Re. rotary cutters. Are you sure it is the blade at fault,if they only last for one cut. What sort of cutting mat do you use? Even if you are bad at cutting they should last longer than one cut, that would only affect the measurement of your cut, not the sharpness of your blade. Perhaps someone is using your cutter for something other than fabric, paper or card maybe----- there are such unknown fairies around ( you know who you are !!) However, hope you can solve your problem . Love