I've gotten myself a set of the krusty style power hammer plans and I've been converting the drawings from metric to standard which has been time consuming. Is anyone aware of a simple millimeter to standard fractions, app, chart, or table? Also can anyone recommend the make, model yr or in a perfect world the part number for the leaf spring? My hammer will be a 25lb if that helps, and for safety I will be adding protective cages. I mention that because it seems every time I discuss the power hammer I'm inundated warnings about spring issues and dangers. If anyone has built one I would be interested in how it went for you.