CAD a D8
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Supplies
CAD Software, I use OnShape as it is free
Make a Square
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- Make a Square whose center is on the origin and the points are on the axis of the other planes
- Add your one dimension to say how big the square is
- Add a construction line from the constrained point down along the "Right" plane
- Make the construction line be equal (same length as) the side of the square
Find the Top and the Bottom
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- Make a construction circle whose radius is the height of the square
- Make two construction lines from one point to the edge of the circle
- The lines should end on the front plane, above and below the origin
Loft
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- Loft the base square to both the top and the bottom points found
Finish!
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You now have a "blank" D8!
Feel free to add numbers to it or whatever else you want!