After about a year witrh the raptor type drive gear I was starting to throw tools and cuss a lot. Then I ordered a mk7 style gear and immediately I was at peace and my printer was working 10 times better. It really was a night and day difference. The extruder I own came with a raptor gear so I figured it would at least work pretty well. Then I suspected it was causing many issues and had my friend fashion a gear up on his lathe that I cut teeth with a rotory tool. It was ok, but then I finally ordered a " commercial " MK7 style gear. What a difference.