How many years of industrial experience needed for a Mechatronics Professor? I have a Bachelor's in EE and Master's in Automation and 3 years experience, including 2 in software development. For me, an academic career would be both more meaningful and professionally rewarding in its flexibility. 

I think someone with experience but without formal qualifications could teach a subject such as mechatronics well. 

How I might switch to teaching mechatronics? Should I stay in industry for a few more years and then move straight to being a full-time professor? Or, should I work part-time for a lest prestigious college and try to progress incrementally?

Note:
I don't want to obtain a PhD. Rather, I'd prefer to obtain the necessary qualifications while part-time, while working as a professor.
Your answer seems to confuse teaching with being a professor. One can teach without being a professor. Furthermore, and although this may be controversial, I think the quintessential characteristic of a professor is a scholar who can carry on substantial independent research. 

Neither teaching skill nor experience in industry counterbalance the lack of that.