{"id":4,"date":"2008-10-10T20:57:48","date_gmt":"2008-10-10T19:57:48","guid":{"rendered":"http:\/\/www.hilltop-cottage.info\/blogs\/adam\/?p=4"},"modified":"2008-10-10T21:32:23","modified_gmt":"2008-10-10T20:32:23","slug":"test","status":"publish","type":"post","link":"https:\/\/www.hilltop-cottage.info\/blogs\/adam\/test\/","title":{"rendered":"Paradoxical Cones – the Uphill Roller"},"content":{"rendered":"

I came across an account of the “uphill roller<\/a>” in a book by Julian Havil, “Nonplussed!”. The basic idea is that two cones, joined at the bases, will appear to roll uphill on a pair of diverging rails if the combination of the angles of the cones, slope of two rails and divergence of two rails is within certain margins. Julian’s article<\/a> explains the mathematical analysis and gave a simple inequality.<\/p>\n

That looks cool, I thought, and the challenge of machining two con-joined cones appealed too.<\/p>\n

I decided to design an adjustable set-up that would demonstrate conditions when the cones would appear to behave paradoxically and conditions when the would not. Somewhat to my surprise the finished article worked as inteded.<\/p>\n

Downloads:<\/p>\n