Making 20 sided Dice?

Perfect reason to invest in a CNC machine.

lol Loren, yes well, CNC’s are just a bit out of my price range. o.k., more than a bit.

-- Adventure? Heh! Excitement? Heh! A Woodworker craves not these things!

Woodspanker – What you are considering is called an icosahedron. You can find a lot of information about these geometric figures at http://en.wikipedia.org/wiki/Icosahedron. This website portrays many of the angles that you will need in making the item that you are considering. If you are versed in geometry and a little trigonometry you should be able to determine the cutting angles. This polyhedron has 20 identical equilateral triangular faces, 30 edges and 12 vertices. I have made these as wooden plant holders but never a die. If I can be of further assistance please feel free to contact me.

-- Roger M, Aiken, SC

I just looked at that page and and it looks like you have a tall order on your hands. Good luck.

helluvawreck
https://woodworkingexpo.wordpress.com

-- If a man does not keep pace with his companions, perhaps it is because he hears a different drummer. Let him step to the music which he hears, however measured or far away. Henry David Thoreau

I know it is not the same thing but this might give you a starting point-
http://www.magicalwoodproducts.com/dodecahedron.html

-- Lew- Time traveler. Purveyor of the world's finest custom rolling pins!

I think perhaps the easiest way to make a one-off in a small
size would be to make a sphere, plot out the intersections
on the surface, and use a chisel to make a flat between each
set of 3 points.

That does look tricky. What size does it need to be?

Looking at the animation that RogerM pointed to, it looks as though you could start this on a lathe (you’d probably need to have a chuck). There are ten triangles around the outside of a cylinder and then each end has five triangles meeting at a point. So if you started with a cylinder that has a cone on each end you would, as suggested above, need to mark the vertices and then either chisel or file the faces flat.

-- I may have lost my marbles, but I still have my love of woodworking

I will be keeping an eye on this conversation. My 9-year old is very much into D&D. When he saw this, he said, “I think that some numbers will come up more often than others”. Which is a good point. Since this is not just something to look at, it is not enough that the dice look regular. They have to be regular in many subtle details such as the rounding of the edges.

I hope you are able to find a solution.

-- "Too much hurry ruins the body. I'll sit easy … fan the spark" - I. Anderson

This may be a stupid idea, but why not cut out 20 equilateral triangles from a thin board, miter the edges, and assemble them?

Or alternatively, using the net from http://en.wikipedia.org/wiki/Icosahedron, trace the pattern on a thin piece of wood. Go over the edges with a chamfer bit just far enough to let the wood fold, but not through. Then fold the net onto itself to create the icosahedron…

-- "I suggest a new strategy, R2: let the Wookiee win."

Thank you all for the wonderful Ideas! I shall have to try them all until I find the solution. (on pine, of course). SO far, Nick85’s idea sounds like the best… though glue up might be a bit of a problem. IF it works, however, then it is GOLDEN! :) I will have to figure out something to fill the empty middle with, so that the dice have some heft to them.

-- Adventure? Heh! Excitement? Heh! A Woodworker craves not these things!

epoxy?

-- Always one more tool away from being an excellent woodworker...

Would it be cheating if you laminated over an official D&D die? xD

I think if I were to do it, I would assemble 19 faces, and before placing the 20th, fill the cavity with epoxy or resin (although depending on the size and thickness of the wood, resin may heat up too much and warp the figure.) After placing the last face on, add the numbers, and dip the die in some high-build crystal-clear epoxy. Just keep twirling it around like you’re at a rave so you don’t get any runs…

-- "I suggest a new strategy, R2: let the Wookiee win."

I’d look into using a combination of Martin’s EZ Mitre Technique and Nick85’s triangles. Route out the numbers while the board is still flat. You’ll need a few jigs and a very accurate saw. Looks like a fun project. -Jack

I did some fiddling on Sketchup and came up with the interrior angle between adjacent surfaces being approximately 140°. So a standard 45° v-groove bit will take off too much wood from the edge. That may mean that you need to use an epoxy or other glue that fills gaps rather than a pva type glue.

-- I may have lost my marbles, but I still have my love of woodworking

epoxy and pre cut triangles it is. Thanks all, I’ll let you know how it turns out.

-- Adventure? Heh! Excitement? Heh! A Woodworker craves not these things!