# Table base joining elements at 45 degrees



## dglefty (Jun 12, 2020)

I am designing a table base with the bottom of two table leg assemblies connected together at 90 degrees and this assembly connected to a bottom stretcher as shown in the picture. The table top will be heavy so I am looking for strength in the joinery. I am looking for suggestions for designing the junction of the three elements. My current plan is to miter the two 45 degree elements together and half lap that to the stretcher.









The view from the bottom shows the arrangement of the pieces and I am considering pulling all this together with a triangular wedge in the V formed by the table legs.









I am concerned however of the miter of the two legs separating, and I'm not confident in my joinery skills to create a V-shaped lap joint cutout in the stretcher to accommodate the full miter joint. Is there a way to improve this junction that looks good and provides strength to the base?


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## bilyo (May 20, 2015)

First, which side is up? Will the joint be visible as if it is lying on the floor with the table top resting on ends of the legs. Or, will the joint be hidden by the table top resting on it in a more conventional manner?

Either way, I'm afraid that the half-lap will weaken the mitre joint. I think I would make a complete mitre joint and reinforce it with dowels or cross splines. Since you will be gluing end grain to end grain, you may want to consider using epoxy for this. Then make a "V" cut in the ends of the stretcher to fit snugly against the mitre point. Then make a triangular block to fit into the "crotch" of the mitre and run a pair of long lag bolts through the block and mitre into the stretcher to hold it all together. If all of your cuts are true and fit tightly, it should be pretty strong. Of course, you can counter sink the bolt heads and plug them if the joint will be visible.

Another way to do it would be to mortise the mitre cuts into the sides of the stretcher then glue and reinforce with dowels or screws. This would also be stronger but, your cuts would be a bit more complex.


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## dglefty (Jun 12, 2020)

The first picture is the top view. Shown is the joinery at the bottom of the legs, but there will be a matching joint on the top of the legs supporting the table top. Thinking more of the problem since your comments I came up with a bridle joint design of sorts, or maybe a double halved joint, not sure what to call it. Basically a lap joint on top third of the stretcher cut at a 45 to capture one of the legs and separate lap joint on the bottom third cut at the opposite 45 to capture the second leg. I could optionally dowel the whole thing from top to bottom. This picture shows the cutouts of the stretcher to illustrate the concept. thoughts?


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## bilyo (May 20, 2015)

I'm not a structural engineer but, my gut doesn't feel too comfortable about it. The two 45 deg membesr are the ones taking all of the tipping stress and, I think, the miter joint should be made as strong as possible. The stretcher will only have to withstand mainly minor tension or compression along it's length with some minor twisting. An alternative to my previous suggestion would be, again, make the miter as strong as possible. Maybe even go so far as to use finger joints. Then cut a through mortise through the center of the miter to hold a tenon on the end of the stretcher. This way, the forces on the miter will be equal top and bottom.


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## dglefty (Jun 12, 2020)

bilyo, thanks for your insights. Very good suggestions.


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