Four Sided Tapered Leg Jig

While creating a statement furniture piece from a 1960's cabinet my wife asked me to replace the original legs with more elegant four-sided tapered legs. That's when the fun started! Cutting a two-sided taper was easy but four sides, that's another story.

After much research and creating a small pile of kindling, it finally struck me that such approaches as packing up the first two sides to ensure the same taper on the other two sides was a rather crude, time-consuming, and somewhat hit-and-miss exercise.

My solution to the problem was very quick and has encouraged me to pass on the idea in my first ever Instructable!

It occurred to me that it was very similar to turning a tapered round leg on a lathe. You had to ensure that the top end of the leg was able to be temporarily fixed while the bottom end was able to rotate on the same axis to cut the next side to get exactly the same taper. I, therefore, built a jig to fit the required width of the leg and then created the other end with a tapered steel pin with vertical and horizontal adjustment.

The idea behind this jig is similar to a lathe with the top of the leg fixed and the thinner bottom of the leg held by a pivot pin set at half the width of the bottom of the leg. As you rotate the leg the saw cuts off the protruding timber to create the same taper on all four sides. The jig will let you cut four tapered legs in less than 10 minutes.

The horizontal adjustment pin was set to half the required bottom width of the tapered leg while the vertical adjustment was set to half the top width.

I created some toggle clamps to secure the timber stock in place. One clamp was used to hold the top of the leg against a secure fence while the second clamp was used to lightly clamp the bottom which was held in place by a steel pin clamped firmly against the center of the bottom of the leg. The jig was then run through my table saw to create the first taper. In practice, I found that you only need one clamp at the top end of the leg as the centering pin at B holds the bottom end firmly in place once the leg is pushed against it and then clamped firmly at the top end. You could use one clamp and simply move the clamp depending on the length of the leg.

The other three tapers were created by unclamping the top toggle clamp and rotating the leg in the same direction and then retightening the toggle clamp. There was no further measuring or adjustment required. Each leg took approximately four minutes to complete.

The legs were attached using a threaded steel rod epoxy glued into the legs. These were screwed into timber plates containing a T nut and with the timber plates then attached with four screws to the bottom of the cabinet. I discovered it is a good idea to drill the holes for gluing the rod before cutting the tapers as it is almost impossible after they are tapered!

User Instructions:

First, mark out centers on the top and bottom of legs using intersecting diagonals.

Make sure to drill any holes in the top for any dowels/bolts being used to attach the legs as it can be awkward once the legs are tapered. For a reasonable vertical hole simply use your drill press. Drill a block the same size as the top of the leg and then clamp this to the end of the leg and drill your hole to glue in a dowel or screw in a threaded rod with epoxy.

Drill a small hole in the center of the bottom of the leg to center the alignment pin “B”.

Mark where tapers will start on all four sides on each leg as a reference when cutting. Number each leg consecutively from 1 to 4. This shows the sequence in which you will cut each side.

(1) Clamp top of the leg at “A”. If your leg is a different size, simply move the 3 screws securing the fence to fit the width required. ( An upgrade would be to router a channel in the baseboard to clamp and adjust the fence to the width required)

(2) Adjust the vertical slide bolt so the CENTRE PIN (“B”) is half the height as the top of the leg and tighten to secure the center of the bottom of the leg.

(3) Adjust the horizontal slide to place the pin at half the width required for the bottom of the leg.

(4) Secure the timber firmly with the toggle clamps.

(5) Make your first cut and rotate to leg side 2 and re-clamp.

(6) Repeat for each side.

• 8mm threaded steel rod
• 8mm Wingnuts
• 8mm T Nuts
• 8mm Washers
• 20mm thick Hardwood for Toogle Clamps
• 20mm x Brass or Aluminium Rod or Dowel for Toogle Clamps
• 200mm x 800mm x 20mm Pine for the base of jig.
• 200mm x 40mm x 10mm plywood strips to raise the base for recessing adjustable screw.
• Screws
• Wood glue