Hi Rod
In my blog pages for my Duo 480 I reccomended making up a shorter test panel of rudder minus the inside carbon. I used the jig that Rodney gave me from his KD650. The angle is the same. I passed the jig on to David so I assumed he used it also on his Eco 6. Rodney had closed the angle up a tiny bit after his own earlier failures. On my blog you can seee the angle of the jig panel sitting on the table of my drop saw. Further hints were: dont over fill the epoxy in the bottom. Dont screw and glue on the interior batten or coat the insides of the blades with epoxy in advance. Do them wet on wet, which retains the the original flexibility of the plywood . I definately found it helpful to make up a practise piece first. The quality of the plywood these days probably isnt the same, and also the type of ply used may also be important (as again Bernd mentioned)
cheers
Bryan
bryanandmarycox