Conical Dining Table

For a few months I had a sketch of a table I wanted to build. It was a design that came to me suddenly. I hadn't made any round tables to date, and due to some construction uncertainties, I wasn't inclined to start it. Additionally, I wanted to make it a bit different from what I had commonly seen, so I simply came up with the idea of using two cones, one as the base and the other as the tabletop. I know I haven't invented anything new, and it's really just an aesthetic feature, but I liked how it looks that way. Anyway, here I share my construction process and some helpful tips in case you want to replicate it.

Well, this is the plan: to create a dining table that looks good, has a spacious surface, and can also be separated into two parts for easier handling.

Materials

• x1.5 Plywood 15mm (4x8 board)
• x1 Flexible Plywood 8mm (4x8 board)
• x1 Decorative Plywood 6mm (4x8 board)
• x4 5/16" x 2" Socket head Screws w/ nut & washer
• x4 Heavy duty L bracket (or some steel plate to make your own)
• Some scrap wood

My main powertools for this proyect

• Circular saw
• Jigsaw
• Router
• Power drill
• Brad nailer
• Orbital sander
• Welder (optional)

*Sorry for the mix between imperial and metric measurements but this is how I get my supplies :)

The idea behind this design is quite simple, as it is a radial model, it's easy to grasp each of its parts. So, I'll share the main measurements I used, and the missing ones should be easy to deduce.

The table consists of two independent sections, and each one is formed by an internal radial structure. I used a modulation of 16 (I'll refer to them as ribs) as the structure. It's important to use multiples of the same number so that the rest of the elements align correctly.

General dimensions: Height 76cm / Top ø 120cm / Base ø 60cm

Components

TOP

Main Circle: This is the largest part, and it connects to the core, ribs, and the decorative plywood cover.

• Material: 15mm Plywood
• Dimensions: ø1190 mm
• Quantity: 1

Core: It consists of 4 smaller concentric circles that overlap, reinforcing each of the ribs and also serving as anchor points for the L brackets.

• Material: 15mm Plywood
• Dimensions: ø300 mm
• Quantity: 4

Small Ribs: There are 16 right-angled triangles distributed around the circumference, reinforcing the structure and serving as a base for the flexible plywood covering.

• Material: 15mm Plywood
• Dimensions: Short Side: 60mm, Long Side: 440mm
• Quantity: 16

Covering panels: There are 4 sheets that, when combined, form a cone. They are made of flexible plywood to adapt to the circumference formed by the ribs.

• Material: 8mm Plywood Flex
• Dimensions: Detailed in the template
• Quantity: 4

BASE

Base Circle: This is the part that makes contact with the floor, and the large ribs are attached to it.

• Material: 15mm Plywood
• Dimensions: ø585 mm
• Quantity: 1

Middle Circle: This piece serves as a base for the connection blocks and keeps the large ribs securely in place.

• Material: 15mm Plywood
• Dimensions: ø320 mm
• Quantity: 1

Top Circle: This is the final piece that will make contact with the tabletop.

• Material: 15mm Plywood
• Dimensions: ø291 mm
• Quantity: 1

Connection Blocks: There are 4 solid wood blocks with a hole in the center to accommodate the 5/16 screw and washer, and another 4 blocks without holes that reinforce the structure.

• Material: 15mm Plywood
• Dimensions: 50x50x50 mm
• Quantity: 8

Large Ribs: There are 8 right-angled trapezoids distributed around the circumference, reinforcing the structure and serving as support for the entire table.

• Material: 15mm Plywood
• Dimensions: Short Side: 80mm, Long Side: 210mm, Height: 585mm
• Quantity: 8

Covering panels: These are sheets similar to the previous ones.

• Material: 8mm Plywood Flex
• Dimensions: Detailed in the template
• Quantity: 4

This is the general plan, and as we progress, we will add some elements for reinforcement, but nothing that will alter these dimensions. Regarding the templates for the cones, I recommend replicating them on paper first and testing them on the actual model. This way, we can avoid errors and incorrect cuts.

First, we'll start by cutting out the main circle and the other 4 circles that make up the core. I used a jigsaw for this, then I refined the edges with a router and a simple guide that can be easily made and functions like a compass.

After completing this step, we will have the exact center marked on each circle. Now, before assembling these pieces, I recommend tracing the distribution of the ribs on the main circle. It will be easier to do this now because later on, the core will complicate it. Once this is done, we join the 4 small circles together with screws and glue, and then attach this group to the main circle.

Now it's time to cut the 16 triangles that will form the ribs. Then, one by one, we will carefully place them on each of the marks we previously made (I forgot to do this, and indeed, it was harder to draw those lines now). We use glue, the brad nailer to hold them in place and then reinforce from the other side.

With the structure ready, we can begin to cover it with the flexible plywood panels. Using the template, I cut out the shape in paper and verified that everything would fit correctly. In theory, these panels are joined at their ends at 4 out of the 16 ribs, closing the entire circumference. These ribs are the ones that need to be widened so that when two panels are joined, they have enough surface area to support themselves. For this reason, I added some plywood scraps at these joining points.

With this done, we can place the first panel, verify that it fits well, add glue, and use the necessary nails. We repeat this process for the other 3 panels. Now, one consideration: as these panels curve, they leave a small gap at their ends. As we place them, we must adjust the angle of that edge so that everything is well joined between panels.

Once all the panels are in place, we can use the guide to rectify the central circle, and with a flush trim bit, profile the outer circle.

Now we will set this piece aside for the time being.

Now, we will continue with the base structure by cutting the 8 large ribs and the 3 circles that compose it: the base, middle, and top circles. There's no change in the procedure for the ribs; it remains the same as before. However, there is a slight modification required for the circles. Since these circles are internal and are surrounded by the flexible panels, they cannot have right angles on their edges; they need to have an incline to fit properly.

I solved this by cutting and shaping the circles to the specified measurements and then beveled them using a dovetail router bit. It happened to be a coincidence, but that angle adapted very well to the cone's shape.

With these three circles ready, we can start assembling. Once again, the process is similar. I mark the location of each rib on the base and middle circles and secure each of these pieces in place. After fixing them with glue and nails, I also add some screws at both ends to provide additional reinforcement.

After joining the base pieces, I thought it might need a bit more stability. So, I quickly cut these small trapezoids to fit between the ribs.

Now it's time for the system that will allow the table to be separated and joined as needed. These connection blocks are essentially cubes that will accommodate the bolt, which will grip onto the L brackets anchored to the top part.

I made these cubes from hardwood, and they have a through 5/16" hole. On one face, they have another hole of a larger diameter to insert a washer. There are 8 cubes in total, 4 with holes and the other 4 without holes. They are placed on the middle circle following the same distribution as the large ribs, alternating one with the other.

These cubes must be securely fastened as they are an important part of the entire structure. Then, the last circle is fixed on top of these cubes, closing the entire skeleton of the base. Next, a new concentric circle is cut into this piece to create a ring. This way, the top part will have a place to rest, and it will also allow the L brackets to connect with the blocks.

It's worth noting that since the cubes are positioned between two circles, they need to have the same angle on one of their faces as mentioned earlier.

A preview so far.

Now it's time for the flexible panels for the base. The procedure is the same, but this time, when creating the template, you need to add a mark to indicate the position of the bolt. I didn't include this detail in the .dxf file because it's safer to trace its location using the physical model. With this ready, we can verify that everything fits correctly and cut the 4 parts.

A detail to note is that I made a mistake when attaching the connection blocks. Without realizing it, I positioned them offset from the large ribs, which is why I couldn't make the hole in the center of the panel as I had originally intended.

Subsequently, we will make small covers to conceal that hole. The idea is for these covers to be magnetic and easily removable when you want to disassemble the table.

Now, with glue and more nails, it's ready to go.

We continue with the fastening system. Previously, I mentioned the optional use of a welder. This depends on the L brackets you can obtain. If you choose not to use a welder, you can create threaded holes in these pieces for the screw. In this case, the thickness of the piece will need to be sufficient to hold it firmly.

Since I couldn't find brackets of the required thickness, I decided to make them from scratch. I cut 4 pieces from a 2" plate, bent them at a 90º, and drilled 4 holes to attach them to the core, using the positions of the connection blocks as a guide.

For now, I haven't drilled the 5/16" hole for the screw yet. When precise holes are needed, I find it better to mark their position with the assembled object (of course, whenever this is possible). So, I assembled the base and top and marked the positions of the 4 holes from the connection blocks. I did this using the same 5/16" drill bit and applying some paint to one end to make it collide with the L bracket.

Then, with the marks in place, I drilled the holes and welded a nut to each one. Once again, the placement is slightly off-center, but it works.

A simple step, there are 4 small squares that fit in the space we left previously, and to hold on they have a small magnet in the center to match the head of the screw.

The table is almost ready; well, it's time to glue the decorative top with enough glue. I did this, leaving approximately 1 cm around the entire diameter, and then used the flush trim bit to profile the entire circle. Now you can look for something to cover the edge. I used some thin wood sheets that I had on hand.

Now it's time to sand any rough areas, smooth the edges, fix any imperfections, and apply the finish of your choice.

And that's it; everything is finished. I was genuinely surprised by how it turned out in the end, and I'm very pleased with it.

I hope this project can be useful to you. Thank you!