Folding C Table

I made this table because I couldn't find one that suited me in stores. It was made with four goals in mind:

- To fit the dimensions of our huge U-shaped sofa.

- To be able to use it with my favourite Poang lounge chair.

- To be made entirely from leftover hardwood.

- And most importantly, to be out of the way when I don't need it.

- Tajima kataba 265 fine (optional)

- Fretsaw - Chisel 6 mm (optional)

- Saw guide - Table saw (optional)

- Table saw or miter saw

- Hand router

- Ø 20 mm round nose bits

- Ø 18 mm drill bit

- Rabbeting Bit (optional)

- V-Grooving Bit (optional)

- Drill press

- Bar clamp

- Wood glue

- 704×50×20 millimeters, 2 pieces (in the drawings light green)

- 788×50×20 millimeters, 2 pieces (in the drawings light blue)

- 400×60×20 millimeters, 2 pieces (in the drawings dark green)

- 400×60×20 millimeters, 2 pieces (in the drawings dark blue)

- 400×9×7 millimeters, 3 pieces (in the drawings dark green, dark blue)

- 72×49×400 millimeters, 1 piece (in the drawings dark blue)

- 800×74×20 millimeters, 2 pieces (in the drawings red)

- 400×9×7 millimeters, 3 pieces (in the drawings dark green, dark blue)

- 400×45×11 millimeters, 1 piece (in the drawings dark blue)

- Ø 20 millimeters, length 420 millimeters, 4 piece (yellow in the drawings)

I created this guide so that you, dear reader, can make a table of the right size for your needs. My English is poor, so please forgive me if I use the wrong words!

- Step 01. On the work plane, we place a box (red) with a side length equal to the thickness of the chosen tabletop. On the right and left sides of the box, we place a cylinder (ochre) with a diameter equal to the thickness of the chosen rod.

- Step 02. We select the shapes in groups and rotate them by 45 degrees.

- Step 03. We select the box and rotate it back by 45 degrees.

- Step 04. We select the box, duplicate it and repeat. We change the size of the copy to the width of the tabletop. We change the color of the original box to blue. We select the red and blue boxes as a group, and align the red box to the center of the blue box.

- Step 05. We select the cylinders as a group, duplicate and repeat. We change the copy to a hole, and assign the red box to the group using the shift key.

- Step 06. We group the selected shapes.

- Step 07. We select the shapes as a group, and rotate them by 90 degrees.

- Step 08. We get this group, whose group selection is not canceled.

- Step 09. We move this group down, set the lateral displacement to zero with the keys. The amount of downward movement is determined by the length of the table top.

- Step 10. - We select the lower shapes as a group, look at the width of the group. From this, we subtract the thickness of the cylinder. With the result obtained, we move the group to the right. (Enter the value with the key!)

- Step 11. The two cylinders in the picture should be in the same line. By turning on the alignment, we see that this is not the case. If we check the width of the group of cylinders, we can see that it is the same as the diameter of the cylinder. So they are in the same line.

- Step 12. The further steps are as simple as a pallet.

I made the parts 800 millimeters long so that I could correct any errors. According to the dimensions of the plans, I drew the positions of the Ø 18 millimeters blind holes using a caliper. The distance between the centers of the holes should be 40+ millimeters. I made the blind holes. The finished size of the legs from tip to tip is about 795 millimeters. They are inclined forward at 1.5 degrees, which means a 2 millimeters slope at a width of 74 millimeters. I made these cuts during the final assembly, so I didn’t deal with them now. I shaped the ends of the Ø 20 millimeters rods to Ø 18 millimeters at a length of about 9 millimeters with a table saw. I assembled the plinth frame dry and secured it with bar clamps. This way I could check that the frame parts slide smoothly between the Ø 20 mm bars. (If the thickness is not correct, you can correct it now.)

On the 400×60×20 millimeters (dark green in the drawings) parts, I drew the round groove lines according to the dimensions of the plans. I put a V-groove bit in the router. I aligned the tip of the bit on the line and secured the fence to the edge of the part. I replaced the V-groove bit with a Ø 20 millimeters round nose bit and created the round grooves. I made the inner curve necessary for operation with sandpaper. (Do not adjust the router fence, you will need it later!)

I connected the frame with an open tennon. This joint provides adequate strength. I cut 50×7 millimeter mortises on the ends of the 400×60×20 millimeter parts with a table saw. On the 704×50×20 millimeters (light green in the drawings) parts, I cut 60×7 millimeters tenons on the ends. I dry-assembled the frame and secured it with bar clamps. I used a wood router with a rabbeting bit to make a rabbet on the top, inner edges of the frame. The table top parts are ready. You can make it from edge-glued board, but I have other ideas for the future.

I designed the 400 millimeter (dark blue in the drawings) and the 788×50×20 millimeter (light blue in the drawings) parts in the same way as the upper frame.

I inserted the lower and upper frames between the bars of the plinth frame. I checked that the round grooves and the bars fit properly. I corrected the errors with a Ø 19 mm bar and sandpaper.

I glued the 400×9×7 millimeter slats to the 400 millimeter parts (dark green in the drawings). These slats prevent the upper frame from slipping out of the plinth frame. I glued the upper frame together. I aligned the slats to the round grooves with a hand router. I made a board out of plywood that fits into the rabbets on the inside edges.

I glued the 400×9×7 millimeter slat to the rear 400 millimeter part (dark blue in the drawings). I cut a 6×7 millimeter groove on the long edge of the front 400 millimeter part (dark blue in the drawings). I shaped the cross-section of the 400×45×11 millimeter part (leg) according to the dimensions in the drawing above. (During the last test, I adjusted the table horizontally by changing the size of the leg.) I glued the lower frame together. I aligned the slat and leg to the round grooves with a hand router.

I fitted the lower and upper frames between the plinth frame bars. I dry-fitted the plinth frame and secured it with bar clamps. I folded the table and marked the cut points on the 800mm leg. I opened the table and set it level. I marked the cut lines using the marked points.

The finished size of the legs from tip to tip is approximately 795 millimeters. They are angled forward at 1.5 degrees, which is a 2 millimeter slope for a 74 millimeter width. I made the cuts mentioned in the “The Legs” section of the guide. The Tinkercad plans are for reference only. I intentionally made the round grooves smaller so that I could make precise joints during final assembly. So I sanded and tried a lot, and sanded and tried some more. The glued-on leg and the slats had to be completely reshaped because they were tighten a lot of strain on the structure.

I described the design considerations in the introduction. Unfortunately, one of these, “To fit the dimensions of our huge U-shaped sofa,” was not fulfilled. The sofa leg is 5 millimeters higher than the table’s, but unfortunately I can’t push it under. The reason for this is that the bottom of the sofa’s storage is very humpbacked. That’s why I cut off the front leg of the table. Unfortunately, I still couldn’t push it under completely. (I’ll glue the leg back on later. I’m looking for a suitable sofa so I can take pictures.)

The table is made of Ash wood, which is very strong and flexible. Nevertheless, it noticeably bends forward when loaded with 5-6 kilograms. Its relatively large size may play a role in this. Perhaps it would be more practical to make it out of metal.