What is Polar Snap Tracking in CAD and how to use it?
The dimensions we see in most drawings are about angles and length, few of us would dimension coordinates. When drawing, we tend to use Object Snap or just enter the length and when the lines of graphic objects are orthogonal, we can just use ORTHO. But what if there is a fixed or regular angle, such as 30 degrees, 45 degrees, 60 degrees. That’s what Polar tracking used for.
We can set a polar increment angle according to our needs, and when we approach the cursor to angles that meet our needs, a faint dashed line which is called polar appears, the cursor is fixed on the polar and we can just enter the distance value, so polar tracking is to specify angles using fixed polar.
Polar is easy to use and the key lies in how to properly set polar increment angle. CAD provides a series of commonly-used increment angle settings, and we can also add more if needed. Right-click the bottom status bar to pop up a dialog box of polar, as shown in the following picture.
Grid snap, Ortho and polar will restrain the angles of the cursor, you cannot have polar and Ortho or Grid on at the same time, if polar is turned on, the Ortho will be automatically turned off.
Click the Polar track button in the bottom status bar or press F10 to quick open polar.
The increment angle is normally set as 30 degrees or 45 degrees, if there are many angle values in the drawing, we can set smaller increment angle such as 5 degrees and 10 degrees, but we could just enter polar coordinates or angle instead of using this method.
After setting the polar increment angle and start drawing, specify the first point, move the cursor, when the cursor approaches the polar increment angle, a polar in feint dashed line appears, as shown in the following picture.
When moving the cursor away from this angle, polar and prompt both appear.
Related polar axis
By default, polar is calculated based on the base angle of UNITS in the dialog box, there is another way to locate: to calculate polar angle based on the straight line drawn in the last segment, this way is usually used for angles between two known lines, as shown in the following picture.
To use this method, we just need to select Relative to the last segment in the dialog box of Polar tracking. Please note that because the default direction of calculating is anticlockwise, the angle of the two lines is 30 degrees, but it displays 150 degrees in the related polar area.
Polar tracking can not only pinpoint the angles, but specify length together with Grid snap, and this is called polar snap. The settings for polar snap is in the Polar and Grid dialog box, as shown in the following picture.
Turn on the polar snap mode and you can set the distance. If the distance is set as 10, turn on the Grid snap, move the cursor along polar to snap points 10, 20, 30, and specify angles and length using polar, as shown in the following picture.
Many users don’t use Grid snap very often, just entering the distance using polar snap tracking will work.
Leave a Reply