Frazer,
Actually it isn't new as far the physics is concerned. I have , as most old geysers have, a graver made from a bit of square hss steel. It becomes a diamond shape beloved by - well, eccentric people. Which is where I came in =LOL!
If I could see properly, I have Model Engineer curvilinear construction which would do the 'Bessie Braddock' legs which you may recall- or those on your Stirling engines of Auld Reekie and Glesgeh.
Incidentally, I used to 'do' Northumbrian small bagpipes and at some bit of almost forgotten past I worked on a Boxford with 'a bit of round bar' held in the 4 position tool post. The way to make funny shapes?
True, the Eccentric one is sophisticated = and the sliding could come from a top slide which -- laughingly- come from removing a top slide when using this Turnado thing.
As soon as things quieten down, I'm half blind, deaf, COPD'd and being filled with B-12 and Formic or did he say Folic acid, I'll unearth the article.
Kindest regards
Pins and needles