The longerons have to be trimmed in various places … I used a Dremel to carefully remove the notch in the Upper Longeron since it was not possible to do with a hacksaw.
Vans suggest you make some wood blocks to help with twisting the Upper Longerons. I made these first, and they proved useful to help with clamping the longerons to the workbench during deburring etc.
The Lower Longerons also have a long length of material to be removed from both flanges … not easy with the tools I had to hand.
I managed to cut these by carefully running both flanges through my bandsaw at the same time. It worked, but not sure I’d recommend it!
But I didn’t fancy using the Dremel either.
As suggested I tried using a digital level to judge the 10º twist in the Upper Longerons, but I found it hard to be very accurate with it all wobbling about.
So I taped a stick on the end, marked the untwisted position on a piece of board, and drew on a 10º line. This proved an easy way to judge the correct amount of twist.
I was surprised just how much initial twist is required to produce the resting 10º … more than 180º!
Match Drilling Engine Mount Brackets
I reckoned that it would be a top idea to be as accurate as possible when match drilling the Engine Mount Brackets, so I did this job on the drill press. The blocks of wood again came in useful.
Deburring the holes inside the brackets was tricky!
For once an easy job to set the rivets after priming the components, using the squeezer …
… and my Pneumtaic Pop Riveter for the Cherry Rivets.
Note the postion of the curled flange on the Lower Longeron Doubler … I didn’t find this very obvious from the drawings. But checking various other blogs confirmed my understanding.