$fn = 32;


width = 20;
hei = 7;
length = 120;
hole = 4.2;
small_hole = 3;
wheel_dia = 40;
wheel_thick = 25;


linkage(hei);

//translate([0,cos(20)*length,0])
//linkage(hei);

translate([width*3,0,25])
plate();

translate([width*3,0,25])
anchor();

translate([width*3,-length,25])
anchor();

translate([width*3,-length,25])
push();

//wheels
//1
translate([-20,0.7*length,-10])
wheel();
//2
translate([-20,-0.7*length,-10])
wheel();
//3
translate([180,0.7*length,-10])
wheel();
//4
translate([180,-0.7*length,-10])
wheel();

translate([-20,73.5,-10])
steering_linkage();

mirror([0,1,0])
translate([-20,73.5,-10])
steering_linkage();

translate([-20,73.5,0.6])
spacer();

//translate([-20,80,0])
//axle();

module axle(){
difference(){
union(){
//axle
rotate([0,90,90])
cylinder(d = 6.4, h = wheel_thick+12, center = true);

translate([0,-18,0])
rotate([0,90,90])
cylinder(d = 9, h = 2, center = true);
}

//through hole for bolting on wheel to axle
rotate([0,90,90])
cylinder(d = 1.4, h = wheel_thick+15, center = true);
}
}


module spacer(){
difference(){
//axle holder - vertical cylinder
translate([0,-17,0])
cylinder(d = 12, h = 5, center = true);

//chasis connector
translate([0,-17,0])
cylinder(d = 3, h = 20, center = true);
}
}

module steering_linkage(){
difference(){
union(){


//axle holder
translate([0,-6,0])
rotate([0,90,90])
cylinder(d = 12, h = 23, center = true);

//axle holder - vertical cylinder
translate([0,-17,0])
cylinder(d = 12, h = 16, center = true);

//linkage
translate([-10,-22,0])
rotate([50,90,90])
cylinder(d = 6, h = 18, center = true);

//linkage
translate([-13,-24.5,0])
rotate([50,90,90])
cylinder(d1 = 10, d2 = 6, h = 5, center = true);

translate([-16.49,-27.42,0])
rotate([50,90,90])
cylinder(d = 10, h = 4.2, center = true);

}
//axle through hole
rotate([0,90,90])
cylinder(d = 6.6, h = wheel_thick+12, center = true);

//chasis connector
translate([0,-17,10])
cylinder(d = 3, h = 20, center = true);

//allowance to push through axle
translate([0,-18,0])
rotate([0,90,90])
cylinder(d = 9.2, h = 10, center = true);

//steering linkage rod hole
translate([-15.5,-26.7,5])
cylinder(d = 3.5, h = 20, center = true);
}
}


module wheel(){
color("gray", 1)
difference(){
rotate([0,90,90])
cylinder(d = wheel_dia, h = wheel_thick, center = true);

translate([0,-15,0])
rotate([0,90,90])
cylinder(d = 0.8*wheel_dia, h = wheel_thick, center = true);

rotate([0,90,90])
cylinder(d = 6.4, h = wheel_thick+4, center = true);
}
}


module push(){


difference(){
union(){

//Arm 1
translate([0.61*width,0.7*length,0])
cube([0.2*width,0.4*length,0.5*width], center = true);

translate([0.51* width,0.9*length,0])
rotate([0,90,0])
cylinder(d = 0.5*width, h = 0.4*width, center = true);

//pivot point 1
translate([0.61*width,0.5*length,0])
rotate([0,90,0])
cylinder(d = 0.5 * width, h = 0.2*width, center = true);

//Arm 2
translate([-0.61*width,0.7*length,0])
cube([0.2*width,0.4*length,0.5*width], center = true);

translate([-0.51* width,0.9*length,0])
rotate([0,90,0])
cylinder(d = 0.5*width, h = 0.4*width, center = true);

//pivot point 1
translate([-0.61*width,0.5*length,0])
rotate([0,90,0])
cylinder(d = 0.5 * width, h = 0.2*width, center = true);

//pivot point bushing
translate([0,0.5*length,0])
rotate([0,90,0])
cylinder(d = 0.5 * width, h = 0.54*width, center = true);
}
//holes
translate([0,0.5*length,0])
rotate([0,90,0])
cylinder(d = hole, h = width + 10, center = true);

//hole for slider
translate([-0.61* width,0.9*length,0])
rotate([0,90,0])
cylinder(d = hole, h = width + 50, center = true);
}
}


module anchor(){
difference(){
union(){
translate([0,0.5*length,0])
rotate([0,90,0])
cylinder(d = hole, h = 0.7*width, center = true);

//pivot point
translate([0,0.5*length,-1])
rotate([0,90,0])
cylinder(d = 0.75 * width, h = width, center = true);

//base
translate([0,0.5*length,-10])
cylinder(d = width, h = hei + 2, center = true);

//stop point base
translate([0,0.44*length,-10])
cube([width,0.4*width, hei+2], center = true);

}

//slot for movement
translate([0,0.5*length,9.5])
cube([0.5*width + 1,width + 4,width + 10], center = true);

//pivot pin through hole
translate([0,0.5*length,0])
rotate([0,90,0])
cylinder(d = hole, h = 2*width, center = true);

//linkage attachment through hole
translate([0,0.5*length,0])
cylinder(d = hole, h = 2*width, center = true);

//linkage attachment through hole counterbore
translate([0,0.5*length,0])
cylinder(d = hole+ 4, h = width, center = true);
}
}


module plate(){


//main body
difference(){
union(){
//linkage
translate([0,9,0])
cube([0.5*width,0.85*length,0.5*width], center = true);


translate([0,0.5*length,0])
rotate([0,90,0])
cylinder(d = 0.5 * width, h = 0.5*width, center = true);

translate([0,-0.5*length+18,0])
rotate([0,90,0])
cylinder(d = 0.5 *width, h = 0.5*width, center = true);

//plate for electronics
translate([0,0,10])
cube([80,length - 10, 5], center = true);
}
//holes
//pivot pin hole
translate([0,0.5*length,0])
rotate([0,90,0])
cylinder(d = hole, h = 0.7*width, center = true);

//plate connector hole
translate([0,0.43*length,0])
cylinder(d = small_hole, h = 2*width, center = true);

//plate connector hole
translate([0,-0.31*length,0])
cylinder(d = small_hole, h = 2*width, center = true);

//slot
hull(){
translate([0,0.37*length,0])
rotate([0,90,0])
cylinder(d = hole, h = 0.7*width, center = true);

translate([0, -0.25 * length ,0])
rotate([0,90,0])
cylinder(d = hole, h = 0.7*width, center = true);
}
}
}



module linkage(hei){
for( n = [0:4]){
translate([n * 40,0,0])
rotate([0,0,-20])
link(hei);
}

for( n = [0:4]){
translate([n * 40,0,hei])
rotate([0,0,20])
link(hei);
}
}


module link(hei){

//main body
difference(){
union(){
cube([width,length,7], center = true);

translate([0, 0.5*length, 0])
cylinder(d = width, h = hei, center = true);

translate([0, -0.5*length, 0])
cylinder(d = width, h = hei, center = true);
}

//holes
translate([0, 0, -1])
cylinder(d = hole, h = hei+3, center = true);

translate([0, length/4, -1])
cylinder(d = small_hole, h = hei+3, center = true);

translate([0, -length/4, -1])
cylinder(d = small_hole, h = hei+3, center = true);

translate([0, -.5*length, -1])
cylinder(d = hole, h = hei+3, center = true);

translate([0, .5*length, -1])
cylinder(d = hole, h = hei+3, center = true);
}
}