I’m in the process of process of replacing my old Craftsman jointer. One of the questions I have is: is a spiral head worth the extra cost? Could you please give me a brief summary of the advantages of the spiral head over a conventional three-knife head? - Tom Libby
Tim Inman: For me, the cost of a spiral head cutter is not worth the money on a small jointer. The spiral enables the cutting to be done on a shear angle, and makes a nicer, smoother cut on tough woods. I do have a spiral cutterhead on my planer. For most of my jointer needs, which do not involve surfacing big boards, the old fashioned cutter knives work just fine. In fact, it is easier to keep them razor-sharp - which is the really important element in a cutterhead, straight or spiral!
Chris Marshall: I'll take the counterpoint to Tim here. Both my jointer and planer have spiral cutterheads, and I'm a big fan of them. The little carbide insert cutters don't require sharpening, and they retain a sharp edge for a long while. When they get knicked or start to dull, just loosen a screw, give them a quarter turn, and you'll have a fresh, sharp edge. You'll also never need to fuss with the typical straight-knife sharpening issues: finding top dead center, aligning your jointer knives uniformly in relation to one another and tightening gib screws without shifting the knife settings in the process. So, speaking from the standpoint of maintenance simplicity, I think helical cutterheads are a dream. Then, there's the benefit of the shear cutting angle they provide. When I'm building a project with wood that is likely to tear out during surfacing, such as figured maple, I don't have to worry. My jointer tames that tricky grain without issues. For me, the added expense of a helical cutterhead is definitely worth it in the long run.