Hi guys,

I'm currently working on one side of a V12 exhaust manifold. I am creating the lofts that will be the pipes coming from the flanges that bolt to the cylinder heads and lead to a junction flange of the six pipes. As I try to create my 2nd loft I get an error popup "Rebuild Errors, The feature could not be completed because it would produce self -intersecting geometry".

Now, it said the same thing for the 1st loft too, but when I tried it a second time it worked (with no changes) finicky SW perhaps?

I've attached 3 .jpg's below that show what I'm trying to achieve. I'm a novice at this, so I'm wondering if perhaps it's something to do with the fact that where my pipes meet on the junction flange plate I have sketched the circles so that the outer diameters of the pipes overlap each other but only by their own thickness, thus leaving an even thickness of material all the way around. I have seen this achieved in other models so I thought it was easily possible (ignorance maybe?)

The 1st and 2nd loft do NOT touch each other at any point other than when they hit the junction flange. Or is it something different altogether that is causing this popup? Maybe my 'over-length' centrelines?

I didn't want to attach the part because when I do the part just gets done for me. I'd rather learn and solve it for myself.........

Dave.