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A new pyramid-like shape always lands the same side up

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Re: A new pyramid-like shape always lands the same side up

#51

Post by gerdesj »

ortusdux wrote: post #39
ChuckMcM wrote: post #16

Worst D-4 ever! But more seriously, I wonder how closely you could get to an non-uniform mass polyhedra which had 'knife edge' type balance. Which is to say; 1) Construct a polyhedra with uneven weight distribution which is stable on exactly two faces. 2) Make one of those faces much more stable than the other, so if it is on the limited stability face and disturbed, it will switch to the high stability face. A struc…

You jest, but I knew a DND player with a dice addicting that loved showing off his D-1 Mobius strip dice - https://www.awesomedice.com/products/awd101?variant=45578687... For some reason he did not like my suggestion that he get a #1 billard ball.

Love it - any sphere will do.

A ping pong ball would be great - the DM/GM could throw it at a player for effect without braining them!

(billiard)

Re: A new pyramid-like shape always lands the same side up

#52

Post by hammock »

gerdesj wrote: post #51
ortusdux wrote: post #39

Earlier quoted context omitted.

You jest, but I knew a DND player with a dice addicting that loved showing off his D-1 Mobius strip dice - https://www.awesomedice.com/products/awd101?variant=45578687... For some reason he did not like my suggestion that he get a #1 billard ball.

Love it - any sphere will do. A ping pong ball would be great - the DM/GM could throw it at a player for effect without braining them! (billiard)

Or any mobius strip

Re: A new pyramid-like shape always lands the same side up

#53

Post by [deleted] »

ChuckMcM wrote: post #16

Worst D-4 ever! But more seriously, I wonder how closely you could get to an non-uniform mass polyhedra which had 'knife edge' type balance. Which is to say; 1) Construct a polyhedra with uneven weight distribution which is stable on exactly two faces. 2) Make one of those faces much more stable than the other, so if it is on the limited stability face and disturbed, it will switch to the high stability face. A struc…

[deleted]

Re: A new pyramid-like shape always lands the same side up

#54

Post by [deleted] »

ChuckMcM wrote: post #16

Worst D-4 ever! But more seriously, I wonder how closely you could get to an non-uniform mass polyhedra which had 'knife edge' type balance. Which is to say; 1) Construct a polyhedra with uneven weight distribution which is stable on exactly two faces. 2) Make one of those faces much more stable than the other, so if it is on the limited stability face and disturbed, it will switch to the high stability face. A struc…

[deleted]

Re: A new pyramid-like shape always lands the same side up

#55

Post by gus_massa »

ChuckMcM wrote: post #16

Worst D-4 ever! But more seriously, I wonder how closely you could get to an non-uniform mass polyhedra which had 'knife edge' type balance. Which is to say; 1) Construct a polyhedra with uneven weight distribution which is stable on exactly two faces. 2) Make one of those faces much more stable than the other, so if it is on the limited stability face and disturbed, it will switch to the high stability face. A struc…

A solid tall cone is quite similar to what you want. I guess it can be tweaked to get a polyhedra.

Re: A new pyramid-like shape always lands the same side up

#56

Post by kazinator »

Nevermark wrote: post #38
kazinator wrote: post #21

This is categorically different from the Gömböc, because it doesn't have uniform density. Most of its mass is concentrated in the base plate.

> This tetrahedron, which is mostly hollow and has a carefully calibrated center of mass Uniform density isn't an issue for rigid bodies. If you make sure the center of mass is in the same place, it will behave the same way.

If the constraints are that an object has to be of uniform density, convex, and not containing any voids, then you cannot choose where its centre of mass will be, other than by changing it shape.

Re: A new pyramid-like shape always lands the same side up

#57

Post by nick238 »

tpurves wrote: post #7
mosura wrote: post #3

Somewhat disappointing that it won’t work with uniform density. More surprising it needed such massive variation in density and couldn’t just be 3d printed from one material with holes in.

That implies the interesting question though, which shape and mass distribution comes closest to, or would maximize relative uniformity?

Given they needed to use a tenuous carbon fiber skeleton and tungsten carbide plate, and a stray glob of glue throws off the balance...seems tough.

Re: A new pyramid-like shape always lands the same side up

#58

Post by gerdesj »

hammock wrote: post #52
gerdesj wrote: post #51

Earlier quoted context omitted.

Love it - any sphere will do. A ping pong ball would be great - the DM/GM could throw it at a player for effect without braining them! (billiard)

Or any mobius strip

I think a spherical D1 is far more interesting than a Möbius strip in this case.

Dn: after the Platonic solids, Dn generally has triangular facets and as n increases, the shape of the die tends towards a sphere made up of smaller and smaller triangular faces. A D20 is an icosahedron. I'm sure I remember a D30 and a D100.

However, in the limit, as the faces tend to zero in area, you end up with a D1. Now do you get a D infinity just before a D1, when the limit is nearly but not quite reached or just a multi faceted thing with a lot of countable faces?

Re: A new pyramid-like shape always lands the same side up

#59

Post by jayd16 »

ChuckMcM wrote: post #16

Worst D-4 ever! But more seriously, I wonder how closely you could get to an non-uniform mass polyhedra which had 'knife edge' type balance. Which is to say; 1) Construct a polyhedra with uneven weight distribution which is stable on exactly two faces. 2) Make one of those faces much more stable than the other, so if it is on the limited stability face and disturbed, it will switch to the high stability face. A struc…

I imagine a dowel that is easily tipped over fits your description but I must be missing something.

Re: A new pyramid-like shape always lands the same side up

#60

Post by MPSimmons »

ortusdux wrote: post #39
ChuckMcM wrote: post #16

Worst D-4 ever! But more seriously, I wonder how closely you could get to an non-uniform mass polyhedra which had 'knife edge' type balance. Which is to say; 1) Construct a polyhedra with uneven weight distribution which is stable on exactly two faces. 2) Make one of those faces much more stable than the other, so if it is on the limited stability face and disturbed, it will switch to the high stability face. A struc…

You jest, but I knew a DND player with a dice addicting that loved showing off his D-1 Mobius strip dice - https://www.awesomedice.com/products/awd101?variant=45578687... For some reason he did not like my suggestion that he get a #1 billard ball.

I've always seen a D1 as a bingo ball...
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