I am looking into creating some super fine sugar (finer than confectioners sugar) for icing. This is more for experimentation than anything, I am more interested to see how this impacts the consistency/texture of the icing than anything. I've tried using a blender and a coffee grinder, starting with both granulated and confectioners sugar, but can't seem to get much finer than the confectioners sugar.
I'm willing to build a device, but I'm not sure the best path forward here. My thoughts were something along the lines of an old stone mill, except in this case I would use food grade steel plates, but that is a big investment.
Is there something existing I can re-purpose for this endeavor or perhaps something relatively low cost I can buy? If not, thoughts on my plan above?