OP

Quoted from twenty84:

Part of the reason we wanted to sell at a discount at first was because these really have a nice feel to them which is difficult to get across on the web. We figured once they got in the hands of collectors they would gain popularity.
The rods are press fit into the ball using a hydraulic press which itself is probably enough to keep it from ever coming off. For good measure a drop of epoxy is put on the end prior to fitting it which makes it pretty solid. I wanted to see how solidly it was attached and have tried putting the rod in a vice and put a wrench over the ball and knocking it off with a 9 lb. hammer. It is essentially impossible to get the ball off the shaft without destroying it.
Actually I first thought of making these just for my own machines. The first one probably took my an hour in the machine shop to make: it is easy to break bits drilling into these and it generates a lot of heat so you need to go slow. Friends saw what I made and wanted them but there was no way it was economically feasible the way I was doing it. I had some local machine shops quote the job but it still was expensive enough that I felt like it would be too expensive for a lot of people. There are actually large shops that specialize in drilled steel balls for the automotive industry but for them to be interested you have to order a lot of them. So that's what I did, but I had to order more than I could sell just to friends so I decided to make a go of it as a business.