Dimension styles

- [Instructor] The whole point of drafting is to show someone how to build the object and build it repeatedly and consistently. To do this, the backbone of drafting is dimensioning. There are many rules for drafting dimensions, and while I won't get into proper dimensioning technique here, I will explain how to use the tools that AutoCAD for Mac provides so that we can detail all the pieces of our drawings. To start, we can look at the dimension tool set, found here, and see some of the tools that are available to us. AutoCAD uses what are called dimension styles to preset all of the variables available to a dimension, things like text size, arrowheads, offsets, and so on.

To create our own style, we can either click on dimension style here, or we can go up under the menu and click dimension style. Here, in the dimension style manager, we can create our own style. Annotative styles, seen here, allow you to change the dimension scaling for use in model space. But since we are going to concentrate on putting our annotations in paper space, we're going to use a standard style. We'll create our own style using the plus button here, which I'm simply going to call, LYNDA.

We have the option for starting with another previous style, and we're going to choose standard and click continue. Here, we can see all the tabs for the different components and variables for our dimension styles. We're not going to go through every single option, but I do want to highlight a few of them. Starting in the line tab, I typically change my color, line type, and line weights, so that they are controlled by the layers. We can also choose our baseline spacing, which we'll talk about a little bit later, and we can choose the extension beyond the dimension lines here for the extension lines, as well as the offset from the origin.

Remember that the extension lines are the lines that are perpendicular to the part being dimensioned, and the dimension lines are parallel to the part being dimensioned. Dimension lines typically are the ones that have the arrowheads and the actual dimension inside of them. Symbols and arrows allows us to choose the symbols that we want to use for our arrowheads. We have quite a few to choose from, including closed filled, architectural ticks, all the way down to creating our own user arrows. We can control the size of the arrows here, as well as the break size when we have overlapping dimensions.

Center marks refers to the center mark symbol, seen here, used in radial and diameter dimensions. We can see a preview of what each one of these looks like by cycling through the radio buttons here. Text allow us to choose a specific text style, as well as a text height. We can also choose the alignment of the text, here, either horizontal, or always read from the bottom of the page, aligned with each individual dimension line, or the ISO standard, which is a line, but the radial and diameter dimensions and any leaders are typically read horizontally.

Fit refers to which part of the dimension is placed outside of the extension lines if not everything will fit. In this case, we can see the arrowheads are actually placed outside the extension lines, because not everything will fit between them. We can also control the overall scale of the dimension here. Units are quite important, so make sure you choose the unit format that you want to use. We have decimal, architectural, and engineering to choose from. Please note that this is separate from the drawing units that we spoke to earlier.

We can also set the precision here, in our case, about two decimal places. Alternate units are quite helpful if you're using any kind of International Drawing Standards or you need to show Imperial and Metric alternates. Finally, tolerances allow us to add symmetrical, deviation, or limits to our dimensions. Once we're done, we're going to go ahead and click on okay. We'll make sure that we use the gear here to set our dimension style as the current style, so any new dimensions we create will be on our current style.

The gear is also used to modify and compare our dimension styles. Now that we've created our style, we can use it to apply dimensions to our drawing.