Paying attention to things on the ground

[monroe_the_fast]

I've been paying a ton of attention to things on the ground. I've found at least four hats in the last two weeks. One, I am wearing now, another is perfect for my nephew, with a T-rex chasing a triceratops, so I took it home and washed it. Left the other two. And I've found as many scarves. In the course of a day's walking I'm bound to find at

Comments

[biscuitboy]

It would be really cool if you could finish it. The reason the pieces don't fit together really well is because I cut the triangular faces with my dad's compound miter saw. The weight of the cutting assembly (I later noticed) caused it to deflect by maybe half a degree, so that what is supposed to be a 60 degree angle for the equilateral triangle actually may be 59.5 or 60.5-ish. This is probably fine for most woodworking, but when you are trying to make a 20-sided 3-D figure that folds together, accuracy seems to be more critical.

If you have access to a higher quality saw, you might be able to cut the pieces smaller and re-try. Or, if you don't care about having relief cuts on the interior of the icosahedron where the faces fold together, you wouldn't even need a compound saw. You could just focus on cutting the important angles (the 60s) more accurately, and have an icosahedron that has little "cracks" or "channels" at the joints when it is folded up. Either way, let me know how it goes.

I have Jizo on my dresser next to my little olive green tea candle holders. He looks very much at home and I like him a lot. I hope he is there for a long time.

[monroe_the_fast]

What is the angle of the bevel for the pieces? If you happen to know the angle at which I should bevel pentagons for a dodecahedron, that would be handy, too.

[biscuitboy]

http://en.wikipedia.org/wiki/Icosahedron

http://en.wikipedia.org/wiki/Dihedral_angle

I believe the angle you are asking about is referred to as the dihedral angle, or rather 90-minus-dihedral angle. It's in here. I'm sure you can figure it out from this.

[monroe_the_fast]

Gracias. Now I must overcome my fear of the table saw.

[biscuitboy]

No you mustn't. You should be afraid of table saws; they are fucking dangerous as all hell. Use a push stick, never reach over it while it's running, don't use the gate when cutting a piece across its short dimension (it can easily jam), and push the piece all the way through until it falls on the floor.

Do that, and you should be ok. :) Are there people there whom you can ask for help if need be?

[monroe_the_fast]

Yeah, there are, that's why I'm so afraid of the table saw. Scary stories. And already now I've sent two pieces of wood flying.