One of the best ways to get more out of your router is to replace the plastic baseplate with an accessory base attachment. Although you can buy manufactured bases, I get the same results from my own shop-built attachments. They don't take long to create, and because they're made out of scraps, they cost almost nothing.
On the following pages you'll find my favorite router base attachments for seven common woodworking tasks. Because different routers feature different baseplate styles, I have focused on the basic construction and working principle behind each attachment - you can adapt the jigs to fit your router and use the ideas as a springboard to create bases that will suit your woodworking needs. Whatever type of jig you build, be sure to position the tool handles in a comfortable location when mounting the jig on your router.
Multiuse Extension Base
In addition to the increased stability a larger base provides, this single extension base adds versatility. Attach a fence and it works great as an edge-guide extension for cutting dadoes in panels (left photo). Or drive a nail through it to serve as a pivot point and you’ll have a perfect circle-cutting jig (right photo). I once cut a 20-ft.-dia. arc by attaching extensions to a base like this. This is also one of the easiest jigs to build. Just cut a 1/4-in.-thick piece of hard-board to the same width as your existing router baseplate, and make it as long as you like.
Everyone who works with veneered panels faces the time-consuming task of trimming the edge-banding flush with the veneered surface. I get the best results by running a router over the top of the protruding edge-banding. This base attachment adjusts to accommodate various banding against the edge of the panel thicknesses and positions the bit so that the blade makes contact at a nearly 90-degree angle. It also allows you to press the router securely to counteract the tendency of the router to buck away from the work.
Trimming inlays flush with the surrounding surface is a lot easier with this base attachment. The router bit is lowered through the base until it barely skims the surface of the panel. Then you slide the base along the surface until the bit shaves away the projecting inlays. To keep the router from tipping and gouging the surface, the base attachment extends outward, providing a place to rest your hand as a counter-weight, and a spacer block is attached on the opposite side of the bit.
It’s easier to catch dust at the source than to sweep up a shop or job site. Many new routers are equipped with dust ports, but these two base attachments permit you to retrofit any model. Both bases feature a block that the vacuum hose fits into. If you don’t have a drill bit that exactly matches the vacuum hose diame-ter, drill a slightly oversize hole and wrap the end of the hose with duct tape for a snug fit. If the hose vibrates out, use a small wood screw to hold it in place.
The first base is intended to be used for the same operations as a standard flat router base, with the added benefit of dust collection. You can improve the effectiveness of the dust collection by shrinking the hole where the bit enters the attach-ment and enlarging the spacers that separate the flat panels, enlarging the slot opening. This permits a strong current of air to blow across the cut from the side.
The second dust-collection base is a guide fence that can also be secured to a bench and used as a small router table. The position of the fence is determined by the bit you are using. Note: The fence must be securely attached to the base because it carries the additional weight of the hose. Build up the hose-connection block by gluing two smaller blocks to the fence piece. Next, bevel a V-channel in the face of a 2x4 to make a drilling jig. Then drill the hose hole diagonally through 1-3/4 in. the fence, using the V-channel 2x4 for support.
Custom Dado Guides
Dadoes should be cut to the exact thickness of the stock that will fit into them. Unfortunately, the thick-ness of stock often doesn’t exactly match any router bit diameter. These two base attachments enable you to increase the width of dadoes without changing bits or resetting a guide fence.
Incremental-width dado jig
The first jig is designed to increase the dado widths in established increments. Each edge of the base is a specific distance from the edge of the bit, so to increase the width of a dado you simply rotate the base to run along a different side and then make another pass. The biggest advantage of this base is that it produces consistent dadoes of any width you need. Make the base by first mounting an oversize square panel on the router base. Next, install a 1/4-in.-dia. steel rod or bit in the router’s collet. Make a mark 2-7/8 in. from the edge of the rod — that puts the mark 3 in. from the center. Knowing that one edge is exactly 3 in. from the center makes it easier to correctly locate the fence. Then mark the remaining sides at increasing distances from the center. Finally, before you remove the panel to cut it to size, make a tick mark both on the base and on the panel so that you will be able to remount the panel in exactly the same position.
Variable-width dado jig
This jig offers even more flexibility because you can increase the width of a dado in variable amounts to match the exact thickness of your stock. Half of the base is concentric to the bit, whereas the other half spirals out 1/2 in. farther. By rotating the router a controlled amount when you make the second pass (bottom photo), you can expand a dado by whatever increment you wish until you achieve the right fit. Although the incremental-width dado jig is better for repeat work, this variable base is indispen-sable for custom fitting. Accuracy requires that you establish an edge that is exactly concentric to the bit. First, drill a 1/4-in.-dia. hole through the center of an oversize square base. Slide the base over a 1/4-in.-dia. steel rod or bit mounted in the collet and draw a line around the rod using a homemade 3-in. beam compass. Mark the base and the panel with tick marks so you can reinstall the panel in exactly the same position. Draw the spiraling edge with a conventional com-pass from a point 1/4 in. from the original center point (photo 1). The spiral arc begins as a tangent to the original circle, and 180 degrees later it ends up 1/2 in. beyond the circle (photo 2). Carefully cut the base along the spiral-arc cutting line.
Club member John Kriegshauser designs, builds and restores furniture in Chicago, Illinois.