The frame on my re-build project does not match any official drawings. It is the same as the current drawings until aft of the cockpit.. It was flying with iO 360, but I am putting a 540. After talking to Paul at Steen, he recommended I upgrade the rear structure to the current standard. The blue tape in the photo shows the way it should be.
A. I can cut out the entire section and start over.
B. I can cut out tubing that interferes with the new sections. There is no way to remove tubing from a cluster weld without significantly weakening it so I would leave I inch or so and cap it-weird looking but easy.
C. Leave all the existing tubing in place and weld new sections into it. This would leave all the existing tabs and stand offs in place. It would add weight, but my understanding is most 540 installations need weight in the tail. It does run the risk of making it too stiff, transferring loads to where they shouldn't be rather than allowing it to flex over the same distance.
These are just random thoughts at this point, I have not talked to my tech adviser as yet.
Feel free to criticize or advise, I want to find the smoothest way over this hurdle. As I have written this, I think it will wind up being A. Tried, and tested. I don't like experimenting with primary structure.
Robin
A. I can cut out the entire section and start over.
B. I can cut out tubing that interferes with the new sections. There is no way to remove tubing from a cluster weld without significantly weakening it so I would leave I inch or so and cap it-weird looking but easy.
C. Leave all the existing tubing in place and weld new sections into it. This would leave all the existing tabs and stand offs in place. It would add weight, but my understanding is most 540 installations need weight in the tail. It does run the risk of making it too stiff, transferring loads to where they shouldn't be rather than allowing it to flex over the same distance.
These are just random thoughts at this point, I have not talked to my tech adviser as yet.
Feel free to criticize or advise, I want to find the smoothest way over this hurdle. As I have written this, I think it will wind up being A. Tried, and tested. I don't like experimenting with primary structure.
Robin
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