catch_strap_width = sm_main_width;
catch_strap_thick = sm_main_thick;
catch_stem_end_h = catch_stem_h;
-catch_pin_width = rivet_entry_width - catch_pin_gap;
+catch_pin_width = (rivet_entry_width * bayo_real_rad / bayo_nom_rad)
+ - catch_pin_gap;
+
+echo("R ", sm_inner_rad, bayo_real_rad, bayo_nom_rad);
cppy6 = -catch_strap_width/2;
cppxC = 0.34 * sm_inner_rad * TAU;