Hello all,

So basically I need to model out a small airplane framing, which consists of tubing that has many variations in od's and wall diameters depending on location in the airplane.  My issue is first off, how can you combine multiple sized weldments.  Example, three lines from each axis meet at the origin (just as the triad looks), and having each line be a different size weldment.  And from there, have them combine at that point correctly and not look completely wrong.  I was able to get the different sized weldments by using a different structural member for each.  But they look completely wrong when I combine them at that center point.  Two of them look right, but when you add a third, nope. 

Now for the angles.  Of course there is not just 90 degree angles everywhere (would be nice huh?).  There is all sorts of angles combining to other pipes,  I have no idea how exactly I can achieve this.  I guess combining multiple 2d and 3d sketches.

Any help is greatly appreciated.

Thanks!

Chris