I built a jig to help me assemble the flaps and ailerons of my BD-4C. Note the use of aviation-grade aluminum gutter flashing to face the jig, obtained from the aviation aisle at the local hardware store.
Here is a shot with a flap skin and three ribs set into the jig.
[…] I insert the flap skin into the jig that I made and press it down with the three wooden ribs. It looks something like this (though this photo was […]