This tensegrity table is made out of mahogany and African padauk, with paracord for the strings. I used a strong hand-cut tapered sliding dovetail joint to attach the upright to the base and splines in each corner of the base for strength. You can find plans for the tensegrity table here.
Marking out the Tensegrity Table Base
I drew two large triangles on the mahogany board. Then I divided the triangle in half from each corner. And drew curves by placing nails in the board and bending a straightedge and tracing it.
Cutting the Sliding Dovetail Mortise
I marked out the sliding dovetail on each straight end of the triangle. Then I made a guide block beveled at 7°, clamped it to the board, and pressed my kataba saw* against it to cut the walls of the mortise.
Then I chiseled out the waste and used a Stanley 71 1/2 router plane. See this video to learn how to sharpen a router plane.
Making the Support Arms
Using the SketchUp model, I created a template for the support arms and traced it onto the padauk piece twice. I made sure to orient the long grains on the longest part of the arms for strength.
Cutting the Dovetail End of the Sliding Dovetail
On the support arm, I made a knife wall and sawed a shoulder, then stacked the two support arm pieces and used the same guide block I used earlier to chisel a 7° sliding dovetail that matches the mortise in the base.
I intentionally tapered the mortise of the sliding dovetail joint, so after cutting the initial dovetail angle on the support arms, I tapered it slightly to match the angle.
With a little bit of wax on the joint, it slid together very tightly. The taper allows you to achieve a very tight fit on the sliding dovetail with no glue or fasteners.
Reinforcing the Base with Splines
To reinforce the corners against splitting, I added two splines to each corner of the base. Notice that on the leftmost spline in this illustration, the grain is perpendicular to how the other splines were cut. This is necessary to get strength out of that corner, because if the grain of the spline were parallel with the grain of the corner, it would not add strength against splitting.
I used a tenoning jig on the table saw to cut kerfs into the base, and then I glued the splines in place. Pictured is the corner with the perpendicularly cut splines.
I cut off the excess from the splines and then sanded the edges of the base with a belt sander to smooth it.
Attaching the Cords to the Table
Using gouges, I carved a groove into spine of the support arm to hold the paracord. With some test fitting, I got the cord to fit snugly in the groove.
On the end part of the support arm, I used a file instead of a carving tool.
I drilled through each corner of the base using the drill press. This goes through both of the splines I added earlier.
I used a hand plane in a vise to cut tapers to the ends of some dowels. I made 6 with a double taper and 6 with a single taper.
For safe usage of a hand plane on small parts, see my video Working Small Parts with a Hand Plane.
I drilled a hole into the support arm and hammered in one of the single-tapered pegs to lock the paracord in place. I oriented the taper against the cord, so the dowel pinches it as it gets driven in.
I drove a dowel lightly into the second support arm, which I hung from the first one to test the length of the cord. Once I was happy with how it looked, I drove that dowel in tightly to lock it in place.
On the corners of the base, I put in the ends of two cords and drove in a double-tapered dowel to secure both of them to the base. This operation would split the corners of the base if they weren’t reinforced with splines.
Assembling the Table
Then I hammered the sliding dovetails together to attach the support arms to the bases of the table.
I made three support blocks out of scrap wood to hold up the top and I fed the cords through the holes in the top piece.
Fine-tuning the Tension on the Table
I lightly hammered the double-tapered dowels into the top to hold the cords in place. Then I placed a level on the table and pulled each cord tight one at a time to fine-tune the tension of the table. Once the table was level and the cords were tight, I drove the pegs in all the way to lock everything in place.
This tensegrity table is very stable, possibly because I used six outer cords instead of three which is common. I didn’t test how much weight it holds, but the paracord is quite strong. Other than that, a potential point of failure would be the dowels slipping out, but they are very tight so I doubt that would happen. They can be glued in place if you are concerned about them slipping out.
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