Here is my Latest PAWPAW project. I call it a Ballpen Playpen. It could be utilized as a playpen, but was originally built to be a ballpit. Just fill it up with some play balls, a worthy participant, and let the fun begin. All of the sides are removable to make it easier to move if need be. The base even has 2 small wheels mounted so you can lift it up on one side, and roll it around. I also put little plastic feet on the bottom of the base so the base does not sit flat on the floor. It measures about 48×48 and the sides are about 18” high. The cost believe it or not was around $100 or so, in case the wife is watching. I used 1 1/8” wood dowels, and used Electrical type “U” connectors to mount the sides to the dowels.
As you can see in the pics I HAD to do some detailed testing. I enjoyed testing so much, I may build one for myself.