Why round cabinets? Because I had these perfect book-matched maple burl pieces that I wanted to use as cabinet doors, and cutting any piece of them off felt like a massive waste. Then I found two old brass port holes and decided to use them as cabinet doors too. By this point, I was basically fully committed to the idea. Bonus points since the girlfriend doesn't hate the concept.

Supplies

Doors, Drums, Glue, Clamps, Veneer, Yoga Ball, Yoga straps.

Step 1: Doors

A friend called me a while back about a burly maple tree that fell in the neighborhood. It sat in a series of sheds for a few years until I worked up the courage to buy an Alaskan Mill and a bigger chainsaw. Now I have more maple burl than I know what to do with. The doors were the inspiration for this whole project.

Step 2: Drums

Plywood cylinders are expensive, I learned this through experience. It occurred to me while searching for less expensive cylinders that drums are made of wood, and can be found used. I suspect every town of has at least one person selling old crappy drums. In the case of Somerville MA the guy's name is Michael. He drives an old white van and his house, yard and shed are full of drums and records. I'm lucky to have met him. For relatively short money I was off to the races.

Step 3: Cutting the Drums

Cutting cylinders is a stressful endeavor, but all in all not difficult. The table saw is the tool of choice. I thought about making some sort of jig for this cut, but the fence worked just fine. Unsurprisingly the drums where the outermost veneer layer runs circumferentially rather than vertically cut cleaner. In the future I'll be more decerning about my drum choice.

Step 4: Veneering the Drums

Here is where it helps to have a girlfriend who is into yoga (and does't mind you borrowing her workout gear for wood working).

Before veneering, I filled the hardware holes with wood filler and sanded them smooth. I didn't want to leave big voids in the cabinet or have visible indents when the veneer was applied.

Last time I had to veneer the inside of a cylinder (https://www.cobyungerdesign.com/work/gif-irl-1) I made a giant clamping jig out of MDF and used a ton of clamps to get enough pressure. This time I decided to get clever and used air pressure instead. A yoga ball inflated inside the drum worked amazingly well.

The other tip in this process was to leave the veneer a little extra long and apply tape on the inside on both ends. This way, the ends don't actually stick. See the next step for why.

The outside of the drum was done similarly, but with resistance bands instead of a yoga ball. Yeah, I know, almost a full set of Pilates gear here (I think).

Step 5: Veneer Trimming

Once the glue is dry, the ends will peel up quite easily since they had duct tape and thus did't glue. First, clamp a straight edge in place and cut through both layers of veneer. Then you can go ahead and remove the tape from the inside surface of the veneer on the ends. Lastly, apply glue inside the flaps and apply pressure with the ball or straps again. Be careful with this step. I learned the hard way that it is really easy to break the flap off and then you've ruined the seam. The other thing I learned the hard way was to be really careful with the knife cut. Without a straight edge, it is really tough to get a nice seam.

Step 6: Making Segmented Rings

I love segmented ring construction. See my Instructable on the Wooden Zoetrope (https://www.instructables.com/Wooden-Zoetrope/) for more info on this process. I started with a straight board, and cut trapezoids with my segment cutting jig. The ends are cut at 75º angles and length was calculated to ensure that a circle circumscribed would fit well within the 12 sided ring. In this case it was 5.75 inches on the long side for a 20 inch ring.

Step 7: Cutting Rings

Some people think CNC cutting is cheating. What do you think? For me, CNC is a tool among many in the wood shop and allows me to make more complex pieces with fewer jigs and less time. I designed a couple parts in Fusion 360, and ran them on the Techno CNC router. Before cutting, I hot glued each ring to a piece of thin plywood in order to more easily attach it to the bed of the machine. This also gave me an easy way to zero the machine to the center of each ring.

Step 8: Shelves

Shelves were the trickiest part of this project. They are made from birch with edges of cherry. The center support is a full inch in width. Probably thicker than it needs to be, but this is where the shelves are supported and where the hinges for the doors need to attach. I took measurements from the CAD model, but cut the dados in the ply with a table saw. The solid cherry covers up the dado joinery. The shelves are cut at an angle on one side that matches as close as possible to the curve of the shell, and straight on the other to fit in the dados. I put off the final glue-up of this piece for weeks because I was so nervous about it. In the end it is so strong I could probably stand on it on the side without damage (not that I plan to).

Step 9: Sanding and Finish

Sanding and finishing is always a delightful way to enjoy the natural beauty of wood.

A few steps are not pictured. These include the backing on the door, hinges, and hanging with a french cleat. I used "European" hinges.These are the ones that require a forstner bit hole in the door and have screws for adjustment. I suspect they call them "European" just because it sounds fancy.

I backed the door with 1/2 inch ply to give space for the hinges and to keep them flatter and more rigid over time. I am hoping to have this cabinet for the rest of my life.

I cut a piece of 3/4 ply at a 45 degree angle and glued one side to the back of the cabinet. the other side got screwed to the wall. They call this a french cleat, again I think because it sounds fancy.