+$fa = 1;
+
+module HalfBaseline() {
+ intersection(){
+ translate(C + [0, jaw/2])
+ circle(r=r);
+ rectfromto([ -width/2, -1, ],
+ [ width/2, jaw ]);
+ }
+}
+
+module Baseline(){
+ HalfBaseline();
+ mirror([0,1]) HalfBaseline();
+}
+
+module Plan(){
+ difference(){
+ offset(delta=th) Baseline();
+ Baseline();
+ rectfromto([-width, -jaw/2],
+ [0, jaw/2]);
+ }
+}
+
+module Thing(){
+ linextr(0,l) Plan();