I have Tom Morris' "Lincoln Log" jig, an Adjust-O-Jig, and a 95th Aero Squadron jig (which I haven't yet used), but it's is very similar to the one CLC sells . Almost any jig is superior to "no-jig", and almost any will work well if you practice with it. None are automatic; each requires a slightly different procedure. It is possible to build a poor wing even with a jig, if the jig is not set up and used properly.