The last thing I found was reference points and reference lines. In drawing the cam for this engine the center of the shaft was Y=-.25" and that is where most of the dimensions were referenced from. Also I needed reference lines at 15° from that point. That is not available with Atom. I had to first enter the points and the lines and then change them to reference figures. Actually one of the things I most dislike about Alibre is the dimensioning on the drawings. It is difficult to place the text and the lines where I want them. The program thinks that it knows better than I do what I want. That is probably also true on other 3D programs. Another frustration is when making a sketch part I end up placing dimensions all over the place trying to find which dimension I am missing to fully define the sketch.
Ah, I know what the problem is with Atom: There are a couple possible solutions to the angle problem, (of course, I don't really know for sure what problem you're having), the first and most important would be to make a new drawing plane at an angle usually at 90deg to the part you want to draw. Do you use that ability, to make planes at angles and offsets?
Your other problem is one I encounter when I need to make a sweep, either building something like a curved pipe or cutting something in an odd shape. That's one that I have a difficult time with as the reference line which the sweep follows has to be perfectly lined up with the object to sweep. I doubt that your problem is exactly what I am talking about.
Anyway, about the dimensioning. In Atom there is an automatic dimming and one in which you place each dim manually. Turn off the automatic one, don't use it. It is not very good. When dimming by hand, I come up against one dimming prob in atom, and that is I cannot, in all cases, place the arrow line left or right of the arrow==it's always one but never the other. The "other" is my choice. It's minor but still irritating. I'm sure your prob is not the same as mine,. and in that case, I am not a liscenced therapist, and you will have to go to your own shrink
![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
P.S. You do know there are built in reference lines and circles? I use them all the time. For instance, If I need a bolt hole at a certain distance and angle from a point, I will use the ref circle for the distance from the point and then draw a ref line at the angle which automatically tells the angle and distance of the ref line being drawn.