This is a forum for EDA, and there are also forums for physics (physicsforums.com), for programming (stackoverflow.com), for mathematicians (mathoverflow.net).
But, is there any dedicated forum for mechanical engineering? Anyone familiar with them?
Try this one "www.eng-tips.com", you will find professional engineers there, but be sure to read their form rules 1st, or they will delete your account.
A lot of engineering forums tend to centre around the software used such as solidWorks, the problem is you have to be a SW user and on maintenance to access the site. These sites have advantages, but also one big disadvantage in that only the paticular package users will use the forums.