front_slope = 1.0;
front_th = 2;
-gap_th = 9.5 + 0.5;
-back_th = 4;
+gap_th = 6.5 + 0.5;
-back_tot_l = 32.5;
-back_cut_l = 4;
-back_cut_w = 13;
+back_tot_l = 35.5;
+back_cut_l = 6;
+back_cut_w = 15.0 + 1.0;
back_prong_w = 3;
back_hole_d = 2;
-back_hole_dia = 1 + 0.5;
+back_hole_dia = 1 + 1.5;
+
+back_th = back_hole_dia + 2.4;
module MidPlan(){
polygon([[0, 0],