OPERATION
PILOT BIT EDGING
See Figure 17.
Rabbets and molded edges can be cut using piloted cutters. The pilot extends below the cutter. Some pilots are solid extensions of the cutter. Others are ball bearing guides that are fastened to the end of the cutter. The pilots allow the cutters to turn while the pilot follows the edge of the workpiece.
Whenever the workpiece thickness together with the desired depth of cut (as adjusted by router depth setting) are such that only the top part of the edge is to be shaped (leaving at least a 1/16 inch (1.6 mm) thick uncut portion at bottom), the pilot can ride against the uncut portion, which will serve to guide it. See Figure 17. However, if the workpiece is too thin or the bit set too low so that there will be no uncut edge to ride the pilot against, an extra board to act as a guide must be placed under the workpiece. This “guide” board must have exactly the same contour — straight or curve — as the workpiece edge. If it is positioned so that its edge is flush with the workpiece edge, the bit will make a full cut (in as far as the bit radius). On the other hand, if the guide is positioned as shown in Figure 17 (out from the workpiece edge), the bit will make less than a full cut — which will alter the shape of the finished edge. NOTE: When edge shaping with guides, any of the piloted bits can be used without a pilot. Also, the size (diameter) of the pilot that is used determines the maximum cut width that can be made with the pilot against the workpiece edge (the small pilot exposes all of the bit; the large one reduces this amount by 1/16 inch (1.6 mm).
When routing all the edges of a panel or board, rout the end grain first. Any splintering that occurs at the corners will then be removed when routing the edge. Start each side 1/4 in. (6.35 mm) away from the end. Feed the cutter into the wood until the pilot contacts the uncut edge. Then, slowly back the router to shape the corner. Next, move the router forward to shape the rest of the edge. Be careful to keep the pilot pressed against the uncut edge. Repeat this procedure on each side of the panel. Figure 18 shows the proper sequence of cuts to make when edge routing four sides of a panel.
ROUTER
PILOT
WORK
TOP EDGE SHAPING
ROUTER
WORK
PILOT
GUIDE
| WHOLE EDGE SHAPING | Fig. 17 |
|
| |
| 6 | 5 |
3 |
|
|
4 | PROPER CUTTING SEQUENCE | 2 |
|
| |
|
| 1 |
7 | 8 |
|
| 1/4 in. to 1 in. |
|
| (6.35 mm to 25.4 mm) | Fig. 18 |
17