I traced a circle on some plywood with a sharpie tied to a string, cut it out with a scroll saw, then for the rounded piece on the bottom I got the biggest wooden drawer pull knob that they had at the hardware store, like one of these (www.amazon.com/Laurey-32601-Natural-4-Inch-Diameter/dp/B000CEMN04/ref=sr_1_11?s=hi&ie=UTF8&qid=1407863982&sr=1-11&keywords=wood+cabinet+knobs) and screwed it into the bottom with a piece of scrap wood as a spacer to raise the board up another half inch off the ground. I also have since put some grippy/sandpaper tape on the top of the board. Overall super cheap and works great!

thanks. will try this:).