I bought that rotary blade cutter some time back from the Grace Co. It does not and has never made any blade that I've tried sharpen..sharp. In fact, it makes it worse than it was to start with...just watched that Youtube video of someone demonstrating the sharpener. The directions that came with my sharpener did not say anything close to the number of runs on the youtube. So I decided I'd give it one last try before pitching a very pricey no good product. Used it on two cutters..it made both of them much much less sharp, in fact, it rendered them unusable. I suppose I could have gotten a lemon but I suspect it just is useless.
Anna