Monday 9 July 2018
There are many ways to taper a table leg, some easier than others. After trying numerous methods over the years, I have settled on one method that is quick, safe and accurate. It depends on a jig I designed myself, which is used on the tablesaw for legs about two and half inches square or less. The same jig made for the bandsaw allows much larger legs. I once used this jig design on the bandsaw to taper bed posts over 6ft long.
I have seen a lot of jigs for tapering table legs, both shop-made versions and commercial ones. Many of them seem unsafe in the way that they hold the leg to the jig and some do not even hold the leg at all. Some can only taper a leg on up to three sides, not all four. Some are limited in the leg length that can be handled.
One of my pet peeves is jigs that take a whole weekend to build to accomplish work of no more than an hour. I am also not fond of jigs that are limited in what they can do so that I have to build a new jig all the time.
The jig you see here can handle any leg length up to that which you choose to build the base of the jig. I have mine around 40in long, so it can handle any leg length from about 36in and under. I have made longer jigs, but most legs I make are under 30in for dining tables, occasional tables, coffee and end tables, etc. This jig can also handle any taper angle I choose and any leg size that the blade height can manage.
The support block at the front of the jig stays in one place, but the rear block can be moved anywhere it is needed after drilling just two holes in the base.
The beauty of this jig is its versatility. You can build it in very short order and it will easily taper hundreds of legs before wearing out. Most importantly, it can handle any length leg within the capacity you choose to build the base, as well as any taper angle. Not many jigs give such a large payback for so little effort invested up front. I hope you enjoy using it.
The jig starts with a hardwood runner milled to fit the right mitre slot exactly. I prefer quartersawn oak because it is hard and does not expand and contract too much in width with humidity changes. Then a plywood base is attached to the runner right on the saw.
I use 12mm Baltic birch for the base, as any thicker would limit blade height capacity even more. For much longer legs or bed posts, you will have to use a 19mm base. Making the jig for a bandsaw gives you much greater cutting height.
When the plywood base is attached to the runner, leave it somewhat wide on the left side, extending beyond the blade, then cut the left side off while running in the mitre slot, using the same blade you would normally use to taper a leg.
I prefer a 24-tooth rip blade, use of which means that the left edge of the base represents the exact cut line of the saw with that blade – important when positioning a leg inside the jig.
Now make the two support blocks with suitable hardwood, such as beech or maple. The positioning of the holding screw is not critical, but I prefer that it bites into fresh wood every time I turn the leg.
Also, ensure that the screw on the front support block, which holds the bottom of the tapered leg, will be able to grab somewhere near the centre of the leg, otherwise the screw will have nowhere to go after having tapered several sides. On my jig, this screw is positioned three-quarters of an inch from the bottom and left edge. The same works well on the rear block, or 1in from bottom and left edge.
You will see a pencil mark just one-thirty-second of an inch from the left edge of the base where pencil lines for the leg tapers will be aligned. The key to this jig is that it cuts a taper that is parallel to the desired taper but leaves one-thirty-second of an inch of extra material to smooth the surface afterwards.
Final smoothing must not extend the taper up the leg at the top where it will travel underneath the joinery for the apron or skirt. The small cutout on the left side of the front support block simply gives a clearer view of the pencil line drawn on the base of the jig when securing a leg.
Marking and cutting leg
This jig does not require that the full taper be marked on each leg. Start with only a pencil line around the top of the leg indicating where the taper should end. I draw this line about a quarter of an inch below the table skirt in case I overshoot it slightly when jointing the tapers later. A bit of leeway is nice to have.
At the bottom of the leg, mark a cross hatch showing where the taper will end. For the 2 x 2in leg shown here, it tapers down to 1 x 1in at the bottom.
Place the leg in the jig with the upper pencil mark aligned to the pencil mark on the jig. Do the same at the bottom of the leg. Once again, because the pencil mark on the jig base is one-thirty-second of an inch away from the cut-line of the blade, the leg will be tapered a little less, but still parallel to the desired final placement. This is important because a jointer will simply smooth a surface in the same plane.
Now tighten the two holding screws until about they are about one-eight of an inch deep into the leg on both ends. For legs where the top might be seen, as with an exposed chair leg, a thin piece of plywood attached with double-sided tape prevents screw holes.
After tapering one side of the leg, rotate clockwise in the jig for the next cut. If tapering on all four sides, this means the underside of the leg will not be tapered until the fourth cut.
For this last cut, a stack of business cards under the leg supports it so that the top of the leg sits parallel to the jig base. A few minutes later, the leg is tapered all around and ready for final smoothing.
While a hand plane can be used for final smoothing, a power jointer easily does the task. Remember to read the grain as some sides of the leg must be cut starting at the top of the leg and others from the bottom. Final strokes with a hand plane will remove mill marks. Often a card scraper and sandpaper are all you need to complete the leg.
I have read articles that explain how to shim a tapered leg while cutting joinery or routing decorative details at the top of the leg. I prefer to complete routed details and joinery first and taper the leg last. For some joinery methods, such as using dowels with a dowelling jig, the order of operations may not be important. It pays to think ahead and choose the simplest order of operations.