db25: add maximum dimensions of connector shell

db25.scad

@@ -43,6 +43,10 @@ E = 12.93;
 // depth of contacts
 c_depth = 9.5;
 
+// max size of shell
+shell_l = 55.0;
+shell_w = 8.2 * 2;
+
 ang = 10;
 d_s = 3.4 / 2;