Tetra Table

Tabletop:

• Inner Triangles: Mahogany
• Inner Triangle Edges: Purple Heart
• Outer Middle Parallelograms: Mahogany
• 3x Hexagon Edge: Walnut
• Outer Octagon: Red Oak

Table Base:

• 3/4" Birch Ply
• 1" Steel Bar Custom Brackets

Designed in Rhinoceros 3D

The concept for this tabletop came from a floor design for a geodesic dome. I wanted to geometrically transition from 3 (the triangle in the middle), to 8 (the octagon on the outside). I started by cutting shapes from scrap materials, and the project transformed into the following table design with a complimentary base. I consider the base a prototype, as I'd love to redo it in a nicer wood someday. If I were to build a similar design again, I would definitely consider attaching the table-top pieces with biscuits for added strength.

Enjoy!

No fancy code or algorithms used. The geometry is all designed by hand, using Rhino's snapping tools.

The Rhino (.3dm) file is attached if you want to explore the design, or make one yourself.

Cut w/Table Saw Jig.

Unfortunately I am lacking documentation in these first steps, as I was "in the zone". I essentially marked the angles on the stock, and used a custom table saw jig make my cuts.

Cut w/Table Saw Jig

Truncated Tetrahedron

Created by intersecting two tetrahedrons (3-sided pyramids), and removing the bottom with a boolean plane.

Using the 'extrude' tool, I thickened the pieces.

I measured the angles between the pieces with the Angle tool, and designed some mitre jigs explicitly for the form. I aligned the mitre-edge to the vertical table saw blade, and then engineered the jig to support the workpiece with clamps as it gets cut.

I could have also utilized the mitre-angle of the table saw, but it's more precise and less confusing to leave the blade at a vertical 90 deg.

W/Jigs included

Using the Metabeam at Pier9, cut from high quality 3/4" ply.

Cross members made from 1/2" ply.

I attached each piece to the jig after I labeled each edge so I would stay organized. I pushed each jig through the saw by hand after attaching the workpiece to the jig with clamps.

Fresh cuts

Angle calculated from CAD file, laser cut on an Epilog laser cutter at Pier9. There is only one angle to measure, which makes it easy.

Using the laser-cut angle template, I used the metal break to match the angle I needed.

Since the form is a tetrahedron, all the interior angles are identical.

In the metal shop at Pier9

A little piece of tape on the drill bit keeps from plunging too far.

I loved this part. It was satisfying knowing that I got the mitre cuts right.

Lots of dust.

One last finishing move.

Not Pictured: I added small walnut feet on the underside of the tabletop to keep it from shifting around.

Non-toxic, orange oil and beeswax.

Thanks for looking!