/* Pinion chain protection */

/* Gates rim parameter */
DiameterFront=152;              /* mm */
DiameterBack=109;               /* mm */
CenterDistanceFrontBack=475;    /* mm */
GateRimWidth=13;                /* mm */
rimSpace=3;                     /* mm */

/* Pinon parameter */
pinionTop=106;      /* mm */
pinionBottom=38;    /* mm */
pinonHeight=98;     /* mm */
pinionRotation=45;  /* degrees */
pinionWith=50;      /* mm (dummy value, not used) */
$fn=180;

/* Bike Parameter */
bikeRearHorizontal=48;
bikeRearRotation=99;
bikeRearOffset=70;

module drawRim(dBack, dFront, width) {
    hull() {
        translate([CenterDistanceFrontBack/2, 0, 0]) cylinder(d=dFront, h = width, center = true);
        translate([-CenterDistanceFrontBack/2, 0, 0]) cylinder(d=dBack, h = width, center = true);
    }
}

difference() {
    drawRim(dBack=DiameterBack+rimSpace*2, 
            dFront=DiameterFront+rimSpace*2,
            width=GateRimWidth+rimSpace*2);
    union() {
        translate([0,0, rimSpace/2]) drawRim(dBack=DiameterBack, 
            dFront=DiameterFront,
            width=GateRimWidth+rimSpace*2);
        translate([CenterDistanceFrontBack/2, 0, 0]) rotate([0, 0, pinionRotation])    translate([pinionBottom, 0, 0]) cube([pinionTop+pinionBottom, pinonHeight, pinionWith], center=true);
    translate([bikeRearOffset, 0, 0]) rotate([0, bikeRearRotation, 0]) cylinder(d=bikeRearHorizontal, h=CenterDistanceFrontBack, center=true);
        
    }
}