+module BaseRegistrationProtrusion(extra){
+ size = protrusion_size + extra;
+ translate([0, base_backfront/2, 0]){
+ hull(){
+ translate([0,0, -0.5])
+ cube([protrusion_size*2, protrusion_frontback, 1.0], center=true);
+ translate([0, 0, protrusion_size-0.5])
+ cube([0.05, protrusion_frontback-protrusion_size*2, 1.0], center=true);
+ }
+ }
+}
+