Just putting this out there, May be of use to someone that wants to use spiral blades. This is a video by Charles Dearing. He is what started me on spirals many years ago... He ha s great pattern designer. His site is Woodenvisions.com. Keep in mind, Charles has never used a straight blade. Most the pictures he scrolled were big, I mean in the 3 ft., by 4 ft. range. He has always use a #5 spiral blade. He video helped me get started with spiral, although I do it quite differently than him and I mostly is a 3/0 sized spiral when I use them.. But this is a good video to get started, them experiment and find out what works best for you.