Maybe the "kink" of the blade is common to all rotary cutters??? I seem to have trouble getting a straight cut on a long strip. It's probably just me, but that was another reason I thought I would change from the fiskars to Olfa. So far I haven't had to tighten the screw on the Olfa but my straight cut is only slightly improved.... it's probably just me. Short arms or poor coordination, maybe both. lolol