Step 7: Main Assembly
LEGS, SEAT AND FOOTREST
Using the dimension drawing (image 3 of this step), measure and mark the legs with the pencil where the footrest and seat will be. Clamp the footrest and seat into place. Use the measuring tape, the level, your eyes and your excellent judgement to make sure everything is even and level. Check to make sure the tops of the legs are level and even by balancing the armrests on them. Once you're satisfied, drive a couple of screws part way in on each joint to hold it together temporarily.
Remove one leg at a time, apply glue generously to the joints, and reattach the leg with four screws at each joint. (I clamped a spare board to the chair to act as a fourth leg before I removed each leg.) Check to make sure nothing has shifted and do another leg. Repeat two more times.
I made a jig to hold the backrest in place while I measured for where the back slat would go, and for when I attached the back. The jig is made from two 2x4's screwed together at a 15 degree angle.
Using the jig, clamp the backrest in place. Position the armrests in place and mark where the bottoms of the armrests cross the back - this is where the top of the back slat will be. (If the temporary back slat is in the way, remove it carefully.)
Remove the backrest and attach the permanent back slat. I used two 2" screws for each of the nine back pieces - I was concerned that a 2.5" screw could go all the way through the back if I drove it in too far. NOTE: The back slat should have a 15 degree angle cut off the top of it, make sure this is properly aligned when you attach it. Also, the back slat should be too long, make sure to have extra length on each end - they will be trimmed after attaching the back.
With the permanent back slat in place and the temporary one removed, use the jig to clamp the backrest back onto the chair. Screw it to the chair with another 18 screws horizontally through the backrest support on the seat.
With the backrest in place, it's a snap to attach the arms. Line up the back of the arm with the back of the back slat, then glue the joints and put a couple of screws down into the back slat and each of the legs (six screws, total, for each arm).
Grab your hand saw and cut off the excess back slat, making it even with the angle of the arm (see pictures).
Hand sand any sharp edges.