions you can set the other type using the "2nd" drop-down list. Click on "OK" to return to the Dimension Styles dialogue box.

Dimension Scale

When you are working with drawings which will be plotted at different scales, you will need some way of changing the scale of the dimension lines relative to your drawing so that they always appear the same size, irrespective of plotting scale. You can achieve this by using the Scale variable. This option is also available from the Geometry dialogue box. The default value is set to 1.0. The larger the value the larger the dimension will appear. For example, a value of 2.0 would double the text height and the arrow size. To change the scale of dimensions, simply type the required scale in the "Overall Scale" edit box. Try changing the scale factor and check the results. The scaling applies to individual styles, so you could create different styles with different dimension scales to be used for different plotting scales.
Note that changing the scale of dimensions does not affect the dimension value, this is always calculated in drawing units.

Setting the Text Location

Format Dialogue BoxTo change the text location click on the "Format…" button in the Dimension Styles dialogue box. The Format dialogue box is shown below. By default the horizontal justification is set to "Centred" and the vertical justification to "Above". This means that the dimension text will appear centred above a horizontal dimension line and centred left of a vertical dimension line. To have the text centred within the dimension line, click on the down arrow of the "Vertical Justification" pull-down list to reveal the options and click on "Centered". The illustration changes to reflect your choice. Click on "OK" to return to the Dimension Styles dialogue box. You can see the result of this action by looking at the illustration below. Experiment with the Horizontal Justification and Vertical Justification options to see what results they give.
You can also use Text the option in this dialogue box to change the text orientation in aligned dimensions. By default all dimension text is aligned with the dimension. This option allows you to force text to appear horizontal, irrespective of the orientation of the dimension. You have independent control over dimension text which appears inside and outside of the dimension lines.
Vertical JustificationThe illustration on the left shows a dimension with vertical justification set to "Above" (far left) and to "Centred" (near left).

Setting Text Style and Units

Text style and units are both set using the Annotation dialogue box, illustrated below. To set a text style to a dimension you must first have created the style using the Text Style command (FormatText Style… from the pull-down menu). To assign the text style to a dimension style, click on the "Annotation…" button in the Dimension Styles dialogue box, click on the drop-down list in the "Text" area of the Annotation dialogue and select the required text style from the list. Click on "OK" to return to the Dimension Styles dialogue.
Annotation Dialogue Box AutoCAD gives you the option to automatically include a unit prefix or suffix with the dimension text. For example, you could set the dimension style in such a way that it created dimensions with "m" to indicate metres after each dimension text. Most usually, dimensions are drawn without units displayed but with a note on the drawing indicating the units used, such as "All dimensions in metres". However, you may have a drawing where different units are being used for different elements of the drawing. In such a case it is a good idea to include units to avoid confusion. Remember that the main idea behind dimensioning is to give the maximum amount of information in the clearest and most concise way. To add units to a dimension style, click on the "Annotation…" button in the Dimension Styles dialogue box and enter the required unit character(s) in the "Prefix" and/or "Suffix" edit boxes of the "Primary Units" area of the dialogue box. For example, if you wanted to display metres, you would type "m" in the "Suffix" edit box.

The Dimension Update Command

Toolbar Dimension Update
Pull-down DimensionUpdate
Keyboard DIM Return UPDATE
The Dimension Update command is used to apply the current dimension style to existing dimensions. You can use this command to change the style of a dimension. Unlike text styles, dimension styles do not automatically update when the style is changed. The UPDATE command must be used to force dimensions to appear in the current text style.

Command Sequence

Command: DIM
Select objects: (pick dimension to update)
Select objects: (pick more dimensions orReturnto end)
Dim: (press the escape key, Esc to return to the command prompt)

Tips & Tricks

  • Always attempt to use the least number of dimensions in order to provide the maximum amount of information.
  • Avoid giving duplicate information. For example, if you use a number of running dimensions along the length of an object, it is not necessary to include an additional dimension for the whole length. In the illustration on the right the "50" dimension is unnecessary because it gives no extra information and simply duplicates that which can be inferred from the "20" and "30" dimensions. This will also avoid any ambiguity which may arise from inaccurate dimensioning.
  • Sometimes it may be more appropriate to add notes to your drawing which include dimension information rather than attempt to dimension small or complex items.
  • If you do not include any units information with your dimensions you must always add a note to your drawing such as "All dimensions are in millimetres" to make it absolutely clear.