I was toying with the idea of trying to make a Mayan calendar (short count 52 year cycle). Basically there would be three gears. One with thirteen symbols / teeth; one with twenty symbols / teeth, and a third with 365 symbols / teeth. The 13 gear is meshed inside the 20 gear which is meshed against the 365 gear. I am seeing a few slight hitches though: 1) how to keep the gears meshed after assembly 2) how to assemble the 365 gear (it seems very unlikely I could print it in one shot, I'd need some way of making parts that allows them to be joined after printing, not sure if others have input on how close things have to be to snap fit together) 3) how to make the designs for each place (I need to make a stamp type thing with a freeform drawing) <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> Virus-free. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

1) can you post a sketch of roughly what the arrangement is to help give advice on this front. 2) ? 3) drawings can be easily traced in Inkscape to convert them to vector form. When in vector form you can select all and use the add points option until there are enough points in all the curves to represent the curves with straight lines. Then you can convert all curves lines to straight lines and save as dxf which should import() into OpenSCAD. Sent from my iPhone > On 3 Jan 2018, at 12:54 pm, Dan Shriver <tabbydan@gmail.com> wrote: > > I was toying with the idea of trying to make a Mayan calendar (short count 52 year cycle). > > Basically there would be three gears. One with thirteen symbols / teeth; one with twenty symbols / teeth, and a third with 365 symbols / teeth. > > The 13 gear is meshed inside the 20 gear which is meshed against the 365 gear. > > I am seeing a few slight hitches though: > > 1) how to keep the gears meshed after assembly > 2) how to assemble the 365 gear (it seems very unlikely I could print it in one shot, I'd need some way of making parts that allows them to be joined after printing, not sure if others have input on how close things have to be to snap fit together) > 3) how to make the designs for each place (I need to make a stamp type thing with a freeform drawing) > > Virus-free. www.avast.com > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org

On 2) the problem is a 365 glyph gear will be way too big if the glyphs are decently sized. I'll post an animated link on how it is supposed to work later. On Jan 3, 2018 12:26 AM, "Greg Frost" <gregorybartonfrost@gmail.com> wrote: > 1) can you post a sketch of roughly what the arrangement is to help give > advice on this front. > > 2) ? > > 3) drawings can be easily traced in Inkscape to convert them to vector > form. When in vector form you can select all and use the add points option > until there are enough points in all the curves to represent the curves > with straight lines. Then you can convert all curves lines to straight > lines and save as dxf which should import() into OpenSCAD. > > > Sent from my iPhone > > On 3 Jan 2018, at 12:54 pm, Dan Shriver <tabbydan@gmail.com> wrote: > > I was toying with the idea of trying to make a Mayan calendar (short count > 52 year cycle). > > Basically there would be three gears. One with thirteen symbols / teeth; > one with twenty symbols / teeth, and a third with 365 symbols / teeth. > > The 13 gear is meshed inside the 20 gear which is meshed against the 365 > gear. > > I am seeing a few slight hitches though: > > 1) how to keep the gears meshed after assembly > 2) how to assemble the 365 gear (it seems very unlikely I could print it > in one shot, I'd need some way of making parts that allows them to be > joined after printing, not sure if others have input on how close things > have to be to snap fit together) > 3) how to make the designs for each place (I need to make a stamp type > thing with a freeform drawing) > > > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> Virus-free. > www.avast.com > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link> > <#m_-789861385923706324_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org > > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org > >

I am not certain that this is the calendar you are referring to, but attached is a picture of an Aztec calendar produced in OpenSCAD from an AutoCAD DXF file. I can send you the DXF file if it would help. <http://forum.openscad.org/file/t1309/aztec.jpg> -- Sent from: http://forum.openscad.org/

No it isn't. That's a replica of the Aztec sun stone. All the Mesoamerican cultures, had "short count" 52 year "centuries", which were generated by the meshing of a 260 day cycle with a 365 day cycle. Each used their own glyphs (except the ceremonial month day were alike). I think the 260 day cycle was always 20 "months" of 13 days each, and the 365 cycle was not subdivided. On Jan 3, 2018 8:28 AM, "cbernhardt" <charlie@carols62.com> wrote: > I am not certain that this is the calendar you are referring to, but > attached > is a picture of an Aztec calendar produced in OpenSCAD from an AutoCAD DXF > file. I can send you the DXF file if it would help. > <http://forum.openscad.org/file/t1309/aztec.jpg> > > > > -- > Sent from: http://forum.openscad.org/ > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >

Please post a picture of the calendar that you are working with. Internet search returns numerous designs. Charles -- Sent from: http://forum.openscad.org/

If you arrange it like this <http://forum.openscad.org/file/t887/maya.png> you'll have two rings and a sun and can use coaxial planetary gearing (PG) with fixed planetary carriers (giving good stability and providing all bearing points,necessary). From gold(13) to blue(20) you need i=20, which you get by a two stage PG system with i1 = 5, i2 = 4. It will be hidden behind the sun. From blue to red, you need i = 365/260, which you get by coaxially adding an outer single stage PG system that connects a sun gear with 260 theeth to the blue ring and a ring gear with 365 teeth to the red ring. If you use properly designed herringbone gears they'll stay well meshed after assembly, without further means. For assembly the elastic properties of the rings will be you friend. Don't worry about clearance, if you don't have to save energy. With this ratios and speeds clearance can be 0. It is not difficult to use a lego-or puzzle-like connection system to compose the rings/ring gears from different parts. They can be adjusted for final glue when operating the system itself, of course starting from inside. -- Sent from: http://forum.openscad.org/

Looking at it again I guess it would be at least four gears because the "secular" 365 calendar is subdivided in an odd way. 18 months of 20 days each, plus one special month at the end of just five days. The Aztec sun stone is odd because it mixes various info together. It has calendric info but is not a calendar, it has some royal history, and in the center a prediction about how the 5th" sun/ world" would end. The Aztecs believed they were living in the 5th world or sun, of a sequence of such worlds/ suns. I am curious how that was generated since it could help me with the glyphs. On Jan 3, 2018 8:28 AM, "cbernhardt" <charlie@carols62.com> wrote: > I am not certain that this is the calendar you are referring to, but > attached > is a picture of an Aztec calendar produced in OpenSCAD from an AutoCAD DXF > file. I can send you the DXF file if it would help. > <http://forum.openscad.org/file/t1309/aztec.jpg> > > > > -- > Sent from: http://forum.openscad.org/ > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >

I think this shows and describes the calendar cycles and how they go together. https://youtu.be/BeE-3BBqG58 > On Jan 3, 2018, at 12:25 PM, Dan Shriver <tabbydan@gmail.com> wrote: > > Looking at it again I guess it would be at least four gears because the "secular" 365 calendar is subdivided in an odd way. 18 months of 20 days each, plus one special month at the end of just five days. > > The Aztec sun stone is odd because it mixes various info together. It has calendric info but is not a calendar, it has some royal history, and in the center a prediction about how the 5th" sun/ world" would end. The Aztecs believed they were living in the 5th world or sun, of a sequence of such worlds/ suns. > > I am curious how that was generated since it could help me with the glyphs. > >> On Jan 3, 2018 8:28 AM, "cbernhardt" <charlie@carols62.com> wrote: >> I am not certain that this is the calendar you are referring to, but attached >> is a picture of an Aztec calendar produced in OpenSCAD from an AutoCAD DXF >> file. I can send you the DXF file if it would help. >> <http://forum.openscad.org/file/t1309/aztec.jpg> >> >> >> >> -- >> Sent from: http://forum.openscad.org/ >> >> _______________________________________________ >> OpenSCAD mailing list >> Discuss@lists.openscad.org >> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org

That's a decent representation. But they simplified the "secular year" (365 day part) to be one BIG ring/gear (to get around the problem of the odd month at the end). I'm wondering if there is some way to do it as four gears. If it was just a 260 day cycle (20 months of 13 days each) and a 360 day cycle (18 months of 20 days each) it would be relatively easy. Something would simultaneously turn the 13 day ("sacred month") wheel 1/13 revolution and the 20 day ("secular month") wheel 1/20th revolution. Each month day wheel would have one tooth between the first and last days of the month that tooth would cause the outer ring to rotate one spot (advancing the "month"). The two outer rings would not need teeth between them (this would reduce wear caused by things not being perfect in the real world and thus having the months maybe not being perfectly in synch). The big problem is that the "secular year" has 365 days and thus 19 months with the last one being only 5 days. If I call the last month Dec and the first one Jan... I have an imperfect workaround. The 20 day month ring has 2 teeth. One between 1 & 20 (big tooth) and one between 5 & 6 (small tooth). The month name ring has a smaller inner radius for the last month so it catches at 5... The problem is that instead of starting over on Jan 1, the first day of the new year will read Jan 6, not sure how to correct that. <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> Virus-free. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> On Wed, Jan 3, 2018 at 3:10 PM, Mark Peeters <peetersmarkg@gmail.com> wrote: > I think this shows and describes the calendar cycles and how they go > together. > https://youtu.be/BeE-3BBqG58 > > On Jan 3, 2018, at 12:25 PM, Dan Shriver <tabbydan@gmail.com> wrote: > > Looking at it again I guess it would be at least four gears because the > "secular" 365 calendar is subdivided in an odd way. 18 months of 20 days > each, plus one special month at the end of just five days. > > The Aztec sun stone is odd because it mixes various info together. It has > calendric info but is not a calendar, it has some royal history, and in the > center a prediction about how the 5th" sun/ world" would end. The Aztecs > believed they were living in the 5th world or sun, of a sequence of such > worlds/ suns. > > I am curious how that was generated since it could help me with the > glyphs. > On Jan 3, 2018 8:28 AM, "cbernhardt" <charlie@carols62.com> wrote: > >> I am not certain that this is the calendar you are referring to, but >> attached >> is a picture of an Aztec calendar produced in OpenSCAD from an AutoCAD DXF >> file. I can send you the DXF file if it would help. >> <http://forum.openscad.org/file/t1309/aztec.jpg> >> >> >> >> -- >> Sent from: http://forum.openscad.org/ >> >> _______________________________________________ >> OpenSCAD mailing list >> Discuss@lists.openscad.org >> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >> > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org > > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org > >