include <BOSL/constants.scad>;
use <BOSL/metric_screws.scad>;

inner_diameter = 410;
inner_width = 40;
thickness = 4;
inner_curve_diameter = 60;

module wheel( diameter, width, curve_diameter) {
	intersection() {
		linear_extrude( width, center=true)
			circle( d=diameter);
		union() {
			linear_extrude( width, center=true)
				circle( d=diameter-curve_diameter);
			rotate_extrude( angle=360)
				translate( [(diameter-curve_diameter)/2, 0])
					circle( d=curve_diameter);
		}
	}
}

module base() {
	difference() {
		wheel( inner_diameter+2*thickness, inner_width+2*thickness, inner_curve_diameter+2*thickness);
		wheel( inner_diameter, inner_width, inner_curve_diameter);
		translate( [0, 0, inner_width/2])
			linear_extrude( inner_width, center=true)
				circle( d=inner_diameter-15);
	}
	
	*rotate_extrude( angle=360)
		translate( [(diameter-curve_diameter)/2, 0])
			circle( d=curve_diameter);
}

module form() {
	linear_extrude( inner_width+2*thickness+2, center=true)
		offset(50) offset(-100) offset(50)
		polygon([
			[inner_diameter/2+thickness+2, inner_diameter/2],
			[inner_diameter/4, inner_diameter*0.15],
			[-inner_diameter*0.13, inner_diameter*0.13],
			[-inner_diameter*0.1, -inner_diameter*0.4*sin(45)],
			[-inner_diameter*0.45*sin(45), -inner_diameter*0.45*sin(45)],
			[-inner_diameter, -inner_diameter],
			[-inner_diameter, inner_diameter]
		]);
}

scale([1,1,1])
intersection() {
	base();
	form();
}