Would you recommend the use of IronCAD for my automated machine building project?
Sure, if you AM project has baseline system that are engineered to order, then IronCAD is your only choice. It's actually designed for such automated machine projects. You will enjoy working with it, it is hustle free with few knobs and switches.
http://www.tecnetinc.com/Worst%20to%20Best%20CAD%20Systems!%20-1.html according to this website IronCad is 9th worst CAD and nothing better shown in this list.
I used Ironcad and found it much easier than any other tool. The user forums are real helpful for getting up to speed. Go with it
What are you planning on doing with the CAD package? Home modeling, practice for future potential employment, starting a small company, or something else? The usage case can have a big impact on what CAD package is best.
The most important measure of "good" is how intuitive the program is to you. If you have to fight the program to make something, it will never be "good" despite what reviewers claim.
I'd say first off, do you like it? What works for one person workflow wise may not work for you Second, what's used in the area, look up some major companies where you are and see if they're hiring and if they do what they use.
What are you trying to accomplish? If you are new to CAD, TinkerCAD is pretty simple to understand and everything is graphical.