Another round corner cube library

thingiverse

I have written this library while I was working on a scad project and thought it might be usefull for someone else. It uses the build in openscad $fn functionality of spheres and cylinders to smooth out cube corners. Version 2014-09-20: Initial release Version 2014-10-05: Performance updates Instructions /* Another round corner cube library by towa Version: 2014-10-05 rcorn_cube(size, r, f, center) size : size of the object like in cube-function r as scalar : corner radius of a sphere r[r, h] : corner radius of a sphere and height of an additional, overlayed cylinder r[r, h, t] : corner radius of a sphere, height of an additional cylinder and vertical translation of the cylinder f : number of facets of sphere and cylinder center : false if the object should not be centered Examples: translate([0, -60, 0]) rcorn_cube([50, 40, 30], 10, 8); translate([0, 0, 0]) rcorn_cube([50, 40, 30], [8, 4], 24); translate([0, 60, 0]) rcorn_cube([50, 40, 30], [10, 5, -5], 64); */ // include in your project with "use ;" for (i = [0:2]) { translate([i*70, -60, 0]) rcorn_cube([50, 40 - 2*i, 25 - 4*i], 10, fn = 8, center = false); translate([i*70, 0, 0]) rcorn_cube([50, 40 - 4*i, 25 - 8*i], [8, 4], fn = 24, center = false); translate([i*70, 60, 0]) rcorn_cube([50, 40 - 6*i, 25 - 12*i], [10, 5, -5], fn = 64, center = false); } function gz(val) = (val > 0) ? val : 0; module corner_transl(i, size) { translate( [(floor(i ) % 2 == 0) ? -size[0] : size[0], (floor(i/2) % 2 == 0) ? -size[1] : size[1], (floor(i/4) % 2 == 0) ? -size[2] : size[2]]) children(); } module rcorn_cube(size, r, fn, center = true) { //%cube(size, center = center); // check if cube is inside boundaries r = (len(r) == undef) ? [r] : r; // force r to be an array sh = size / 2; // vector with half of the object size shlim = [(r[0] > sh[0]) ? sh[0] : r[0], (r[0] > sh[1]) ? sh[1] : r[0], (r[0] > sh[2]) ? sh[2] : r[0]]; // intersection boundaries // properties of a low resolution sphere rs = r[0] / cos(90 / ceil(fn / 2)); // radius to adjust a given height of a low resolution sphere redg = (ceil(fn / 2) % 2 == 0) ? r[0] : rs; // the edge radius of the low resolution sphere sc = 360 / fn; // corners of a low resolution sphere // horizontal distance the sphere or cylinder has to be moved // inside the object to be in the specified boundaries md = redg * cos(min(abs(135 % sc), abs(135 % sc - sc), abs(135 % sc + sc))); shm = [gz(sh[0] - md), gz(sh[1] - md), gz(sh[2] - r[0])]; // echo(fn, r, redg, rs, md); // debugging hull() { for (i = [0:7]) { translate((center == false) ? sh : [0, 0, 0]) corner_transl(i, shm) // translate to the eight corners of a cube intersection() { // in any case keep box inside boundaries mirror([(floor(i ) % 2 == 0) ? 0 : 1, // first corner points towards the middle (floor(i/2) % 2 == 0) ? 0 : 1, // in this way all 8 corners are arranged symmetrically 0]) rotate([0, 0, 45]) // rotate in such a way that the first corner union() { // points towards the middle of sphere and optional cylinder sphere(r = rs, $fn = fn); // %sphere(r = redg, $fn = fn); // compare with a high resolution sphere for debugging if ((len(r) >= 2) && (r[1] > 0)) { translate([0, 0, (len(r) >= 3) ? r[2] : 0]) cylinder(h = 2*r[1], r = redg, $fn = fn, center = true); } } corner_transl(i, shlim/2) // translate to the eight corners of a cube cube(shlim, center = true); } } } }