I didn't change a thing ...
I built one identical to the original poster's, including the pipe cap/carriage bolt arrangement, and it works great. When one of my flying buds saw the pipe cap/bolt arrangement, he did the same.... replacing an inferior approach he had used for the wing connection. He too is delighted with the pipe cap method.![Big grin :D :D](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
I built one identical to the original poster's, including the pipe cap/carriage bolt arrangement, and it works great. When one of my flying buds saw the pipe cap/bolt arrangement, he did the same.... replacing an inferior approach he had used for the wing connection. He too is delighted with the pipe cap method.