Love to read all the op's! I know you can do it without special rulers..I do make most of mine with a basic ruler, a protractor and plastic from lids. but I bet after all is said and done I would save money just to buy the ruler and use it instead of all the trial and error. time it takes to do the math etc. (only thing I think I may be saving is my brain) at least the" Alzhiemers experts" say it works
Happy Sewing!