Hi Peter, yup that is an extremely complicated piece from the perspective of the boolean union code. It has to try and intersect all those pieces with one another and sort out all the results. A large number of edges and pieces running over top of each other makes that job a lot more difficult.

For something like what you show there, I would recommend working more with 2D curves - perform your array just on 2D curves, then use booleans or manual trimming to get the 2D outlines all finished up, and extrude it to a solid all in one extrude command.

That would be a more robust method for arriving at the final result in this case, rather than trying to make the booleans try to resolve so many intersecting 3D pieces.

- Michael