The linear ratio of callout and the global proportion in AutoCAD

We know that drawing graphics in AutoCAD is proportional, but when dimensioning, there are two dimensions associated with callouts in the property manager: Callout linear proportions and callout global proportions. As pictured.

If we select the "Callout-style" menu and open the callout style manager, you can see the option to adjust the callout's linear ratio under the main Units tab. Under the Adjustments tab, you can see the option to adjust the global scale of callouts. At the same time, they correspond to two system variables DIMLFAC and Dimscale, modify the values of these two system variables, also equal to adjust these two proportions.

Some beginners in the new or modified callout style, often confusing or confusing, resulting in the proportion of drawings errors.

So, why is there a two ratio of dimensioning? What difference does it have? Here is a description of their role and differences to prevent misuse.

Mark the difference between the linear scale and the marking global proportion

Generally in the drawing, depending on the situation and the use of different proportions, which involves the adjustment of dimensioning dimension values.

An example is provided:

If the graphics are drawn in CAD by 1:1 and the callout scale is set to 1 in the callout style, then the size callout, the default dimension value given by the system, is the actual value of the object.

However, in the case of proportional n:1, the graph is scaled down, if the default dimension value given by the system according to the annotation is given, according to the value of the retraction.

If you want to no matter how the graphics to shrink, the system gives the default size values are based on the actual real value of the callout, it is necessary to adjust the callout linear ratio.

Specific examples Show

For example, a figure in a size, the real value is 10, in accordance with 2:1 scale, in the CAD inside the length of 20, the scale factor is 1 of the case to mark, the system automatically to the vacancy province value is 20, so to adjust the proportional factor to 1/2.

As a result, the corresponding callout ratio is adjusted to 1/n when drawing the graph according to N:1.

And this ratio of adjustment, is to set or modify the callout linear ratio.

Another proportion-marking the global scale, and the dimension value of the callout is independent, mainly control the size of the annotation elements, distance or offset.

Now in order to unify and standardize the drawing format, many companies have specified their own drawing templates, which make the basic requirements for some drawings.

For example, in a drawing template, the template stipulates that the text height in the callout element is 4, and the arrow size is 2.5, which is the default callout with a global ratio of 1.

If the callout's global scale is adjusted to 2, the dimension value of the callout is not affected, and the associated dimension element-the height of the text and the size of the arrowhead-becomes one times the same.

The figure is an example of changing the global scale of annotations.

It can be seen that the dimension value of the callout has not changed, and the callout text and arrows magnified, which is the impact of labeling the global proportions.

So, after understanding the difference between the two ratios above, when you create a new graphic or template, you drop the page size, drawing units, text formatting, colors, line styles, and so on, setting the callout style, adjusting and setting the callout scale according to the actual proportions used by the drawing and the requirements of the graphic annotation elements.