[Andy A.]

I think one of the most important skills in Inventor, and any modeling software, is proficiency with constraints.

A good CAD jockey is one who lets constraints do the work for him. I am always amazed by how quickly and easily my instructor can sketch out complex geometry in a sloppy manner, and then using a handful of constraints force it into just the shape he wants. And then, by changing only a few dimensions, he can quickly change sizes and such as the design entails.

By comparison, my designs are clumsy. They take a long time to sketch because I am still clinging to my AutoCAD practices of making the correct geometry by tracing off lines and dimensioning every single line. Even worse, by the time I do get the shape I want, changing it requires almost as much work as creating it in the first place! I could liken it to using comments in programming. A poorly commented program is one that only one person can use, and is difficult to change. A well commented program can be modifyed and improved upon 5 years from now.

This extends equally into the 3d realm, and I believe that the more practice one has making properly constrained sketches, the better your assemblies and features become.

The more I properly use constraints, the easier my life becomes with Inventor. Once you get some basic proficiency with Inventor, experiment with constraints on a sketch. Learn how to quickly and easily turn those green lines black! My rule of thumb is that every time I think "theres got to be a better way to do this" there is, and I need to open up that help file.

My strong advice is to spend plenty of time in 2d sketch mode. When you feel you have that down pat (and it is _not_ just AutoCAD), you will probably have a much easier time with 3d stuff.

-Andy A.