Just a few photos showing the tusk tenon. This was discussed in Part One.
The wedge mortise was cut before finish trimming the tenon. That gave as much support as possible for chiselling.
The lateral gap was kept as tight as I reasonably could. After all, the cross grain direction in all members is the same.
The sides of the wedge were relieved, somewhat like a clamping caul. The wedge will bend a little when driven home. If the sides were straight, they would apply pressure at the ends on the mortise, and lift at the ends of the wedge. The amount was arrived at by checking for gap between wedge and leg. I used a feeler gage, but a piece of paper would serve, paper being around .003 or .004 [0.08 or 0.1 mm] thick.
If the wedge is very broad, as in the Moravian bench, the flex will approach zero, but my wedges did, quite noticeably. I imagine I cut some .012 to .016 [0.3 to 0.4] away.
The legs are tapered, one degree all round. This didn’t affect much, but it did force some care in cutting the leg mortise – carefully sized, and square, on both ends, just like any mortise. But the depth prior to any undercutting had to account for the leg tapers. And the wedge and wedge mortise was cut accordingly.