I'm in college working towards a degree in Mechanical Engineering, so far I've only made it through physics 1 and calculus 2, but I've been building race cars and pulling trucks and tractors since i could hold a wrench. I work for a guy that builds super modified four wheel drive pulling truck frames. I've recently downloaded auto-cad inventor and am slowing learning how to draw frames. So I was wondering if anyone could help me figure out how to add up the different forces, so I could run stress simulations on the frames. Any help will be greatly appreciated, thanks.