While raised-panel cabinet doors are great-looking, sometimes a flat-panel door fits the overall look and design of the project better. The Shakers are probably the best known for flat-panel doors, except their doors were actually raised panels turned backward. In a time where plywood was not an option, gluing up the door with the raised panel facing inward was the only option to get a flat-panel look on the exterior of the door.
Fast-forward to today and we have a variety of plywoods to choose from to make inexpensive flat-panel doors whether the cabinets will be painted or veneered with beautiful hardwood veneer. The biggest problem with modern 1/4" plywood is that more than likely it is not a true 1/4" thick, rather it is marginally thinner. This causes a problem when using a standard rail and stile router bit set that makes a true 1/4"-wide groove. The plywood will not fill the groove and allows the panel to rattle.
Fortunately, Infinity Cutting Tools offers plywood slot cutter sets for their rail and stile router bit sets that create perfectly sized grooves for plywood. The slot cutters allow you to fine-tune the rail and stile router bit set to make the perfect size groove no matter how thick or thin your nominal 1/4"-thick plywood is.
The plywood slot cutter set (left, above) creates perfect-fitting grooves for four different thicknesses of nominal 1/4"-thick plywood. Plywood Slot Cutters from Infinity Cutting Tools feature thick, micro-grain carbide cutting edges that stay sharp longer, an anti-kickback design for safety, a non-stick coating that's easier to keep clean, and a three-wing cutter for the smoothest cut.
Installing the plywood slot cutters in the matched rail and stile router bit sets is easy. Let me walk you through the process so that you can attack your next flat panel cabinet door project with confidence.
The Infinity plywood slot cutter router bit sets consist of two slot cutters that replace the 1/4" slot cutters in the standard Infinity rail and stile router bit set. The plywood slot cutter sets are available in 4 different sizes including 3/16", 5mm, 7/32" (5.5mm), and 15/64" (6mm). They're also available in a convenient, money-saving master package.
The slot cutters are laser-etched with the size of groove they make and which rail or stile cutter they go with. This is important because they are not identical. The carbide on the slot cutter marked "rail" is offset and overhangs the bearing on the rail router bit, and the slot cutter marked "stile" is sized to account for this offset to make the poperly sized groove for your plywood panel.
As long as you pair the plywood panel slot cutter with the correct bit you can't go wrong. I like to take my router bit and lock it into my router table using the shaft lock on the Triton router. This makes it easy to remove the nut on the top of the router bit so I can swap out the slot cutters.
Swapping out the slot cutter on the rail router bit is simply a matter of removing the nut and washer, removing the 1/4" slot cutter, and then replacing it with the slot cutter marked "rail" from the plywood slot cutter set. Reinstall the washer and nut then tighten everything down.
Swapping out the slot cutters on the stile bit has one extra step. I follow the same procedure except that after removing the nut and washer, you'll also need to remove the bearing that sits on top of the 1/4" slot cutter. Underneath the bearing is another washer that acts as a spacer to allow the bearing to spin freely without rubbing. Once the nut bearing and two washers are out of the way, remove the 1/4" slot cutter and replace it with the slot cutter marked "stile" from the plywood slot cutter set. Replace the washer, bearing, top washer and nut and tighten everything down and go to work. Infinity Cutting Tools provides detailed instructions for assembling these bits to ensure they cut perfectly matched joints.
