Tool help! I need to do specific angle miters!


#1

Hey all!
I’m in need of some suggestions. Tonight I tried to make a solid wood icosahedron (d20) out of an inch cubed piece of bloodwood. My first mistake was choosing this wood. It is super tough to work with because it is so hard and the sap burns so easily.

I started with this:

And ended with this:

It isn’t pretty, accurate or easy to do but I was working with the tools I had. The process is actually pretty simple. Its taking off corners at 21 degree angles.

I basically used this hand miter saw to start the cuts and then got frustrated and tried to finish it on the belt sander

Ideally what I would need is a saw exactly like that but like a half to a quarter of the size. That’s where you folks come in. I need suggestions! Have any of you seen something like this that might help me out?
What I would like to do is do up a little jig so I can bang out a bunch of dice in my spare time when I want to get away from my computer.

Just as a quick edit: I don’t need to follow this route. If anyone has an idea of how I can do accurate cuts like in a different way please let me know! This is totally a learning experience.


I don't need no 3D Printer?
#2

If you have access to a 3D printer or maker space, you could custom print a mini miter box with slots at 21 degrees.


#3

I DO have access to a 3D printer! That is a good idea!


#4

These are my favorite saws for super accurate cuts on small stuff:


#5

file this under things i never knew i wanted


#6

I agree with @hansena. You might also look at dovetail saws.


#7

Awfully specific, but I just mocked up a jig for doing d20s!


#8

Awesome :sunglasses:


#9

That’s funny, I was just thinking about how I could make some custom dice. Interesting conversation :smile:


#10

Might as well spread the info around!
Here are the instructions I followed! https://vonholdt.wordpress.com/2015/02/21/how-to-make-a-solid-twenty-sided-die/

I wonder how easy it would be to make a set of die using lasers and jigs to hold the piece at the right angle!


#11

I hear good things about these mini table saws

http://www.tylertool.com/rockwell-rk7323-portable-tabletop-saw/rkwnrk7323,default,pd.html?ref=pla&zmam=31282435&zmas=47&zmac=723&zmap=rkwnrk7323&gclid=Cj0KEQiAtK3DBRCBxt-Yxduq5p4BEiQAbFiaPedA_Eu_I_i2kvvQlYR96VX5N6uehOf4JVP87MvObqIaAotv8P8HAQ


#12

If/since all the cuts are 21º, a band saw with a tilting table might work well.


#13

i was thinking of a band saw too, with the right jig.


#14

I think your die looks pretty good, myself. :slight_smile:

I modeled the shape as shown in the Von Holdt blog, but it’s not quite a perfect icosahedron. 21º is pretty close, but it looks like 20.9º would be a better number to shoot for if you’re using a digital protractor to set up whatever machine you end up using.

For confirmation of this number, here’s a Wikipedia table of polyhedron dihedral angles…

For ultimate precision…

Using the formula from the Wikipedia page Wolfram Alpha says it’s “2.411864997362826875007846723466182188800663485327392130265” radians, which Google says is 138.18968510456420518º. 180º minus that, then divided by 2 is 20.9051574477º.


#15

I buy Japanese saws as a gift for new wood workers, but I often buy them from Garrett Wade, which is fairly expensive. The link you posted is for pretty cheap saws. Have you found that they hold up well over time?


#16

I’m using hand tools mostly and was having enough trouble with 21 degrees. Maybe when my glowforge comes I can set up a jig for more accurate cuts and use that!


#17

You should probably never, ever, ever go here.


#18

Hilarious. +20 experience for creating it though!


#19

I don’t suppose I could ask you to share the file for this?


#20

hnnnnng