I didnt and the knife secured itself in my foot. The knife was lodged in my foot and I had to pull it out.http://ift.tt/29tRgks: Got two stitches. Not too bad. I’m worried more about the hospital bill. Even with company insurance, copay came out to be 500 dollars. I could buy another printer with that money.This is the blade. It went in by about 3/4 of an inch. Going to make a knife holder out of eva foam later like this. http://ift.tt/29o9P8p