I recently acquired an old tripod. I am trying to make it a shooting tripod to help my kids. I am trying to mount a ball head, but I can't figure out how to get it attached to this tripod. How do I get this center pole to a 1/4 inch or 3/8 screw? I don't even know what this is called to look for the part. The center pole is about 17mm.
http://imgur.com/a/adWnr3B#zuOKNek
http://imgur.com/a/adWnr3B#9Xm62xM
http://imgur.com/a/adWnr3B#zuOKNek
http://imgur.com/a/adWnr3B#9Xm62xM