My son likes working calves, but we don't have an easy way to isolate them. He's been doing standing calf raises with the barbell, and also one-legged calf raises while holding a dumbbell, but I wanted a way for him to really hit them. I believe in the big, compound exercises, but machines are a great way to work muscles in isolation. A calf machine is a good example of this. So, still flush with success a year after constructing our power rack, we we decided to build our own calf machine. I...