# Where can I find dimensions for making a replica Roman dodecahedron? **URL:** \ **Category:** Factual Questions\ **Created:** [October 31, 2011, 10:32pm UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434 "2011-10-31T22:32:32Z")\ **Posts on this page:** 20\ **Page:** 5
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [December 4, 2012, 12:01am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/81 "2012-12-04T00:01:32Z")
> [@WonderWheeler](#): > > There’s a recent theory published by an Italian lady that different sizing of holes allows a roman soldier to sight through it, viewing markings on a roman standard, to estimate distance. Paper published this spring. That was my first guess, but doesn’t explain the balls. If it’s a utilitarian object, rough corners probably wouldn’t have mattered. If it’s cast, there wouldn’t be rough corners. I think the corner balls must be functional. > [@China\_Guy](#): > > What is a pasta serving size measure? Spaghetti serving size measure – doesn’t work for other pasta types. It’s a small paddle with a hole in each end, about 1" in diameter, for one serving, and one with twice the area for two servings (or whatever). You pick the right hole, and “pour” the pasta from the box through the hole into the pasta pot. Use the paddle to hold the unused pasta back into the box. Or something like that. I’ve seen the tool but never actually used one. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 4, 2012, 12:10am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/82 "2012-12-04T00:10:45Z")
I’ve suggested this before, but it could be a universal eggcup. Big hole upwards if it’s a swan or goose egg, little hole if it’s quail. Except that I don’t know if the Romans even used egg cups. Still, it could be a universal stand for some kind of small conical bottles like [this](http://www.google.co.uk/imgres?um=1&hl=en&client=firefox-a&tbo=d&rls=org.mozilla:en-GB:official&biw=1024&bih=470&tbm=isch&tbnid=rR_tFDxJMVpMGM:&imgrefurl=http://images.goldbergauctions.com/php/chap_auc.php%3Fsite%3D1%26lang%3D1%26sale%3D14%26chapter%3D45%26page%3D1&docid=GLtD4IBudomsvM&imgurl=http://64.60.141.195/photos/14thumbs/50337.jpg&w=200&h=511&ei=-D69ULXIFeqx0AXD_YGIBQ&zoom=1&iact=hc&vpx=476&vpy=-2&dur=70&hovh=359&hovw=140&tx=80&ty=70&sig=104086671089193071729&page=2&tbnh=150&tbnw=65&start=17&ndsp=23&ved=1t:429,r:36,s:0,i:192) one - maybe so that it could be left unstoppered, hands-free, either to be ready to use (for something like medicine) or to allow perfume to evaporate and fragrance a room. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [December 4, 2012, 12:18am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/83 "2012-12-04T00:18:15Z")
The problem with it being a measuring tool for pipe, pasta, etc. is that a flat, bronze plate with holes punched in it could serve the same function. And it would be an order of magnitude easier to manufacturer vs. a dodecahedron. Why would they go to all the trouble to make a dodecahedron? ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 4, 2012, 12:49am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/84 "2012-12-04T00:49:01Z")
It can’t be a measuring tool for anything (as with pasta) that needs to pass right through the device, as opposing holes are of different sizes - so you’d always just get the smaller portion of pasta. I’m liking my Apothecary’s bottle stand notion at the moment. There are quite a lot of examples of Roman and Byzantine perfume and unguent vials that are conical and would not stand up on their own - if you had need to keep the bottle unstoppered (for example, treating a wound, or just applying massage oil or perfume), you’d need a stand for it. Or a bottle with a flat bottom, which also exists, but for some reason, was not universal. ---
**Author:** ![WonderWheeler](https://avatars.discourse-cdn.com/v4/letter/w/ed655f/32.png) [@WonderWheeler](https://boards.straightdope.com/u/WonderWheeler)\ **Post date:** [December 4, 2012, 2:53am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/85 "2012-12-04T02:53:01Z")
Interesting idea! In the ancient world amphoras, ampule-like bottles and even some statues like the Venus of Willendorf (sp?) did not have bases. They were often set in soft earth (or ships ballast) where the lack of a base was an advantage. They had blunt conical bases. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [December 4, 2012, 3:48am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/86 "2012-12-04T03:48:35Z")
The bottle-stand hypothesis also has the advantage that it would explain a certain amount of ornamentation. Sure, you could use a rectangular box for the same purpose, but it wouldn’t be as pretty. ---
**Author:** ![foolsguinea](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/foolsguinea/32/14751_2.png) [@foolsguinea](https://boards.straightdope.com/u/foolsguinea)\ **Post date:** [December 4, 2012, 4:34am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/87 "2012-12-04T04:34:14Z")
> [@Mangetout](#): > > I’ve suggested this before, but it could be a universal eggcup. Big hole upwards if it’s a swan or goose egg, little hole if it’s quail. > > Except that I don’t know if the Romans even used egg cups. Still, it could be a universal stand for some kind of small conical bottles like [this](http://www.google.co.uk/imgres?um=1&hl=en&client=firefox-a&tbo=d&rls=org.mozilla:en-GB:official&biw=1024&bih=470&tbm=isch&tbnid=rR_tFDxJMVpMGM:&imgrefurl=http://images.goldbergauctions.com/php/chap_auc.php%3Fsite%3D1%26lang%3D1%26sale%3D14%26chapter%3D45%26page%3D1&docid=GLtD4IBudomsvM&imgurl=http://64.60.141.195/photos/14thumbs/50337.jpg&w=200&h=511&ei=-D69ULXIFeqx0AXD_YGIBQ&zoom=1&iact=hc&vpx=476&vpy=-2&dur=70&hovh=359&hovw=140&tx=80&ty=70&sig=104086671089193071729&page=2&tbnh=150&tbnw=65&start=17&ndsp=23&ved=1t:429,r:36,s:0,i:192) one - maybe so that it could be left unstoppered, hands-free, either to be ready to use (for something like medicine) or to allow perfume to evaporate and fragrance a room. I like this universal stand idea. It doesn’t explain their apparent rarity, though. ---
**Author:** ![WonderWheeler](https://avatars.discourse-cdn.com/v4/letter/w/ed655f/32.png) [@WonderWheeler](https://boards.straightdope.com/u/WonderWheeler)\ **Post date:** [December 4, 2012, 5:10am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/88 "2012-12-04T05:10:21Z")
> [@foolsguinea](#): > > I like this universal stand idea. It doesn’t explain their apparent rarity, though. And who wants to be buried with a bottle rack. Especially an empty one. ---
**Author:** ![WonderWheeler](https://avatars.discourse-cdn.com/v4/letter/w/ed655f/32.png) [@WonderWheeler](https://boards.straightdope.com/u/WonderWheeler)\ **Post date:** [December 4, 2012, 7:27am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/89 "2012-12-04T07:27:08Z")
I wonder if it was a glorified Sterno heater. The different size holes could handle different sized bottles to warm perfume perhaps. Maybe we need to build one of these suckers to experiment. Have been collecting brass and aluminum and have a little foundry setup. Maybe I can claim its a gift for the wife… ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 4, 2012, 7:31am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/90 "2012-12-04T07:31:13Z")
If it’s not an actual heater, another use could be to hold a bottle upright when placed in a pot of hot water to melt the contents… I am going to make one. ---
**Author:** ![WonderWheeler](https://avatars.discourse-cdn.com/v4/letter/w/ed655f/32.png) [@WonderWheeler](https://boards.straightdope.com/u/WonderWheeler)\ **Post date:** [December 4, 2012, 8:32am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/91 "2012-12-04T08:32:37Z")
Here’s my target. > **[File:Dodecaëder potiers.JPG](https://commons.wikimedia.org/wiki/File:Dodeca%C3%ABder_potiers.JPG)** Ugliest one I could find. Might be doable. Will probably build the core first. Then coat that with wax and work that. Will probably be a zinc (potmetal) casting, although I haven’t tried that yet, it doesn’t have to be as hot as aluminum, and brass is probably over my head. Might even try to heat it in a stainless steel pot on an outdoor range. Will probably try to match the dimensions we found and showed here. Care to race? 😉 ---
**Author:** ![WonderWheeler](https://avatars.discourse-cdn.com/v4/letter/w/ed655f/32.png) [@WonderWheeler](https://boards.straightdope.com/u/WonderWheeler)\ **Post date:** [December 4, 2012, 9:19am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/92 "2012-12-04T09:19:45Z")
We talked a little about cores in casting, here is a little video describing the making of a core by a great retired shop teacher going by the name tubalcain [FOUNDRY PATTERN MAKING part 6 Steam Engine cores tubalcain - YouTube](http://www.youtube.com/watch?v=OedpFHYIkDA) (model steam engine video 6) FYI, another that talks about the basics of pattern making, cores, shrinkage [FOUNDRY PATTERN MAKING part 1 Steam Engine tubalcain - YouTube](http://www.youtube.com/watch?v=h-c4_Ukqgx4) (model steam engine video 1) I wonder if I should start another thread or continue description of construction of a dodecahedron on another website. Any suggestions, interest? ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [December 4, 2012, 12:55pm UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/93 "2012-12-04T12:55:39Z")
> [@WonderWheeler](#): > > I wonder if I should start another thread or continue description of construction of a dodecahedron on another website. > > Any suggestions, interest? If you start a new thread with “casting” or whatever technique in the title, you’ll probably get people who are interested in that, but aren’t reading this thread. And if you do it on this board, I’ll get to watch. 🙂 ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 4, 2012, 1:47pm UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/94 "2012-12-04T13:47:34Z")
> [@WonderWheeler](#): > > Care to race? 😉 I was thinking that myself, but actually, I think I’d prefer to collaborate. Do you have your own blog or website? I’ll be featuring my build on [Atomic Shrimp](http://www.atomicshrimp.com) ---
**Author:** ![WonderWheeler](https://avatars.discourse-cdn.com/v4/letter/w/ed655f/32.png) [@WonderWheeler](https://boards.straightdope.com/u/WonderWheeler)\ **Post date:** [December 5, 2012, 1:08am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/95 "2012-12-05T01:08:07Z")
Had one for a couple years, but hardly used it and deleted it a few weeks ago. Nice site Atomic. See you’re an experienced french knitting instructor [![](https://img.youtube.com/vi/0LVzSuPFhNk/hqdefault.jpg "French Knitting instructions using a home made wooden device") ](https://www.youtube.com/watch?v=0LVzSuPFhNk) I suppose you don’t see any advantage in having a french knitting bobbin with 5 pegs and choice of different sized holes… Also can’t help thinking how quick and clean it would be to make a Roman Dodecahedron out of tin, embossed, although maybe with the big holes with those edges bent over or hemmed in some way ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 5, 2012, 7:16am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/96 "2012-12-05T07:16:15Z")
I have wondered about whether they could be knitting bobbins, however, the hole size is only one variable in the equation - you’d really want a device with different holes and different peg counts. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 5, 2012, 8:15am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/97 "2012-12-05T08:15:52Z")
> [@WonderWheeler](#): > > Also can’t help thinking how quick and clean it would be to make a Roman Dodecahedron out of tin, embossed, although maybe with the big holes with those edges bent over or hemmed in some way It would, for a prototype, but the finished article would lack the necessary heft and integrity that a cast or soldered-plate example would possess - and the trouble is at this point, we don’t really know what properties of these items are critical, and which are incidental. My plan is to cut the pentagons from wax sheets, join them together, then add wax pegs into each vertex - it should be possible to create a wax form without a core, as long as I work in a cold place, with a heated container of wax for jointing. I’ve done some reasonably successful lost wax casting before - melting down pewter tankards for material. The one thing I need to work out is the height of the individual pentagons - the measurements we’ve seen so far in this thread provide the height of the assembled dodecahedron - there must be a relatively simple way to work back the size of the pentagons from that. Glad you liked my site, BTW. ---
**Author:** ![WonderWheeler](https://avatars.discourse-cdn.com/v4/letter/w/ed655f/32.png) [@WonderWheeler](https://boards.straightdope.com/u/WonderWheeler)\ **Post date:** [December 5, 2012, 9:56am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/98 "2012-12-05T09:56:06Z")
> [@Mangetout](#): > > … > The one thing I need to work out is the height of the individual pentagons - the measurements we’ve seen so far in this thread provide the height of the assembled dodecahedron - there must be a relatively simple way to work back the size of the pentagons from that. Shouldn’t be too difficult with our CAD program. Might not be able to get to it for a couple days here. There are also some mathamatical type web links that have many of the required equations also. I have a drawing already started as a template based on the Zagreb one (from a poster), was going to rescale it to match the dimensions at some point anyway. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 5, 2012, 10:20am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/99 "2012-12-05T10:20:53Z")
Ultimately, it’s just going to be a ratio (the relationship between the height of the pentagons and the distance between the two faces of the resulting dodecahedron - which should then work for any size model. Also. any glassblowers reading this? Or does anyone know one? ---
**Author:** ![WonderWheeler](https://avatars.discourse-cdn.com/v4/letter/w/ed655f/32.png) [@WonderWheeler](https://boards.straightdope.com/u/WonderWheeler)\ **Post date:** [December 5, 2012, 11:22am UTC](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434/100 "2012-12-05T11:22:50Z")
Did some work on a top and side view in CAD Square Height To Side Factor: 0.4490 For a 66 mm high unit, side segment equals 29.64 mm I’ll want to double-check later, but 30 mm on a side, for now. That’s for a “square” unit, sitting flat on one pentagon, the height without knobs 66 mm from bottom horizontal pentagon to top horizontal pentagon. [Previous page](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434.md?page=4) [Next page](https://boards.straightdope.com/t/where-can-i-find-dimensions-for-making-a-replica-roman-dodecahedron/601434.md?page=6)