topic Re: Dimensions needed in Inventor Forum

topic Re: Dimensions needed in Inventor Forum https://forums.autodesk.com/t5/inventor-forum/dimensions-needed/m-p/5744003#M366863 You seem to be correct that it isn't explicitly mentioned in the help files.  Have you looked at the tutorials on the "Get Started" tab?  This concept is taught very early in most Inventor training courses, and I expect it is somewhere in the sketching-related tutorials as well.  I am a little surprised that it isn't mentioned (and maybe it is buried in there somewhere), but maybe the writers of the help files overlooked it because it is typically covered in training.   One thing that is commonly confusing to new users is that the name of the field is somewhat misleading.  It does not literally mean "number of dimensions."  It actually represents the number of unconstrained degrees of freedom.  Constraining this geometry (and reducing the "dimensions needed" count to zero) typically requires a mixture of actual dimensions and geometric constraints.  For most of your construction lines, simply constraining the endpoints Coincident to the lines of the large rectangle would fully constrain them without adding any actual Dimensions (as Carlos did in the Screencast he posted).   Forgetting about constraining construction lines is an extremely common new-user mistake.  Also, I would point out:   <UL> <LI>Two of your construction lines are coincident with an origin plane.  If you had Projected the plane (or axis) instead of drawing a construction line, it would be behaving exactly as you said you were expecting construction lines to behave.</LI> <LI>Some of your construction lines are unnecessary, as you could delete them and snap the dimension to a tangent point of the arc or circle instead.</LI> <LI>Other construction lines are unecessary because they could be replaced by a horizontal constraint between points (such as the center points of circles).</LI> </UL>   Hope this helps. Mon, 27 Jul 2015 22:40:46 GMT jtylerbc 2015-07-27T22:40:46Z