Popular Woodworking 2007-06 № 162, страница 51

Popular Woodworking 2007-06 № 162, страница 51

The assembled chipbreaker and iron. When the plane's iron cuts a shaving, it immediately is deflected up and kinked by the chipbreaker. The shaving is ejected out of the plane.

The lateral adjustment lever keeps the cutting edge parallel with the sole. When you move it all the way left (from the operator's perspective), the right corner of the iron tips into the work. When you move the lever left, the opposite effect occurs.

control, and the resulting surface would be quite rough.

That is where the sole of the plane comes in. The flat sole ahead of the cutting edge holds the wood down and prevents it from being torn loose by a levering action. Because it cannot lift the chip ahead of it, the cutter shears a continuous shaving. That shaving then passes up through the mouth and is ejected from the plane.

advent of the chipbreaker

For millennia, the sole of the plane was the only prevention against tearing. In the 18th century, plane makers developed the chipbreaker. The chipbreaker

looks like a second blade that is secured to the cutter by a stubby screw with a wide, flat head. Adding a chipbreaker gave rise to the terms a "double," or a "capped iron." The chipbreaker itself has a bow in its end. When the breaker and the cutter are assembled and the screw is tightened, the cutter is stiffened. This stiffening helps the cutter to resist chattering due to the force of cutting, and results in a cleaner surface.

The addition of the chip-breaker resulted in a change in the plane irons. They now had a slot along much of their length. The slot had a round end to allow the screw head to pass through.

The chipbreaker's name describes its most important function: As the chip rises up through the mouth it immediately encounters the convex curve at the end of the chipbreaker. Instead of rising up in a line along the surface of the cutter, which helps create a levering action, the chip is bent forward, causing it to kink. Now broken at each kink, the chip is much less likely to be lifted by levering. These kinks occur at very short, regular intervals measuring many per inch. As a result, a broken chip tends to roll up into a tube as it leaves the mouth.

The Frog

In wooden planes a double iron, like the earlier single iron, was still secured by a wooden wedge. However, Bailey attached the cutter and chipbreaker assembly to the frog's 45° bed with a device called a lever cap. The lever cap has a locking lever at the upper end. There is a cam on the hinged, lower end of the lever. Thus, the cap can be tightened and loosened very quickly by lifting or lowering the lever. A roundhead machine screw secures the cutter/chip-breaker assembly and lever cap tightly to the frog. Stanley and other makers found the cap's visible front surface a nice place to display the company's name.

The frog itself has two important adj ustments - the lateral and longitudinal. When using a plane one wants the cutting edge to be

parallel to the sole. If it is not, it will cut more deeply on one side than on the other and leave an unsightly track on the wood's surface. It is important for a plane to also be able to control the chip's thickness. On a wooden plane both blade adjustments were accomplished by tapping the tool with a light hammer. On a Bailey plane they are controlled by adjustments in the frog.

Lateral adjustment

Lateral adjustment, that which allows the cutting edge to be set parallel to the sole, is accomplished by a lever under the cutter. This lever extends between the cutter and the tote, to provide easy access. The lever is secured to the frog with a rivet that allows it to pivot. On the end of the lever is a wheel that fits into the slot in the cutter. On later planes the wheel was eliminated and the end of the lever became merely a bent lip. By moving the lateral adjustment lever side to side, the cutter/ chipbreaker assembly will pivot under the lever cap. If you push the lever to the right, it extends the left side of the cutting edge, and vice versa.

longitudinal adjustment

Behind the frog is a brass wheel (on later planes this can be made of other, less expensive materials). This wheel regulates the cutter's longitudinal adjustments. The wheel is mounted on a stud with

The brass wheel behind the frog regulates the depth of cut. Rotate the wheel clockwise to increase the cut and counterclockwise to decrease it.

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