Hi George, thanks for posting this problem file.

Currently you can work around the problem by picking your array origin point in the Top view rather than in the 3D view.

The problem you are running into here is that there is an automatic construction plane alignment to planar objects for certain commands when you pick a point in the 3D view.

That's to support doing things like drawing a rectangle on the side of a box in the 3D view without having to set your construction plane up as an extra step.

Similarly the idea was to allow it for array circular to allow things like the following, where picking the array origin point on a plane uses that plane for the array orientation:




In your case here, when you pick the point on the corner of the solid there, there are several planes in the solid there it will try to align to, and it will pick the one that is pointing most towards you, which will be one of the shorter vertical ones rather than the top one.


Anyway, that's the reason for the strange result. If you angle your 3D view to be more looking downwards (so the top plane is the one more pointing towards you than the side pieces)or switch to the Top view you should get the result you expected.

I'll probably need to turn off automatic snap plane alignment for array circular though so that this does not happen. You'll still be able to get a result on any plane by setting up a construction plane first before doing the array though.

- Michael