| 1 | //////////////////////////////////////////////////////////////////////////////////////////////\r |
| 2 | // Paraboloid module for OpenScad\r |
| 3 | //\r |
| 4 | // Copyright (C) 2013 Lochner, Juergen\r |
| 5 | // http://www.thingiverse.com/Ablapo/designs\r |
| 6 | //\r |
| 7 | // This program is free software. It is \r |
| 8 | // licensed under the Attribution - Creative Commons license.\r |
| 9 | // http://creativecommons.org/licenses/by/3.0/\r |
| 10 | //////////////////////////////////////////////////////////////////////////////////////////////\r |
| 11 | \r |
| 12 | module paraboloid (y=10, f=5, rfa=0, fc=1, detail=44, x, hi){\r |
| 13 | // y = height of paraboloid\r |
| 14 | // f = focus distance \r |
| 15 | // fc : 1 = center paraboloid in focus point(x=0, y=f); 0 = center paraboloid on top (x=0, y=0)\r |
| 16 | // rfa = radius of the focus area : 0 = point focus\r |
| 17 | // detail = $fn of cone\r |
| 18 | \r |
| 19 | hi = (y+2*f)/sqrt(2); // height and radius of the cone -> alpha = 45° -> sin(45°)=1/sqrt(2)\r |
| 20 | x =2*f*sqrt(y/f); // x = half size of parabola\r |
| 21 | \r |
| 22 | translate([0,0,-f*fc]) // center on focus \r |
| 23 | rotate_extrude(convexity = 10,$fn=detail ) // extrude paraboild\r |
| 24 | translate([rfa,0,0]) // translate for fokus area \r |
| 25 | difference(){\r |
| 26 | union(){ // adding square for focal area\r |
| 27 | projection(cut = true) // reduce from 3D cone to 2D parabola\r |
| 28 | translate([0,0,f*2]) rotate([45,0,0]) // rotate cone 45° and translate for cutting\r |
| 29 | translate([0,0,-hi/2])cylinder(h= hi, r1=hi, r2=0, center=true, $fn=detail); // center cone on tip\r |
| 30 | translate([-(rfa+x ),0]) square ([rfa+x , y ]); // focal area square\r |
| 31 | }\r |
| 32 | translate([-(2*rfa+x ), -1/2]) square ([rfa+x ,y +1] ); // cut of half at rotation center \r |
| 33 | }\r |
| 34 | }\r |
| 35 | \r |
| 36 | \r |
| 37 | //paraboloid (y=50,f=10,rfa= 0,fc=1,detail=120);\r |
| 38 | paraboloid (y=50,f=10,rfa= 0,fc=1,detail=120);\r |