How do I make bevel cuts to form a ring with 2x4's?

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    Are you asking what formula calculates the angles or what software Michael Karas used to make the picture?
    – fixer1234
    Jul 20 '17 at 4:45
  • I only now realized that this particular post has one question in the title and a completely different question in the body. I answered the question in the body, obviously. The question in the title might belong in the Software Recommendations SE, yes?
    – fred_dot_u
    Jul 20 '17 at 18:14
  • "what program did you use?" ... meat Jul 21 '17 at 10:06

The number of facets (sides) for your ring will determine how to perform the cuts necessary to make the ring.

For example, one can consider a square formed from 2x4s to be a ring. Each cut would be half of the 90° angle at the corners, or 45° set on the miter saw.

Jumping to double the above, a 22.5° cut on eight pieces will give you an octagon, 11.25° will give you a sixteen facet ring.

If threes are your thing, a triangle needs 30° cuts to make the 60° joining, while a hexagon with 120° angles will magically appear when your cuts are 60° on the saw.

Going another step to 12 sides means a cut at 75°, or 15° from square to the end.

The math is pretty simple.

360 divided by number of sides = interior angle. interior angle divided by 2 = cutting angle.

Be aware that it's important to track which side of the lumber is "outside" as flipping the wood incorrectly will result in a parallelogram instead of a trapezoid.

  • I chuckled at your final suggestion. A person is smoking something pretty good to make that mistake (and probably shouldn't be operating power tools).
    – isherwood
    Jul 20 '17 at 0:34
  • I'm not a smoker, but have managed to pay attention insufficiently enough to have to recalculate my stock supply for a specific project on occasion and/or purchase more.
    – fred_dot_u
    Jul 20 '17 at 0:58

This would depend on what size of a ring, as well as how round you want it to be. Shorter pieces of wood, cut at smaller angles, would give you a more round ring, longer pieces of wood at a greater angle would give you a less round ring. Changing the angle would change the size of the ring as well as the roundness.

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