// #######################################################
// ######################## Idler ########################
// #######################################################

// 624 bearing: 13x4x5
bearing_outer = 13;
bearing_inner = 4;
bearing_height = 5;

idler_outer_height = 7;
idler_dia = 15;
idler_ramp_dia = 16;
belt_height = 6;
dia_off = 0.1;
ramp_step_size = 0.05;

idler_dist = 0.1;
spacer_size_add = 2;

bearing_height_diff = belt_height - bearing_height;
idler_ramp_add = (idler_outer_height - belt_height) / 2;

spacer_height = idler_outer_height - bearing_height + idler_dist;

bearing_spacer_height = (spacer_height - (idler_outer_height - bearing_height) / 2) * 2 + (idler_outer_height) * 2 + idler_dist;

module bearing_624() {
    $fn = 15;
    difference() {
        cylinder(d = bearing_outer, h = bearing_height);
        translate([0, 0, -1])
            cylinder(d = 4, h = bearing_height + 2);
        translate([0, 0, bearing_height - 0.5])
        difference() {
            cylinder(d = bearing_outer - 2, h = 2);
            cylinder(d = bearing_inner + 2, h = 2);
        }
        translate([0, 0, -1.5])
        difference() {
            cylinder(d = bearing_outer - 2, h = 2);
            cylinder(d = bearing_inner + 2, h = 2);
        }
    }
}

module bearing_idler() {
    $fn = 30;
    
    translate([0, 0, idler_ramp_add]) {
        %translate([0, 0, bearing_height_diff / 2])
            bearing_624();
        
        color("yellow")
        difference() {
            cylinder(d = idler_dia, h = belt_height);
            translate([0, 0, -1])
                cylinder(d = bearing_outer + dia_off, h = belt_height + 2);
        }
        
        color("yellow")
        for (i = [ramp_step_size : ramp_step_size : idler_ramp_add]) {
            difference() {
                union() {
                    translate([0, 0, belt_height + i - ramp_step_size])
                        cylinder(d = idler_dia + (i * 4 * (idler_ramp_dia - idler_dia)), h = ramp_step_size);
                    translate([0, 0, ramp_step_size - i])
                        cylinder(d = idler_dia + (i * 2), h = ramp_step_size);
                }
                translate([0, 0, -1])
                    cylinder(d = bearing_outer + dia_off, h = belt_height + 2);
            }
        }
    }
}

module bearing_spacer() {
    $fn = 30;
    difference() {
        cylinder(d = bearing_inner + spacer_size_add, h = spacer_height);
        translate([0, 0, -1])
            cylinder(d = bearing_inner + dia_off, h = spacer_height + 2);
    }
}

module bearing_spacer_assembly(only_outer, top) {
    translate([0, 0, spacer_height - (idler_outer_height - bearing_height) / 2]) {
        if ((!only_outer) || top) {
            color("magenta")
            translate([0, 0, -spacer_height + (idler_outer_height - bearing_height) / 2])
                bearing_spacer();
        }
        
        if (!only_outer) {
            bearing_idler();

            color("magenta")
            translate([0, 0, idler_outer_height - (idler_outer_height - bearing_height) / 2])
                bearing_spacer();

            translate([0, 0, (2 * idler_outer_height) + idler_dist])
                rotate([0, 180, 0])
                bearing_idler();
        }
        
        if ((!only_outer) || (!top)) {
            color("magenta")
            translate([0, 0, (2 * idler_outer_height) + idler_dist - (idler_outer_height - bearing_height) / 2])
                bearing_spacer();
        }
    }
    
    echo(bearings_spacers_height=bearing_spacer_height);
}

bearing_mount_wall = 8;
bearing_mount_width = 15;

idler_distance = 3;
idler_off_z = 0.5;

module slot_mount_bracket(slot, preview) {
    $fn = 15;
    
    color("green")
    translate([0, 0, slot])
    difference() {
        cube([slot, bearing_mount_width, bearing_mount_wall]);
        
        translate([slot / 2, bearing_mount_width / 2, -1])
            cylinder(d = 4.2, h = bearing_mount_wall + 2);
    }
    
    color("green")
    translate([slot, 0, 0])
    difference() {
        cube([bearing_mount_wall, bearing_mount_width, slot + bearing_mount_wall]);
        
        translate([-1, bearing_mount_width / 2, slot / 2])
            rotate([0, 90, 0])
            cylinder(d = 4.2, h = bearing_mount_wall + 2);
    }
    
    difference() {
        bearing_appendage(slot, preview);
        
        translate([slot + bearing_mount_wall + idler_ramp_dia / 2 + idler_distance, bearing_mount_width / 2, -5])
            cylinder(d = 4.2, h = slot + (2 * bearing_mount_wall) + 2);
    }
}

module bearing_appendage(slot, preview) {
    color("green")
    translate([slot + bearing_mount_wall, 0, slot])
    hull() {
        cube([1, bearing_mount_width, bearing_mount_wall]);
        
        translate([idler_ramp_dia / 2 + idler_distance, bearing_mount_width / 2, 0])
            cylinder(d = bearing_inner + spacer_size_add, h = bearing_mount_wall);
    }
    
    translate([slot + bearing_mount_wall + idler_ramp_dia / 2 + idler_distance, bearing_mount_width / 2, slot - bearing_spacer_height + idler_off_z]) {
        bearing_spacer_assembly(true, false);
        bearing_spacer_assembly(true, true);
        
        if (preview) {
            bearing_spacer_assembly(false);
        }
    }
    
    color("green")
    translate([slot + bearing_mount_wall, 0, 0]) {
        hull() {
            cube([1, bearing_mount_width, bearing_mount_wall]);
            
            translate([idler_ramp_dia / 2 + idler_distance, bearing_mount_width / 2, 0])
                cylinder(d = bearing_inner + spacer_size_add, h = bearing_mount_wall);
        }
        translate([idler_ramp_dia / 2 + idler_distance, bearing_mount_width / 2, bearing_mount_wall])
            cylinder(d = bearing_inner + spacer_size_add, h = 7);
    }
}

//slot_mount_bracket(30, true);