| 1 | <html> |
| 2 | <head> |
| 3 | <title>Serrated</title> |
| 4 | <script type="text/javascript" src="nt3d.js"></script> |
| 5 | <script type="text/javascript"> |
| 6 | function serrated(length, thickness, depth, serration_count, arc, steps_per_serration, edge_bevel_angle) { |
| 7 | var tau = 2 * Math.PI; |
| 8 | var path_length = serration_count * steps_per_serration; |
| 9 | var path = []; |
| 10 | for (var i = 0; i <= path_length; i++) { |
| 11 | path[i] = [length*i/path_length,0,0]; |
| 12 | } |
| 13 | var serration_length = length / serration_count; |
| 14 | var serration_half_length = serration_length / 2; |
| 15 | var serration_radius = serration_half_length / Math.sin(tau * arc / 2); |
| 16 | var serration_max_height = Math.sqrt(serration_radius*serration_radius - serration_half_length*serration_half_length); |
| 17 | // This emits a Sabre Grind. TODO: Support a double bevel. |
| 18 | // http://en.wikipedia.org/wiki/Grind#Typical_grinds |
| 19 | // http://www.allaboutpocketknives.com/images/aapk_content/blade_bevel.JPG |
| 20 | var edge_height = thickness / (2 * Math.tan(tau * edge_bevel_angle)); |
| 21 | function shape(i) { |
| 22 | var serration_progress = (i % steps_per_serration) / steps_per_serration; |
| 23 | var serration_x = serration_progress * serration_length - serration_half_length; |
| 24 | var serration_height = serration_max_height - Math.sqrt(serration_radius*serration_radius - serration_x*serration_x); |
| 25 | if (arc < 0) serration_height *= -1; |
| 26 | var blade_height = depth + serration_height; |
| 27 | return [[0, 0, 0], |
| 28 | [blade_height - edge_height, 0, 0], |
| 29 | [blade_height, thickness/2, 0], |
| 30 | [blade_height - edge_height, thickness, 0], |
| 31 | [0, thickness, 0]]; |
| 32 | } |
| 33 | return nt3d.extrude(path, shape, [1,0,0], [0,0,1]); |
| 34 | } |
| 35 | var params = [["Blade length", 100], |
| 36 | ["Blade thickness", 2], |
| 37 | ["Blade depth", 10], |
| 38 | ["Number of serrations", 10], |
| 39 | ["Arc of each serration (in turns)", .2], |
| 40 | ["Steps per serration", 11], |
| 41 | ["Edge bevel angle (in turns)", .05]]; |
| 42 | </script> |
| 43 | </head> |
| 44 | <body onload="nt3d.framework(serrated, params)"> |
| 45 | <h1>Serrated</h1> |
| 46 | <p>Make a serrated blade.</p> |
| 47 | </body> |
| 48 | </html> |