Ball Opener, Bottom maker, Ball Buster, Part 1

The ball opener or, bottom maker, etc. is a tool that the folk potters of the Carolinas used to turn the big wares they produced day in and day out. It essentially opens the centered clay ball and stops just short of the wheel head making the bottom a consisitent thickness. Whether it compresses the bottom I can't say, I usually go in with my thumb and give it a good thumbing. There are many different ways that you can build this. Here is a shot of my "opener" and how it makes the bottom. What I don't show in this picture is the stopping block that keeps the plunger from going too deep and making the bottom to thin, sorry. I will do another post on that. I built mine based on some drawings in "Raised In Clay" by Nancy Sweezy. Here are some of the drawings from the book showing various options.

My opener frame is attached to the wall and every once in a while I have to move my wheel into place to get the opener centered. But that's not too hard to do and it doesn't affect the opening too much if it's not exactly centered.
Below is a picture of Bill Gordy's wheel showing his ball opener, which is simply an arm with a simple hinge cut into the wood and a pin to help the opener swivel. Kim Ellington's opener is simply a stock wheel barrow handle attached to a swiveling caster where he has removed the wheel and attached his opener arm. Simple is better.
Basically you need up and down action and you need a horizontal pivot/swivel. If your using 20 lbs op clay you have to have a "beefy" piece of wood. You don't want any bending in your arm as you swivel and open your clay ball. (Maybe I should get Ron up here with his YouTube crew, or is it your HisTube crew, no matter) and get this on video? Also, you need to keep the opener out of your way after you've used it. Mine has a pulley and counterweight to raise it and I then swing it out of the way for turning.