6 houterrad = hinnerrad + hoopthick;
10 blockwidth = hcentredist*2 + 6;
12 module Oval(centredist, rad) {
14 translate([-centredist/2,0,0]) circle(r=rad);
15 translate([+centredist/2,0,0]) circle(r=rad);
21 Oval(hcentredist, houterrad);
22 Oval(hcentredist, hinnerrad);
28 translate([0, (blockdepth + hoopthick)/2 + hinnerrad])
30 blockdepth + hoopthick],