If it’s time to purge the scrap bin or you’re just looking for a way to turn your router into Santa’s mechanical elf, here’s a clever little project to try this holiday season. You may have seen “waffle” style trivets before, but we’re giving ours a twist by milling them with a router mounted on a pivoting trammel jig. Stopping the swooping cuts short of the edges of the trivets creates a “captured” one-piece design, or you can rout right through the edges of the blanks and wrap a frame around the routed core as seen on the facing page. I used a 1/2"-diameter spiral bit and 3/4"-wide spacers to form this pattern, but you could certainly experiment with other bits and spacer sizes to produce more unique styles. The only requirement is that the bit be set slightly deeper than half the thickness of the trivet. That way, a series of cuts on both faces opens up the lattice pattern. Once you have the jig built and your blanks made, these trivets are perfect for production-style gift making.
Building the Trammel Jig
The jig is really simple to build. Start with a 22"-square scrap of 3/4" plywood or MDF, and draw a diagonal line connecting two corners. Cut a 6"-square trammel support from 1/2" scrap and bisect it with a pencil line. Fasten it to the base with glue and brads so the outermost corners of the support align with the edges of the base and the pencil marks of the two jig parts line up. Now rip a pair of 1/2" by 2" fences, cut them to an overall length of 15-5⁄8" and miter-cut one end of each to 45°.
Butt the fences against the support piece so the tips of the miters touch. Make sure they form a square “pocket” for the trivet blanks to register against before nailing the fences to the jig base.
Line the “field” area inside the fences with sandpaper attached with spray adhesive. Later, this will hold the trivets stationary as you rout them. I left the base’s outer corner bare where the trivets and spacers don’t reach it.
Adding the Trammel
The trammel is a scrap of 1/2" material cut 6" wide and 20" long; this width fit my router base nicely. If your router has a wider base, change the trammel width to suit it. Set the router near the trammel’s end to mark mounting holes for screws, as well as to establish where to bore a clearance hole for the router bit. Mark the trammel carefully with two layout lines: one identifying the centerpoint of the router bit and a second drawn 12" back from this line, before making the bit clearance hole and fastening the router to it.
You’ll need one of your 6"-square trivet blanks to mount the trammel properly on the jig. With the router bit installed, set the trivet blank in the corner formed by the fences and balance the trammel on it and the square support block. Slide the trammel along the support until the inside edge of the bit just kisses the outer corner of the trivet blank.
Make sure it lines up evenly over the support before boring a 5/16" dowel hole through the trammel and support — right into the base. Center this hole on your 12" layout line drawn previously. Now insert a 2" length of 5/16" dowel to engage the trammel’s pivot action. You’re nearly ready to start routing trivets, but first, make up 14 spacer strips from 1/2" scrap. Mine were 3/4" x 14".
Making Tricked-out Trivets
After you’ve prepared some snazzy trivet blanks (I tried patterns of contrasting species, glued side-by-side or as two 1/4"-thick face-glued laminations), making the trivets is easy. Set one pair of spacers against the fences so their intersecting ends overlap in the jig’s inside corner. Set your bit depth, and lock your plunge router’s base accordingly. For trivets with stopped router cuts, I drew layout lines 1/4" in from the edges of the blanks to set the starting and stopping points for each cut. Trivets with separate frames don’t need these lines.
Start the router and make your first cut, milling to final depth in two passes. I used a 1/2” upspiral router bit — but any sharp straight bit should do fine. Swing the router clockwise or counterclockwise — either works fine, but keep the trammel pressed down firmly against the trivet blank to prevent it from shifting.
Once you complete the first cut, pull the trivet forward, insert another pair of spacers and repeat for the second, longer “swoop.” Continue adding spacer pairs between subsequent cuts until you reach the other corner of the blank. Now flip the blank over, give it a quarter turn to establish the “X” pattern and repeat the whole routing process. This time remove one pair of spacers after each pass.
In minutes, you’ll have your first trivet knocked out and be on to the second. Sand away any bit burn marks or fuzz, and round over the edges. For trivets with frames around them, I used quick-set epoxy to secure the mitered frame pieces.
The recipients of your curvy kitchen coasters will no doubt appreciate their delicate look ... but secretly you’ll know that the bigger satisfaction — plowing those arching cuts and seeing the pattern develop before your eyes — was really all yours.