Laser-Cut, Filled Dice

projectinspo

#1

I picked up a laser-cut 6-sided die at a convention a few years ago. I always kicked myself for not buying more than one, but now I will be able to make my own. But I thought I would take it one step further. When I had my 3D printer I looked into (briefly) cold-casting with metal infused resin to make things, but I never got around to doing it. My idea then, is to make a D6 out of thin ply (1/8"), construct the die, then fill the interior with metal infuse resin. The final result would be a wood die that has “metal” pips, and a bit more weight than a hollow wood die. I’ve started some design already.

My worries are obviously with the balance on the die. Technically, even the hollow die is unbalanced as there is less mass on the “6” side than the “1” side, therefore over a sample of millions of rolls, the die would roll 6 more often than any other number. However, with the miniscule difference in a hollow wood die, this would rarely be a problem and would not be construed as a weighted die. However, filling the die with resin/metal increases the mass. The insert is heavier on the side with 6 pips as opposed to the 1 pip, so this does balance with the hollowness of the wood shell, however, I assume that the resin/metal pips would be more dense than the wood, so now the die will be unbalanced in the opposite direction.

I’ve been trying to find information on density of the materials, and once I do I can adjust the size of the pips to account for the added density. (i.e. the pip on the 1 side would be the biggest, then the size would decrease as the number of pips increased.) Of course, the balance could be thrown off by other things anyway - such as an air pocket in the interior cavity or something, so the exercise could just be a big waste of time.

die layout.pdf (4.6 KB)


#2

Here’s another thread discussing dice:


#3

You can calculate the volumes of the pips amd then adjust pip dia as needed to get volume on all sides the same


#4

If you don’t want to fill the complete interior, you could fill the pips with resin before you assemble the die. You’ll get the metal pips that way and save a lot of resin. But if you want to have the added weight, then you probably want fill the whole thing.


#5

You could make a die that has the 6 pips engraved on each side but only color the ones that need to be to get all the numbers correct. The small layer of paint wouldn’t be enough to cause enough difference in the weight…maybe…or


#6

And there’s the simpler answer. The density of the material is uniform, therefore the volume is enough to ensure balance. Thank you @Clone

@joe I like that idea as well. I do want the weight, but I could fill the interior with pure resin or some other material which would be cheaper than using the metal throughout. Of course each added material creates a source of imbalance. Also, the volume on this is very small (the interior cavity is only about a 1/2" cube) so the cost is not a lot… however, it is easy to see that with the volume of one interior cube I could easily make like 20 more dice.


#7

I have wondered about whether it would work to etch the complementary number of pips on the inside of each face so there are a total of 7 pips on each side, with only the correct number on the outside.


#8

Not a bad idea… And gives me interesting ideas for a game where you can flip the face of the die.


#9

Might be easier to calculate the thickness of the internal sides to change the center of gravity. So like the side with the 6 would be just a touch thicker while the 1 would be a bit thinner.

Or maybe that just seems easier to my brain. :slight_smile:


#10

Isn’t a normal die well within fitting in the bed of the Glowforge? So maybe just have the GF engrave the proper number of deep holes to hold your material from a solid cube then fill with your preferred material.

for balance issues make the 1 spot 6 times larger by volume than each pip on the 6 side. Similar rations 2 and 5 and 3 and 4 should end up pretty closed to balanced I would suspect.


#11

I like this idea. I’ll put it to the test soon. I have a chinese laser on the way.


#12

Sure… but then I have to buy blank dice. I would rather cut dice out of a relatively cheap material (depending on sourcing).

@zerbyte75, the only problem with that is that plywood only comes in certain thicknesses, unless I’m engraving an entire side off of the die… which also messes with how the tabs holding it together will fit. At this point I like the idea of making the pips bigger or smaller to make the overall volume on a given side equal.


#13

Most dice aren’t perfect cubes, being rounded on the corners to make the roll easier.

I haven’t looked at the cost of laserable blank dice, but most of the blanks on amazon listed a 16mm side, that would be just over .6 inches and the GF should be able to cut .5 inches with a flip, so I’m thinking you could cut out your own blanks with the flip feature. The hourglass of the kerf might even be a good thing.

If you don’t have a precise way to round the corners, that could throw off the balance more than the size of the spots.


#14

McMaster-Carr sells acrylic cubes in sizes that might work in the GF:


#15

The second McMaster-Carr reference today. I should have ordered all the hardware for my bandsaw from them. It would have saved a lot of time traveling around finding just the right part. I still don’t think on line shopping enough. Thanks.


#16

@marmak3261 - Keep in mind that MMC will special order items for you. Their customer support is top notch!


#17

That is crazy-expensive though at $1.14 per 1/2" cube.


#18

I suppose you could always buy 1/2-in thick stock and cut your own with a table saw to save money, but you’d probably want to radius the edges and the cubes from MMC are already nicely radiused. That might be worth the cost to some.


#19

Have you thought about making the pips scale with the number? So that the 6 pips would have the same collective volume as the single pip?


#20

I see Clone already suggested that. hah