Surface graphing question

*To*: mathgroup at smc.vnet.net*Subject*: [mg64560] Surface graphing question*From*: János <janos.lobb at yale.edu>*Date*: Wed, 22 Feb 2006 05:58:49 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Hi, Thinking about something else, I ran into this problem below. Let's say I have two concentric circles in a plane with radiuses rsmall < rbig. I create a circle involute / see http:// mathworld.wolfram.com/CircleInvolute.html/ using rsmall. The involute will turn 1< n times before it crosses the rbig circle. Then I erect a cylinder above rsmall and place a cylindrical stick with radius 0<= rstick << rsmall and length "l" <= (rbig-rsmall) to the point where the involute is "coming out" from the bottom of the cylinder. The stick is parallel with the cylinder and it is touching it from the bottom of the stick to the top of the stick at every point of that line where they touch each-other. Then I start to move the bottom of the stick on the involute outwards and I make sure that the projection of the stick down to the plane of the circles are always radial. During the first revolution of the involute the upper end of the stick is still touching the cylinder. I do it till the bottom of the stick gets to the point where the involute crosses the circle with rbig. The stick will create a surface in space with rstick thickness and after one revolution the upper end of the stick will travel on this surface. How to graph such a surface and create a cut-out of it with different planes ? /Optimally I am looking 3 sticks moving on 3 involutes parallel where the involutes are 120 degree apart, but I would be happy to start just with one now :)/ Any good pointer to related web pages would be also appreciated. Thanks ahead, János ---------------------------------------------- Trying to argue with a politician is like lifting up the head of a corpse. (S. Lem: His Master Voice)