|CHAPTER 3, LESSON 2 of 3
GOAL: To understand the systems available for guiding a handheld router over a stationary workpiece.
There are seven systems for guiding a router as its bit cuts a workpiece. Four are applicable when the router is handheld and passed over the top of a workpiece clamped to a table or bench; three involve pushing the workpiece past the cutter with the router mounted under a table. This lesson will explain the four guide systems for cutting with a handheld router.
In using each of the following router guide systems, you must control the travel of the router. It must be held firmly so that contact between fence and guide is constant, and the workpiece must be securely fixed.
Guide System 1: Fence Attached to Workpiece
|Using two fences, you can quickly and accurately make a dado to nearly any width you want.
The fence is the wood or metal straightedge clamped to the workpiece. The guide is the edge of the router base. The offset is the distance from the guide to the bit’s cutting circle. This is the simplest guide system. With it you can:
1. Square the edge of the workpiece by taking a full cut with a straight bit.
2. Make a rabbet with a straight bit.
3. Mold all or part of the edge with a curved or complex bit.
4. Make a groove along the face of the workpiece. A fixed-base router can only make a through groove, while a plunge router can make a stopped groove.
5. Make a dado or housing across the face of the workpiece. A fixed-base router makes a through housing, while a plunge router can make a housing that stops short of the edge of the wood.
6. Make a mortise using a straight bit, a plunge router and a simple jig.
Guide System 2: Guide Attached to Router Base
The base guide attached to the router base steers the router along the edge of the workpiece. The fence is the edge of the workpiece. The offset is the distance from the guide to the bit’s cutting circle. With this guide system you can:
1. Mold part of a square edge, though not the whole edge because part of it must remain intact to act as the fence.
2. Run grooves, flutes or decorative shapes parallel to the edge of the workpiece.
3. Mold part of the edge of a circle, using a two-point version of the base guide.
4. Flatten a surface, using an extended version of the router base.
5. Rout a circle using a trammel that attaches to the router base like the regular base guide.
Guide System 3: Pilot on a Router Bit
The solid pilot or ball-bearing pilot runs against the workpiece edge. The guide is the pilot bearing. The fence is the workpiece edge. The offset is the distance from the bearing’s outer diameter to the cutting circle. When the workpiece edge is the fence, the bearing can only shape part of the edge. The rest of the edge must remain untouched, else the cut would go out of control. With this guide method you can:
1. Make a rabbet. One way to adjust the size of the rabbet is to change the diameter of the bearing on the bit.
2. Mold part of the edge of a board.
3. Rout a groove or slot in the edge of a board.
4. Rout multi-part shapes. When a template is the fence, the bit can remove all or part of the workpiece edge. You’ll get the best view of what’s happening with the template on top and a shank-mounted bearing. When the offset is zero, this setup reproduces the shape of the template. This is the most accurate way to reproduce a curved or complex shape. It’s how most dovetail jigs work.
Guide System 4: Guide Collar on Router Base
The guide collar runs against a template. The guide is the outer surface of the collar. The fence is the template. The offset is the distance from the outside of the guide collar to the bit’s cutting circle. With this system you can:
1. Make practically any shape, recess or hole in or through a board.
2. Cut a board’s edge straight.
3. Make a rabbet or a groove parallel to the edge of the template.
4. Make an inlay and a matching recess in the workpiece.
This setup works well for straight cuts. When you use guide collars with a shaped template, the template has to be adjusted to compensate for the offset. Adding and subtracting offsets from templates is a source of much confusion, and most people have to experiment before they understand how it works and rout a recess that exactly fits an inlay. cuts. When you use guide collars with a shaped template, the template has to be adjusted to compensate for the offset. Adding and subtracting offsets from templates is a source of much confusion, and most people have to experiment before they understand how it works and rout a recess that exactly fits an inlay.