Leg Joint DetailIn my previous post about my desk, I mentioned that the legs had experienced a catastrophic failure. Today I rebuilt the legs based on the lessons I learned from the previous attempt. The new construction uses a hanger bolt through the corner brace. I also changed the way I attached the corner braces to avoid producing weaknesses in the wood.

Failed Corner BraceOne of my corner braces split into three different pieces when the leg failed before. Looking at this picture, it is very obvious that the split happened because the screw forced the wood grain apart. To avoid that I made up a jig to recess the screw holes at a 45 degree angle to the brace. I then drilled a pilot hole and countersunk the screws. This has provided a secure attachment for the braces without stressing the wood grain.

The other difference was the use of hanger bolts rather than an insert nut and a 1/4" bolt. If you're not familiar, a hanger bolt has a wood screw on one end and machine screw threads on the other. The wood screw portion is long enough and thick enough that it won't come out unless the leg itself splits. That give me the ability to snug the legs tightly to the rails of the desk, making it look better and more secure.

A lot of this construction was also helped by the purchase of a sophisticated doweling jig, called the AccuDrill. It let me drill and accurate hole at the corner of the leg to a controlled depth. Ideally I would use a drill press for this operation, but my little shop doesn't have room or budget for a drill press yet.