tread_link|maurer.gg

Sandbox tread_link

$fn=100;

link_l=24;
link_w=48;
link_d=8;
tooth_hole_l=link_l/4;
tooth_hole_w=link_w/4;

pin_diameter=4;
thread_diameter=2.6;

tpl=5;
tread_w=1.75;
tread_d=1;

link_w_inset=link_w/4;
link_l_inset=link_d;

link_d_inset=link_d+tread_d;
tread_gap= (link_l-link_d)/tpl;

module link_base(){
    hull(){
        circle(r=link_d/2);
        translate([link_l-link_d,0,0])
        circle(r=link_d/2);
    }
}

module chevron(s,l, a){
    union(){
        rotate([-(90-(a/2)),0,0])
        translate([0,-s/2,-l/2])
        cube([s,s,l],center=true);
        rotate([90-(a/2),0,0])
        translate([0,-s/2,l/2])
        cube([s,s,l],center=true);
    }
}
treads(4);
module treads(n){
    tread_link();
    for(i=[1:1:(n-1)]){
    translate([(-link_l+link_d)*i,0,0])
    tread_link();
    translate([(-link_l+link_d)*(i-1),0,0])
    pin();
    }
}

module master_pin(){

}

module pin(){
    union(){
        cylinder(h=link_w,r=pin_diameter/2);
        union(){
            cylinder(h=(link_w_inset/4)-0.2,r=(pin_diameter/2)*1.5);
            translate([-pin_diameter*0.75,-link_d/2,0])
            cube([pin_diameter*1.5,link_d/2,(link_w_inset/4)-0.2]);
        }
        translate([0,0,(link_w-(link_w_inset/4))+0.2])
        union(){
            cylinder(h=(link_w_inset/4)-0.2,r=(pin_diameter/2)*1.5);
            translate([-pin_diameter*0.75,-link_d/2,0])
            cube([pin_diameter*1.5,link_d/2,(link_w_inset/4)-0.2]);
        }
    }
}

module tread_pattern(){
    union(){
            translate([0,link_w/2,-.6])
            rotate([-90,0,0])
            chevron(1,link_l,135);
            translate([0,link_w/2,5])
            rotate([-90,0,0])
            chevron(1,link_l/1.1,135);
     }
}

module tread_link(){
    difference(){
        union(){
            linear_extrude(link_w)
            link_base();
            rotate([90,0,90])
            translate([(link_d/2)+0.5,0,0])
            tread_pattern();
        }
        union(){
            translate([-link_d/2,-link_d/2-tread_d,-1])
            cube([link_l_inset+0.2,link_d_inset,link_w_inset+1.2]);
            translate([-link_d/2,-link_d/2-tread_d,link_w-link_w_inset-0.2])
            cube([link_l_inset+0.2,link_d_inset,link_w_inset+1]);
            translate([0,0,link_w_inset])
            cylinder(h=link_w/2, r=(pin_diameter+0.4)/2);
        }
        union(){
            translate([link_l-link_d/2-link_l_inset-0.2,-link_d/2-tread_d,link_w/2-(link_w_inset)])
            cube([link_l_inset+1,link_d_inset,2*(link_w_inset)]);
            
            translate([link_l-link_d,0,-1])
            cylinder(h=1+(link_w)/2, r=(pin_diameter+0.4)/2);
            
            translate([link_l-link_d,0,link_w/2])
            cylinder(h=(link_w-link_w_inset/2), r=(pin_diameter+0.4)/2);
        }
        translate([tooth_hole_l/2,-link_d/2-tread_d-link_d_inset/2,link_w/2-tooth_hole_w/2])
        cube([tooth_hole_l,link_d_inset*2,tooth_hole_w]);
        translate([link_d+link_d/2,-link_d/2,0])
        cube([link_d,link_d,link_w_inset/4]);
        translate([link_d+link_d/2,-link_d/2,link_w-(link_w_inset/4)])
        cube([link_d,link_d,link_w_inset/4]);
        
        
    }
}