JohnReid
A Fixture
The black fittings you see here are made from brass and then blackened.A better choice would have been aluminum painted black, as it is a whole lot easier to work with when designing the fittings ,especially when shaping and drilling when they are already attached to the tail booms.
Here I am checking that the vertical struts will be at right angles when level.
Here I am checking that the vertical struts will be at right angles when level.