I realized that it might be a little mysterious how those sawhorses I made actually fit together. Here are some assembly instructions.
You’re going to need two feet, two legs, one stretcher, one top, two pegs, and two wedges. The legs have a wide end and a narrow end. The feet have one mortise in their top sides. The top has two mortises in its underside. you’re also going to need a small hammer or mallet.
Insert the wide tenon of one leg into the mortise in the top side of one foot. It is very tempting to hammer the top of the narrow tenon, but this may mash it making ti difficult to insert later, so resist the urge.
Use the mallet to hammer a peg all the way through the sideways through-mortise in the foot. These are designed to be drawbores, which means that the mortise in the leg does not line up perfectly with the mortises in the foot. This makes it more difficult to hammer in the peg, but as you do so it draws the joint tighter.
Repeat those steps to assemble a second leg/foot combo.
Insert the stretcher between the two legs, sliding the tenon at each end of the stretcher entirely through the sideways mortise in each leg. Note that the wide dimension of the 2×4 is vertical. The mortises and tenons are square, so make sure the stretcher isn’t sideways.There’s no “inside” or “outside” to the legs, so whichever way fits better, just go with it.
Insert a wedge into the through mortises that run vertically through the tenons at each end of the stretcher. Hammer these nice and snug, or the resulting horse will be wobbly.
Slide the top down onto the tenons at the narrow ends of the legs.There should be enough tension in the assembly to hold the top firmly in place once the horse is assembled. If there is too much tension, and the top just won’t go on, remove the wedges to release the tension, add the top, then replace the wedges.
Ta-da! Now do it three more times. You made four, correct?