Last time I ended up with the undercarriage and seat all glued up. I had the hole locations for the back spindles in the seat all set, but I needed to see where they would go in the crest rail. So I clamped the crest rail to the seat posts and laid the spindles where they looked right.
|Spindles spaced to look good|
The spindles tend to roll out of position when doing this, so rubber bands are your friends. Here's one way to keep them in place. I could have done the same with the crest rail too.
|Rubber bands holding the spindles in place on the crest rail|
I didn't get a picture of boring the 3/8" holes in the posts for the crest rail tenons, but the method is pretty cool. With the crest rail clamped in place, just center the bit on the post and bore parallel to the rail. It works great.
|Crest rail tenoned into seat post mortises|
|Close-up of one side|
To bore the holes in the crest rail for the spindles, I placed the posts and crest rail in position and sighted down to the seat spindle-hole locations. The holes in the crest rail were bored only deep enough for the lead screw to poke through the other side.
|Boring the hole for the right-most spindle|
A simple technique I learned from one of Curtis Buchanan's videos was how to come back from the opposite side to complete the through holes. He puts a dowel in the hole and uses it as a guide to line up the bit when boring in from the other side. Simple, but genius.
|Completing the through mortise from the underside using the dowel as a directional guide|
Then, with those holes bored and the posts and crest rails back in position, I could bore the holes in the seat. This might be the first time I've ever used the ratcheting feature of a hand brace. But as seen in the next picture, I had to use the ratchet. After putting the lead screw on the hole center, I sighted through the corresponding crest rail hole to get the proper angle.
|Boring the spindle mortises in the seat|
|My view of same|
And here's the back assembled for the first time.
After that, it was a matter of trimming the tenons so that just 1/8" or so protruded. The tops of the posts were also cut to proper length and chamfered. Then, I glued it up with wedges and hide glue, and when the glue had set, the tenons were rounded (or domed) to give them a nice look.
|Tenons wedged and glued, ready for shaping a dome|
|Done and dusted|
This was a really fun project. I can't help wondering how different it would be if I could get some "green" oak for the legs, posts, crest rail and spindles, and a big plank of white pine for the seat, and a scorp and a ... Oh well, until then I'll continue to make do with what I have.