Many years ago I visited a company that did nothing but spinning. Several massive spinning lathes, one of which was built into the floor and would handle work of 6ft diameter or so. With that they used to spin cones in stainless steel, of a thickness that I would have said was impossible. The tool used was the usual ball-end, but the handle was fixed to a length (about 8ft) of scaffold pole. I did learn that a lot of force was required, that it was very skilled work, and that practice was the only way to get proficient. Alan MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.