I made one today out of galvanized pipe and two 25 lb plates. the design is something like this: as a side note having just created a 50lb hammer with a 1" handle, it realize I am FAR too weak to use a hammer 100 lbs heavier and an inch thicker (like the 150lb hammer on torque athletic) but shit this thing is fun to swing around. Only took about 20 swings total and I really feel it. for less than 20 bucks in materials (not including the plates) it's something fun to try. Plus, you don't HAVE to start at 50 lbs. and if you don't have standard plates, a thicker handle won't hurt anything (not counting how much harder it's going to be to hold onto). do be aware though, I've already broken my handle at the threads, so sticking a piece of rebar or maybe filling the whole thing with concrete (I hear q-5000 or something is the strongest. the more hardcore forum members will have some left over from their atlas stones), might be helpful, but I've yet to try it.