I have found that I have to use certain blades in my Martelli. If I put the Olfa blades in it, it wobbles. If I put Fiskar blades--it works fine. Olfa blades have little Mickey Mouse ears around the center hole & the Martelli/Fiskar blades are simply round. I have also managed to crack a blade and it would push the fabric & simply stop before I discovered it was cracked.
I only use Martelli blades in my cutter now. I find they cut better and last longer and they are better for the cutter. It used to "pop" with the Olfa blades in it. Never had a problem with diagonal cuts.
