Powermatic PM15 operating instructions Introduction to Molding, Planing for Finish, Pattern Knives

3.Stand to one side of the machine and start the board under the infeed roller so that it travels in a straight line. As the infeed roller takes hold, let go and remain standing to one side of the unit – never directly in line with the board. The power feed will complete the travel without further pushing or pulling.

Planing for Finish

Planing for a smooth finish is best accomplished by taking light cuts on the board. However, several other things are important to achieve a smooth finish.

Always feed board in a direction that allows the planer blades to cut with the grain as shown in Figure 24. This aids the knife in severing the wood fibers rather than lifting and tearing the fibers. Torn fibers give a fuzzy appearance to the surface. Feeding against the grain can also cause your knife to lift large chips from the board’s surface, causing a very unsightly appearance.

Introduction to Molding

Pattern Knives

Custom molding knives are ground from high speed hard steel. Your PM15 planer-molder will accept a single knife set, which uses gibs and counterbalances to ensure the cutterhead is in balance at all times. See Figure 25. It will also accept a three-knife set.

The three-knife molding set allows the planing knives to remain within the cutterhead, as long as the pattern knife is no more than 1/8” thick and no wider than 3”.

Optional Bedboard and Guide

The use of a bedboard is highly recommended and can be extremely critical in cases such as custom pattern knives and molding bits where they are designed to cut below the molding to eliminate rough edges and to final size the molding. In this case, the use of a bedboard is mandatory in keeping the tips of the custom pattern knives away from the cast planer bed.

Always use a bedboard with a custom pattern knife, or damage to the knives, planer bed and cutterhead can result.

Figure 24

Figure 25

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