I am trying to create a fill pattern that I can use to model grating for various projects.  I have created the cut feature I want to the grating specs and would like to use a fill pattern to fill the entire area, to later be used as a library feature.  When trying to use the square fill pattern at the required spacing, the pattern does not seem to be able to form and creates a polygonal array somehow.  I have attached a picture to explain the problem.  Any help with this matter would be greatly appreciated.