Granny Square blocking square

I received a similar square as a free bonus with a magazine I bought, but the posts that the granny square sits on were removable which resulted in them coming out if you picked it up. My husband came up with the idea of making it with my 3d printer, but doing it so that the posts are incorporated in the base part. This is the resulting print from that idea.
Since I have taken this picture I have revised the base part and it isn't as high but the posts are still the same height, will add a picture when it finishes to print.
The STL file that I have included is of the smaller base.