I have to agree with everyone's commments and please be assured, you are not alone! I can't tell you how many times, I've cut out carefully and measured carefully and haven't had pieces go together "right". I rip and rip and rip if necesary. Rotary cutters, mats and a good omni ruler (that's a brand name-think it's spelled right) do help one to be more accurate. But, please don't quit.......If real frustrated, start another one less complicated......