Tuesday, August 17, 2010

CAD packages

Some basic knowledge of CAD packages never hurt anyone. Two of the most common ones used in industry are AutoCAD and SolidEdge. Most of the time you will just need to take measurements from some diagrams rather than build a complete model.

AutoCAD has a command line interface (from way back in the DOS days). Two useful commands for measurement are:
  • di - Measure a distance between two points
  • id - Print the coordinates of a point of interest

Other things you might find yourself doing include drawing lines and circles, which are all relatively self-explanatory. Occasionally you need to measure something relative to a reference line or base line that you want to project through the whole drawing. You can do this by using the 'extend' option to lengthen the line. Simply choose the 'Extend' option from the modify menu and draw a line to represent the boundary of the lines extension, right click, and select the line you wish to lengthen. AutoCAD will lengthen the selected line up to the boundary you specified.

Like Photoshop AutoCAD also has layers which you can work with. You can turn layers on/off by clicking on the lightbulb function.

With SolidEdge you can use the dimension menu to make measurements (Make sure you are working on the correct sheet!). These can be either horizontal/vertical, by two points, or you can select an element in the drawing to use as the axis (easier than in Autocad!).


Adrian said...

To create a perpendicular line from a reference line type:
Specify angle (A)
Specify reference (R)
Select the line that you want to use as a reference (where you want a perpendicular line)
The enter the angle (e.g. 90 degrees)
Then specify the point the line should go through

You may need to Trim the line to make sure you get what you want.

Adrian said...

Its often easier to make dimensions by resetting the coordinate system, so:
ucs - sets a coordinate system
dli - measures a linear dimension in the current coordinate space

Adrian said...

draw a parralell line with the osnap (PARA), start a line (LINE), then click the start point, move the mouse over the line you want to be parallel to, and wait for the 'parallel' icon to appear, then move the cursour to a point approximately parallel to the line you selected, and it should snap to parallel. (PERP) for perpendicular lines.