+ bs1 = retain_len + overret_gaplen + 4;
+
+ translate([0,0,0])
+ linear_extrude(height= retain_len)
+ WithRetainSection();
+
+ translate([0,0, bs1])
+ linear_extrude(height= basics_len)
+ BasicSection();
+
+ translate([0,0, bs1+0.1]) mirror([0,0,1]) {
+ intersection_for (sl=[0,1]) {
+ multmatrix([[1,0,0,0],
+ [0,1,sl,0],
+ [0,0,1,0],
+ [0,0,0,1]])
+ linear_extrude(height= overret_gaplen + 10, convexity=100)
+ BasicSection();
+ }
+ }
+