Here is how I made our new 60" (152cm) round dining table that has a 24" (61cm) diameter turntable so everyone has easy access to the dishes. It's large enough to seat 8 comfortably. I wanted to have a natural wood look.
The top is removable (it is heavy, about 80 lbs/36 kg) and sits in place under it's own weight. A wooden dowel pin is used to center it on the base and cork pads on the top of each leg ensure accidental bumps will not shift it. The turntable sits on top of the main table and can be removed if needed.
Step 1: The Design
The table was built in 3 parts as shown in the figure on the left. The turntable has the Lazy Susan Bearing embedded in its underside and simply sits on the main table. Both the turntable and the main table were made from 1-1/4" thick stock and the lower edge on both was beveled with a 15 degree low angle bevel bit in a router table.
The base is made from 4 posts (3-1/4" square, 28" tall) and held together with mortise and tenon joints. In addition, dowel pins were added to further secure the mortises. I used maple dowel pins and left them about 3/8" recessed. I then cut plugs from some left over walnut to give them pins a decorative look. An 8" square plate (with dadoes for the cross members) is used to ensure the assembly is square. It also has the 1/2" dowel in its center that is used to align the table top with the base. As the base is only 28" high, it can be turned sideways and carried though any door opening.
Most of my measurements are shown in imperial units, but my drawings have metric on them as well. Lumber here is supplied in imperial measurements and it is much easier to buy router bits and other cutting tools in imperial sizes than metric ones despite the fact Canada is "all" metric.
Step 2: Tools and Materials
- Safety first: Ear muffs, safety glasses and a dust mask are a must. Gloves might be useful as well.
- Table Saw
- Mitre Saw
- Biscuit Joiner (optional)
- Drill Press
- Random Orbit Sander
- Belt Sander
- Router bits (long straight bit, edge profiling bits as )
- Clamps (bar clamps, pipe clamps, ...)
- Drill bits (especially a 1" Forstner bit for the mortises)
- 1/2" wood plug cutter
- Measuring tape, rulers, squares, marking tools
- PVA Glue (I used Titebond II)
- Sandpaper ranging from from 80 to 220 grit
- Light (maple coloured) wood filler
- Brushes for finish coating
Both the table top and the turntable were made from 1-1/4" thick eastern maple. I wanted a sturdy top and it was more economical to use cut-offs from the main table top (buying longer pieces) to make the turntable than having some boards custom milled to 1" thick for example. Widths and thickness are given in sizes typically available in North American supply stores.
- Table Top (1 1/4" thick)
- 3 pieces 62" long x 7.25" wide
- 2 pieces 58" long x 7.25" wide
- 2 pieces 49" long x 7.25" wide
- 2 pieces 31" long x 5.5" wide
- Turntable (1 1/4" thick)
- 2 pieces 26" long x 7.25" wide
- 2 pieces 26" long x 5.5" wide
- 8 pieces 29" long x 3.5" wide x 1.25" thick
- 4 pieces 29" long x 3.5" wide x 3/4" thick
- 1 piece 8" square, 3/4" thick
- Upper: 2 pieces 30" long x 2.5" wide x 1.25" thick
- Lower: 2 pieces 30" long x 3.5" wide x 1.25" thick
- 1 piece 8" square x 3/4" thick for the upper cross member brace plate
- A 48" length of 1/2" dowel to pin the tenons and some walnut for making decorative plugs
Step 3: Making the Turntable
The 4 pieces for the turntable were glued together as shown in the first image. I used a biscuit joiner primarily for alignment and it is entirely optional. As it is not uncommon for glued up tops to want to buckle a bit while being clamped, I used 1" square aluminum tubes clamped to either side to keep the glue-up flat. You can also use some sturdy wood stock and wrap it in wax paper or plastic wrap to keep the glue from sticking to it.
While the glue was drying, I made two trammels to cut the circles. I used 1/2" plywood cut to the width of my router and marked the holes for the mounting screws. After mounting the router, I installed a v-groove bit and used it to mark the router bit center on the plywood by plunging the router down (without power). I then laid out the 1/2" measurement grid on the plywood and once that was done, used a hole saw to cut a clearance hole for the router bit. There are many types of circle cutting jigs out there, this simple style works for what I wanted to do. I could have made just one trammel and used it for both the turntable and large table, but it would have been cumbersome to have a 32" long trammel swinging around a 24" table.
I cut the circle for the turn table with a 1/2" diameter 2 1/2" long bit in 6 passes (about 1/4" cut per pass). I then marked the bearing on the bottom side and used the trammel to cut a 3/8" deep recess. Once done, I used a 15 degree low angle bevel bit to reduce the thickness of the lower edge and a 1/8" rounder over bit to remove the sharp edge from the top.
Finally, I sanded the edge first with a belt sander and 80 grit paper by laying the sander on it's side and spinning the turntable against the running belt sander. I did not used the Lazy Susan bearing to do this, as I wanted to keep it dust free. I placed the turntable on a small nail (head cut off) in my work stand and spun it on that. I followed up with a random orbit sander to remove any other marks.
Step 4: Making the Base - Part 1
Each leg was glued up from 2 pieces of 1-1/4" thick and one piece of 3/4" thick stock, 3-1/2" wide and about 29" long. Once the glue had dried, the legs were trimmed to 28" length and 3-1/4" wide (to make them square). The centers were marked and the 1" wide mortises laid out.
The mortises were drilled to a depth of 2" on a drill press using a 1" Forstner bit. I started with the mortises for the upper cross members. I set a stop on my drill press fence and drill the outer end of the mortise for each leg. Then I reset the stop and drilled the other end for each leg. This ensured that all legs have the exact same length of mortise. I then drilled over lapping holes to remove as much material as possible and chiseled out the remainder. I left the ends round, since I had planned to round over the tenons. I repeated the process for the lower cross member mortises.
As noted in the drawings, I did not drill the holes for the dowel pins yet. Those will be drilled once the base is assembled and that will ensure they line up with the holes in the tenons.
Step 5: Making the Base - Part 2
The cross members were joined with half-lap joints. I cut the dadoes for these using the table saw, since my router table doesn't allow me to cut to the center of a 30" long work piece. I used a stacked dado set to make the cuts, but set it up with just the two outer blades and one chipper. This is much narrower than the dado to be cut, but the technique I used makes use of this. The dadoes should technically be 1.25" wide, but there is also some variation even in precision milled hardwood lumber. The upper cross member stock and the lower cross member stock each came from one length of lumber to ensure they had the same width.
I marked the approximate center and depth (1.25" for upper and 1.75" for lower) on each piece with a pencil. I then set up my table saw miter fence with a stop set near the center of the work piece. I set the cutting depth to about 3/8". I then took a cut, flipped the piece around and cut it the other way as well. This ensured the dado would be centered. I then moved the stop slightly towards the blade and repeated the process until the two pieces fit snugly. Then I marked the stop on my fence with a small block so I had the width of the dado saved. I could then move the stop back to the starting position to cut the from the center of the dado and return to the outer edge. Then I raised the blade in steps, repeating the process of flipped the piece end to end until to two cross members mated flush. The process was repeated for the lower cross members and since they were the same length (and thickness), the width of the dado was already set on the fence.
Step 6: Making the Base - Part 3
The tenons on the cross members were cut on the router table in several passes. The corners rounded over using a chisel after cutting on the corners to avoid tear out. A strip belt sander was used to smooth them while test fitting. After I was done this, I remembered I had a 1/2" round over bit ...
The dadoes for the brace plate were cut on the router table by turning the piece around and making several passes of light cuts until it fit snugly.
The legs had the edges rounded over with an 1/8" (3.175mm) round over bit on the router table and the bottom of each leg was chamfered with on the table saw (about 1/2" or 12.7mm).
Step 7: Assembling the Base
First the base was test fit on a flat section of the garage floor. Then it was glued and clamped for 24 hours. After the clamps were removed, the excess glue was either chiseled or scraped away with a cabinet scraper.
The dowel holes were drilled with a 1/2" (12.7mm) spade bit since the Forstner bit was not long enough to reach through the 3 1/4" wide legs. A backing board was clamped in place to avoid tear-out. It would have been a challenge to drill from both sides of the leg and have the holes line up well enough for the dowel to fit in.
The 1/2" diameter dowels were cut about 2 1/4" long so they would remain recessed below the surface of the legs. The dowel holes were then filled with plugs cut from some scrap walnut. The plug cutter makes taper plugs, so they fit nice and snug. Once the glue dried, the excess plug material was chiseled off and the entire base sanded to 220 grit starting with 80 grit.
Step 8: Making the Top
The top is made from 9 maple planks, so they were edge glued in sets of 3 to make the task more manageable. I used 5 biscuits in the longer planks to help align the surfaces (3 in the short outer ones). First the center section comprised of 3 (62" long) planks was glued up, then the outer two sets (58", 50" & 34" planks) were glued up and finally the 3 sets were glued up. Dealing with only two glue joints at a time made the task easier, as the weather here was quite dry at the time and the glue had less than 15 min of open time. Since I did not have clamping cauls long enough for the entire top, I weighted down the center with whatever was nearby (about 100lbs/45.4kg). I checked for flatness as I added the weights.
The longer trammel was set up just as the shorter one was for the turntable and the round top was cut out in about 8 passes. The lower edge was bevel cut to match the turntable and a 1/2" (12.7mm) round over bit was used on the upper edge. A 1/2" diameter hole was drilled 3/4" (19.05mm) deep in the bottom center to receive the alignment dowel.
The glue was scraped and sanded away and finally the entire table was sanded to 220 grit from 80 grit with a random orbit sander. Finally, I handed sanded the entire table top along the grain with 320 grit to ready it for finishing.
Step 9: Finishing
The base was coated in 6 thin coats of high gloss Varathane, sanding between each coat. The turntable received 5 coats of Varathane (sanding between coats), since it was likely going to see more wear and tear.
Drilling large diameter recesses into the end grain proved to be a bit difficult. Instead, I cut out 4 cork pads (roughly 2"/50mm square and 1/8"/3.175mm thick) to set the table on the legs. These would mostly flatten over time from the weight of the table top and not be noticeable.
The table top was finished with 3 coats of high gloss Varathane on the bottom and 4 coats on top, always sanding between coats.
Step 10: Final Notes
An acrylic cover was added to the turntable tap just to reduce damage from spills, etc. That is totally optional and maybe a round place mat would be just as good (which I might make anyway).
One thing I would do different if I had to do this again, would be to buy a jointer ( I have a planer) and work from rough lumber. I would have had much better control over the quality of the stock.