Is this jig similar to the Great Planes wing jig ?
Not really. This jig is made with 1 x 1 1/2 inch aluminum tubing with 1/2 inch conduit mounted on top of the alu. U channel wood holds the 2 pieces of alu. The pieces that support the ribs fit onto the conduit and can slide for proper position. The unit can be adjusted in the middle to provide built-in dihedral. A jig is provided to drill holes in the ribs at the correct spacing. It takes a bit to set-up but when ready is really easy to work with.
Tom...