29 Replies Latest reply on Apr 3, 2018 12:46 PM by Christopher Estelow

# How to Model a 9 sided Dice

Hello. I have been given a task and I can't figure out where to begin. First one is to Model a RHOMBICUBOCTAHEDRON which I have already done and also I have found some Models already out there. The second task is to do a 9 sided dice. I can't find a name of the Shape and all the angles have to be equal. That's all I was given for information. HAHA Please help.

• ###### Re: How to Model a 9 sided Dice

so it seems to jump from 8 to 10 sides... the reason being is that those are equivalent numbers, 9 sides would have a triangle with a constant remainder such as .333333333

• ###### Re: How to Model a 9 sided Dice

Did you try Google? Admittedly, my search term came up with ten-sided dice when called "0 to 9".

"Note that this design is not isohedral. "

has similar shape.

There's also "magic" foolery:

From a background in study of pure isohedral and rhombohedral geometric forms, I think you have been asked to fail creatively. That's not going to prevent me from making an attempt at it.

• ###### Re: How to Model a 9 sided Dice

your best bet would be to start with an equilateral triangle, draw 9 on a piece of paper, cut to shape, then figure out what need to change.

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Some interesting tidbits here ...

Dice - Wikipedia

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This would do the trick.

Chris

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thats 27 sides... i would think only 9 sides would be counted, otherwise you could just make a sphere with numbers and opposing flat surfaces and call that a 9 sided die.

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Honestly, I think this approach is awesome, and it is very similar to how I would have done it. The design guarantees that the dice is fair, and is thinking outside of the box rather than just googling the problem. I imagine the professor is looking for unique solutions considering he asked for nine sides.

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That's wicked Dustin

Gave me this idea - Not sure if it would work, maybe needs a slight stretch or hollowing

edit:   or twist

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I think that one better fits the problem description of having equal sides too. It would be fun to 3D print and test some of the designs.

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Nathan Fortier wrote:

Hello. I have been given a task and I can't figure out where to begin. First one is to Model a RHOMBICUBOCTAHEDRON which I have already done and also I have found some Models already out there. The second task is to do a 9 sided dice. I can't find a name of the Shape and all the angles have to be equal. That's all I was given for information. HAHA Please help.

Nathan,

After reading some of the references posted by John Pesaturo it is clear that your directions are not possible, at least not as written.  It is not possible to have a 9-sided die where the faces and angles are all equal.  Either someone told you instructions and is not aware of the discrepancy in them, or they are aware and they just told you the equivalent of "get me some blinker fluid".

I suspect it is the former.

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Wow, you splurged, the "ID-10T" is the really, really good stuff!

Do they sell muffler bearings where you bought that?

• ###### Re: How to Model a 9 sided Dice

You are right, Todd, that IS the best brand.  And I make sure to specify only Fully Synthetic, but in my haste I could only find an image of the Syn Blend.  Forgive me.

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whats even better is when you convince someone that different colors of dielectric grease is how you turn a white bulb to blue.

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OMG!.. ok,.. that is good!...  and it is actually sold!...

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This site here has some funny items....definitely worth checking out!!

Chris

• ###### Re: How to Model a 9 sided Dice

Christopher Estelow wrote:

This site here has some funny items....definitely worth checking out!!

Chris

I was looking for a place with muffler bearings - THEY HAVE THEM!

good price too . . .

that is a whole lot of awesome, thanks for sharing!

• ###### Re: How to Model a 9 sided Dice

Glad I could share a good place to buys such items as muffler bearings, elbow grease, cross-drilled brake lines or the seasonal tire air!!!

Chris

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Glad you mentioned it, i'm still rolling on winter air - no wonder my mileage is so bad!

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Better change it to spring in a hurry or you'll be throwing money out the window.  Money you could use to get those muffler bearings you mentioned!!!

Chris

• ###### Re: How to Model a 9 sided Dice

It is interesting that the only 9 sided die that I can find looks like this:

It is basically just a sphere with 9 flats cut into it in a regular pattern.  Then a number stamped on the sphere opposite each flat.

Are you sure that they didn't mean a 10 sided die? (the reason why I ask is that a 10 sided die is stamped with the number 0-9)

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That greatly resembles the geometry which would result from the study model I started, only hollow. I took a sphere and sliced circles into it with planes. I gave up and got back to work.

I like that one better.

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that's what i said! i think this is one of those professors just trying to fool some students...possibly searching for the answer of why its not possible rather than the actual model

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I don't remember ever seeing a 9-sided dice in my Dungeons and Dragons & other role playing games.

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I found it. You throw it using a caber-toss technique.

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Nathan,

Please understand that in our offers of help we are having a little fun, but we are not making fun of you.  Today has just been a goofy day for me - a little punchy and unproductive.

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I'm not making fun. I love geometry and started sculpting in sheet metal to create an exploded cuboctohedron with pyramids extended from the octo faces. I seriously wondered if there was something I missed.

Nathan, you said, "and all the angles have to be equal."  Does that mean the angles of the edges on the faces, that all faces need to be same, or that the angles BETWEEN faces need to be the same? Dan's image shows equal angles between "faces". 4-sided and odd-sided dice must all have a vertex at topmost point, so that you're reading from the face which it lands on, not the face which lands up. Dan's image has a number (up) in the framework that is opposite of a face (down), similar to a 3- or 4-sided die.

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Hello,

It's a Enneahedron - Wikipedia

The truncated triangular looks cool, but the yellow sides are square (this is the only that spins)

Cheers,

Kevin

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Was it the April Fools' Day prank?

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LOL.   That would be epic!