Combines the advantages of Shear & Helix and Spiral tooth action
Woodworkers know that a shear cut is far better than a straight cut. They also know that a staggered knife arrangement is much better than just a single straight knife and is a lot easier on your collection system. If it happens that you hit a nail or staple, it is not necessary to replace expensive knives the full length of your cutterhead. Replace 2 or 3 small inexpensive knives and you are ready to go.
Typically, a small shop where the planer is only used 8- 10 hrs per week will operate with no knife changes for up to a year. In some shops where the SHELIX® is used constantly, the operator might need to rotate the knives every 1 - 2 months, depending on the species and cleanliness of the wood. Realizing that carbide can last for a very long time, many factories will only replace a single damaged knife that is causing an undesirable finish on the workpiece. This might be done once every 3-5 days. Many times this is the ONLY thing that is done for replacement. Many never change the entire set of blades. This is possible because the shear action in the cut will make a clean cut even if the knives are dull when compared to a normal straight knife application.
The SHELIX® cutterhead is a precision made tool. Close tolerances are held in order to achieve a good finish on the wood. It is absolutely imperative that the screw be taken completely out, the knife to be assembled is clean, and the seat where the knife is to be installed is clean. Just think about it, if there is .005” of wood dust or pitch underneath the installed knife, then the board will have a noticeable .005” groove!
SPIRAL STAGGER TOOTH to break up chips for dust collection efficiency
SHEAR to give clean cutting action
HELIX to assist the chip flow