Combination Router Base CRB7 Mk3A router base can be nothing more than just that: a base. Or, as in the case of the CRB7 MKIII kit from M.Power, it can be outfitted to help your router perform a multitude of other functions.
The CRB7 router base has been around a while, but the MKIII kit has a couple of important additions: two different-size guide rods to fit more routers, and the ability to cut larger circles. With the launch of the new accessories, I thought it’d be a good time to reintroduce the CRB7 for those who don’t know the versatility it can add to your router. On its own, the CRB7 is a solid, well-built accessory. It attaches to your router via two rods that go in the slots where you’d attach a stock edge guide.
The most obvious benefits of the CRB7 are its large surface area and that it’s offset. A large base increases stability when you’re routing an edge. The offset amplifies that stability by putting about two-thirds of the base on your work surface, as opposed to just under half, as is the case with a centered base. For routing on the edge of a narrow workpiece, where the base size doesn’t count, use the adjustable anti-tilt leg to provide stability.
With the MKIII kit, you’ll be able to rout perfect circles with a diameter as small as 3/4” to as large as 50”. Using the micro-adjust wheel, you can precisely dial right up to a line to adjust circle size.
This micro-adjust feature is also great for use with any clamp-on style edge guide for routing dadoes. A short edge guide that fastens to the base is also available. Using a shop-made guide attached to the base’s underside, routing a series of parallel dadoes is a snap, as the guide slides in the previous dado.
Using a set of posts attached to the base’s underside, you can cut centered or offset mortises. With the MKIII edge-trim kit, you’re also set up for precise flush-trimming of edge banding or plugs.
Bottom line: This is a whole pile of jigs in one relatively affordable package. I’d like to see a kit that includes all of the available accessories.