straightens out any warp a piece may have; a piece that goes into the surfacer warped will come out still warped. This is not a defect in the machine; the surfacer is designed for surfacing only, not for truing warped stock. If true plane surfaces are desired, one face of the stock (the face that goes down in the surfacer) must be trued on the jointer before the piece is feed through the surfacer. If the face that goes down in the surfacer is true, the surfacer will plane the other face true.

Observe the following safety precautions when operating a surfacer:

The cutting head should be covered by metal guards.

Feed rolls should be guarded by a hood or a semicylindrical guard.

Never force wood through the machine.

If a piece of wood gets stuck, turn off the surfacer and lower the feed bed.

Figure 3-12. - Three-wing cutter for a shaper.

Shaper

The shaper is designed primarily for edging curved stock and for cutting ornamental edges, as on moldings. It can also be used for rabbeting, grooving, fluting, and beading.

The flat cutter on a shaper is mounted on a vertical spindle and held in place by a hexagonal spindle nut. A grooved collar is placed below and above the cutter to receive the edges of the knives. Ball bearing collars are available for use as guides on irregular work where the fence is not used. The part of the edge that is to remain uncut runs against a ball bearing collar underneath the cutter, as shown in the bottom view of figure 3-12. A three-wing cutter (top view of figure 3-12) fits over the spindle. Cutters come with cutting edges in a great variety of shapes.

For shaping the side edges on a rectangular piece, a light-duty shaper has an adjustable fence, like the one shown on the shaper in figure 3-13. For shaping the end edges on a rectangular piece, a machine of this type has a sliding fence similar to the cutoff gauge on a circular saw. The sliding fence slides in the groove shown in the table top.

On larger machines, the fence consists of a board straightedge, clamped to the table with a hand screw,

Figure 3-13. - Light-duty shaper with adjustable fence.