Tetra Table

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Introduction: Tetra Table

About: Interdisciplinary Artist

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!

Step 1: Table Top Design

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.

Step 2: Mahogany Interior Triangles

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.

Step 3: Purple Heart Triangle Edge and Mahogany Pieces

Cut w/Table Saw Jig

Step 4: Ratchet Strap for Setting/Gluing.

Step 5: Table Base Design

Truncated Tetrahedron

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

Step 6: Adding Thickness

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

Step 7: Tablesaw Jig Design for Mitre Cuts

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.

Step 8: Cut File

W/Jigs included

Step 9: Laser Cut Forms and Jig Pieces From 3/4" Birch

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

Step 10: Sanding Laser-Burnt Edges Off

Step 11: Jig Assembly

Cross members made from 1/2" ply.

Step 12: Cut Mitres With Table Saw Jigs

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.

Step 13: Finished Mitre Cuts

Fresh cuts

Step 14: Measure Interior Angle With Laser-Cut Angle Template

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.

Step 15: Cutting, Breaking/Bending

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.

Step 16: Drill Holes, Countersink Brackets

In the metal shop at Pier9

Step 17: Pre-drill Holes, and Attach Brackets W/Wood Screws

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

Step 18: Bracketed Panel Assembly

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

Step 19: Base Assembly Finished

Step 20: Sanding Down Tabletop

Lots of dust.

Step 21: Mitre Tabletop Edges

One last finishing move.

Step 22: Assembly

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

Step 23: Finishing W/Beeswax

Non-toxic, orange oil and beeswax.

Step 24: Complete

Thanks for looking!

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    21 Comments

    grrrrrrr its suuuuper cooooool!!!!
    im going to try this one. thanks for this guide :)

    This and your other Instructables are Mind Blowing man !

    You are an artistic Genius sir.

    If you were closer I would love to meet you & study under you.

    Thank you.

    I really like how you took the time to mock up your tablesaw jigs in the software. That's some intense planning.

    1 reply

    Yeah a bit over the top. I eventually want to make a mitre jig with adjustable knobs, and this was sort of a test. Of course, now that I have access to the 5-axis Waterjet at Pier9, it's almost moot. :)

    I LOVE IT! How big is it? like in terms of height and length, I was wondering if you could share the Rhino file you made or the cut file I am planning on making this as a housewarming gift for a friend. Much appreciated.

    1 reply

    Hi Mahaa1,
    My final design is 16" in height, and ~40" wide from tip-to-tip.
    I updated the Step 1 by uploading my Rhino file.
    Thanks for looking!

    It's pretty heavy! I'd say the top is about 20lbs or so, and then base is even heavier, including the brackets. Thanks for looking!

    I wanted to make one for my mother, but cleaning days could be a problem. Anyway cool table, keep sharing with us wonderful projects like this one :-)

    Great looking table! I love the types of wood you used.

    Great work, thank you

    user

    Nice, I like it.

    excellent model for creativity . i like it

    awesome concept, and work.

    Wow! That turned out great! I love seeing beautiful wood pieces like this!