// Penny weights for ball chain // a Parametric re-design of "Weight for swinging pendulum" by Bre (http://www.thingiverse.com/thing:17016) // Using parts of "Parametric Ball Pulley" by zignig (http://www.thingiverse.com/thing:1322) // Designed for use with the polorgraph // Quality of cylinders/spheres $fa = 10; $fs = 0.4; // General options ball_diameter = 5.5; ball_spacing = 69.5/11; // The distance from the centre of one ball to the next link_diameter = 2; roll_diameter = 20.25; roll_height = 0; wall = 6; clip_height = 15; block_height = 25; zip_h= 5; zip_w = 2; // Calculate dimensions PI = 3.1415927; link_length = ball_spacing - ball_diameter ; slotwidth = ball_diameter+2*link_length; module slot(){ union(){ translate ([0, 0, ball_diameter]) sphere (r = ball_diameter/2); rotate([0,90,0]) cylinder(h = wall*4, r = ball_diameter/2, center=true); cylinder(h = ball_diameter, r = ball_diameter/2); translate ([0, 0, ball_diameter/2]) cube([wall*4, link_diameter, ball_diameter], center=true); } } module zip(){ cube([wall*4, zip_w, zip_h], center=true); } translate ([0, 0, wall/2]) rotate([0,90,0]) { difference(){ union(){ translate ([-slotwidth/2, -wall, 0]) cube([slotwidth,2*wall, block_height]); } translate ([0, 0, roll_height+clip_height]) slot(); translate ([0, wall/2, wall]) zip(); translate ([0, -wall/2, wall]) zip(); } }