So let's see - last time on Let's Make a Door I had dry-clamped the lower rail and stiles together. The next move is to remove the inner stiles and cut the mortises for the through-tenons on the outer stiles. The trick was figuring out exactly how far apart the shoulders are (from the inside of one stile to the other.) Once I had that, I could chop the cross rails to length and cut the tenons on either end. The idea behind the cross-rails (the thin parts shown below) is that the will distribute some of the load from the inner stiles to the outer stiles, rather than have everything rest on the lower rail.
Detail of one of the through-tenons. Eventually it will receive two wedges, but I wanted to wait to cut the wedge-slots until right before glue-up so the end wouldn't get beaten too badly while fitting and re-fitting everything. The shoulder of the tenon is about halfway through the stile. Because it was such a long mortise, I routed it from both ends - one side to match the exact dimensions of the rail, and one side slightly smaller (thus making a shoulder), which was then chopped square.
One of the few full-scale drawings I've done. I wanted to be really sure each segment of the arch was exactly long and wide enough to complete the arch. It was also really nice to be able to compare the test pieces with the drawing without a lot of fuss.
Detail of the arch drawing. Not exactly Jefferson drafting the Rotunda, but it will work.
The arch segments are cut, and the glue-tabs have been glued and screwed on. Eventually each segment will receive four tabs (two on the "inside" and two on the "outside.")
Dry-run with all the joinery cut and loose tenons in place. The tabs are angled so that clamping pressure is exactly perpendicular to each joint. Once everything is glued up, the screws in the tabs will be removed, and the tabs themselves will be cut off. Another advantage of having the full-scale drawing for the stage was being able to see exactly where tabs needed to go and long the screws could be without putting holes in the final, curved arch.
Glue up time! Each outer stile was glued to two arch segments,and the joint through the middle of the arch was dry-clamped. The splines running between the segments were more to register the faces of each piece than for strength.
Setting up to rout the inside curve of the arch with the large trammel. Notice the clamps are still on the middle section of the arch...
The poplar piece shown here was the dummy rail used to center the trammel. It was sort of awkward to set up, but it seemed to work.
Speaking of awkward...This was the (sort of ridiculous) set up to cut the groove inside the curved arch. I'm positive there was a better way to do this - I just couldn't figure out what it was.
Cutting the groove. I used a 1/2" spiral upcut bit and a plunge router, and took about three passes to get to the final depth. The fences on either side of the router base correspond to the opposite wall of the groove. In other words, there is enough space between the two fences to cut a channel that matches the previously-cut groove the straight, outer stile.
The groove is finished, and should match the tongue that will be cut in the tops of the inner stiles. I had to use a laminate trimmer to freehand-rout the web left after the big Routerlympic Ski Jump .
Cutting the arch in the inner stiles. Notice that this arch corresponds to the outside width of the stiles, and will eventually be the tongue on each stile. The shoulder-arch (which corresponds to the visible parts of the stiles) will be cut during the same set-up, but with a slightly smaller radius.
Test-fitting the arch/stile assemblies to the inner stiles. Because of the through-tenons in the outer stiles, each half of the assembly has to come in from the side (hence leaving the middle of the arch dry during the previous glue up.)
One last test to check all the joinery and the reveals between the stiles...
Success! (Full disclaimer: this was actually the most stressful glue up ever. No kidding.)
The next day...
Routing the outside arch using the same dummy piece as a center for the trammel (drilling a 1/4" hole in the middle of the door at this point would be a reason for sadness.) Also, the shop-vac seems to be pretty much mailing it in this morning.
Using a jigsaw to cut the waste (including the glue tabs) off the arch...
All set. I used a template guide with a long bit to remove most of the waste, then I came back with a pattern bit to finish the job. Now I just need to make (and install) the window, build the jamb, finish everything, attach the hardware, and figure out how to move it...