With the brace finished, the rack was almost ready to assemble. I started by adding the top cap with some dowel joinery.

I also drilled some holes for (unglued) alignment dowels in the base and bottom edge of the rear panel. Those dowels enabled me to dry-fit the cart without using screws. Now I could verify that the racks could swing open without contacting the rear panel.

It was fun seeing how the finished rack would look with the racks folded closed.

Before sanding everything down to 220-grit, I also counterbored and drilled screw holes in the bottom of the base and skirt. I’d glue the brace to the rear panel and cap to form an upper subassembly that would be attached to the base with screws. I knew I’d need to tweak the dowel pivot hinges and washers, so I needed to be able to disassemble the rack.

With that done, I wiped on three coats of satin Arm-R-Seal to all the parts. As usual when prefinishing, the hardest part about that was finding a way to hold the parts while applying the finish and supporting them afterward to dry. I used a long clamp as a handle for the brace. I placed the base on a stack of bench cookies. The rear panel’s dado balanced on a long strip of scrap.

Because I had previously applied finish to the insides of the racks, I could hang them on the ends of more long clamps.

I left everything alone for a day or two before attaching 2” x 1 3/8” butt hinges to the two rack pairs. To give the rack sides a bit of expansion room, I used high-tech spacers (pieces of cardboard torn off a box of Mini Wheats cereal). The hinges are so thin I didn’t worry about cutting mortises for them.

 
I had applied one coat of finish inside the base, so I hadn’t attached the 1” casters (which have posts that screw into threaded inserts) earlier. When I attached them, I discovered a problem. I had drilled the insert holes about 1/16” too close to the edges. Some of the caster wheels rubbed the insides of the skirts and couldn’t rotate 360 degrees. Given that the base had an uncured finish on it, I didn’t want to muck around with it too much. I just placed it upside down on a padded surface and used a Dremel and grinding wheel to hog out some material where the wheels rubbed. It’s crude and ugly, but it will also be hidden, so I didn’t agonize about it too much.
 

Next, I glued the brace to the rear panel, and the cart was ready for assembly. Here, you can see the alignment dowels and screw holes in the base. I used four screws to attach the base—two 1 1/8” fine thread pocket screws in the brace and two into the rear panel.
 
 

The last step was cutting the 144 5mm dowels for the thread spools and bobbins. My first thought was 144 passes with my crosscut sled. The only problem with that (aside from it taking forever) is that I’d get some tear-out.

To prevent that, and to speed up the job, I made a simple jig from a block of scrap about 1/2“ wider than the dowels’ length. I drilled eight holes through the edge of that block close to the bottom. Then I set the fence to match the dowel length and cut a slot partially through the underside of the block (deep enough to extend past the holes).

To use the jig, I pushed eight dowel rods at a time (they came in 12” lengths) though the jig until they touched the fence.

I made a pass through the blade to cut all eight dowels (fully supported on both sides of the cut).

Then I pushed the cut dowels out and repeated the process. It went quickly, and the cuts were clean, requiring only a quick spin against a piece of sandpaper to smooth.

I didn’t think the dowels needed any finish, and my wife agreed, so all I needed was a small drop of glue (not enough to squeeze out through the top of the hole) in each spool block hole, and the cart was “finished.”

More correctly, the cart was ready to take inside for some testing. From the beginning, I was worried that it would be back heavy and would want to fall over backward. Soon, I’d know for sure.