Datum Lines

Video: https://youtu.be/zGXsA3yHruw

Instructions from Video:

We will learn about Datum lines and how to add them to your elevations and sections automatically upon insertion to document the various heights in a model. The datum lines can be personalized to fit your office standards. Let’s first review the settings associated with datum lines and how they can be altered.

Select Settings>Document Settings.

The datum lines are broken into separate parts. The Datum Mark, the Leader Lines, The Datum Lines and the text that appears on the leader lines.

In the Document Settings dialog box, select Datum Lines.

Here all the datum line settings are listed. At the very top of the options is Layer. The lines and text for the datums are stored on a layer that can be turned on an off at your convenience. As a default, the datum elements are put on the layer “CAD”. By clicking on the word CAD a dropdown arrow will appear and allow you to select an alternate layer.

Next, it lists the options for the Datum Marks. The Datum is a mark that you can put on the left, right or both sides of the line that it draws. The Datum Marker is a block that is there as a default. You can create another block as an alternative or set it to None to have nothing appear at the end of the lines.

The leader lines are the lines that are beyond the datum lines. They can be on either side of the datum lines or just one side. The length of the line should take into consideration the length of the text that will be on the line. If you have a long string of text you may want to extend the line longer than 5’. The lines can be any colour, line type and weight that you want or they can follow the settings of the layer, in our case, CAD, that has a red colour, a continuous line and medium pen weight.

The datum lines can be either on or off. You may prefer a cleaner look without the line running through the model and just have the leader lines on the edge of the model. Extension is how far past the model do the lines extend, again you can personalize this to any length. The Colour, Line Type and Line Weight again follow the layer “CAD” as a default, but you can change them to suit your needs.

Lastly, there is the text that is inserted. Where do you want the Description text to rest, Above or below the line and on the left or on the right of the model? The elevation height also has the same options. Just make sure you do not select the same for both or the text will overlap. The style of text for both is determined by the text style. You can select an existing style or develop a new style just for datum lines. The alignment of the text is associated to the leader line. Is the text aligned to the left, in the center of or right-aligned to the leader line?  Again, your choice, just make sure that the leader line is long enough for your longest text string. Click OK to accept your changes.

Now let us insert an elevation to see how the datum lines look. I am currently on the “2 Elevations” worksheet tab. This environment is strictly for creating views of your model, adding additional information, and printing the sheets for a permit.

Select Insert>Smartviews>Define Smartviews or select the Define Smartviews icon under the Insert tab.

In the Insert View dialog box, select the Elevations tab.

As a side note, the Sections tab will also have the same datum settings. In the Elevations tab there are options for the datum lines that can insert automatically with the elevation. You can set “Yes” or “No” to inserting the lines. Then beneath that specify what lines you want to appear. I am going to say yes to the Floor Level and the Head Height lines as I need their heights with the elevation drawings. The last options are for which locations to include. You may not want the datum lines on every location, especially if you have created special locations to house extra information. Only turn on the locations that are important to the document. The settings button takes us back to the Document Settings so we can make any changes we may need before we insert the elevation.

Click Insert.

The elevation will attach to your cursor, left click to set in on your drawing sheet. The datum lines are inserted with the elevation.

I hope that makes your work one step easier!