Mayan calendar

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Re: Mayan calendar

cbernhardt
This post was updated on .
cacb wrote
> Hi Charles
>
> Sounds like you have some issue with your computer, it should work fine.
> I don't know if OpenSCAD is compiled using MSVC++ on Windows, but your
> message seems to indicate so.
> Here are the corresponding numbers for my 3 computers, all run ok.
> Carsten Arnholm

I re-installed the 64 bit version of OpenSCAD 2015.03-2 and it seems to be
working fine.

OS Win 7 64
OpenSCAD version 2015.03-2
Intel Core i7-6700
3.40GHz
16GB RAM

with linear_extrude
render F5 32 seconds
render F6 31 seconds

linear_extrude removed:
render F5 4 seconds
render F6 31 seconds

Thanks for all the help,
Charles



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Re: Mayan calendar

DanS
So I'm not trying to beat a dead horse here.... but I'm trying to figure out how to make the "solar" 365 day calendar more like the "ceremonial" 260 day one.

The 260 day calendar has months (20) with exactly the same number of days (13) so it is easy to implement as two gears.  One has 13 spots and one tooth.  The other has 20 notches (one for each month)

The 365 day calendar has 18 months of 20 days and one month of 5 days.

I have a simplified drawing for how I'd like to tackle this.  For simplification I've only put notches in the outer months ring in four spots.
The ceremonial calendar is on the left and the solar one on the right.
For the solar one it would have 18 notches between the months (that the tall tooth between 20 and 1 would catch), and a small tooth on the month ring between the first and last months of the year (calling them "Dec" and "Jan" here since that is easier to write than a glyph) that would catch on a small tooth on the month ring between 5 & 6.
The result would "sort of work" except the first day of the new solar year would be Jan 6.

Are there any clever tricks I could use to reset the day of the month wheel after "Dec 5" so it reads "Jan 1" the next day?

Inline image 1

On Sat, Jan 6, 2018 at 10:33 AM, cbernhardt <[hidden email]> wrote:
cacb wrote
> Hi Charles
>
> Sounds like you have some issue with your computer, it should work fine.
> I don't know if OpenSCAD is compiled using MSVC++ on Windows, but your
> message seems to indicate so.
> Here are the corresponding numbers for my 3 computers, all run ok.
> Carsten Arnholm

I re-installed the 64 bit version of OpenSCAD 2015.03-2 and it seems to be
working fine.

OS Win 7 64
OpenSCAD version 2015.03-2
Intel Core i7-6700
3.40GHz
16GB RAM

with linear_extrude
render F5 4 seconds
render F6 4 seconds

linear_extrude removed:
render F5 4 seconds
render F6 4 seconds

Thanks for all the help,
Charles



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Re: Mayan calendar

Ronaldo
A Geneva drive with irregular 19 pin arrangement?


2018-01-11 20:57 GMT-02:00 Dan Shriver <[hidden email]>:

Are there any clever tricks I could use to reset the day of the month wheel after "Dec 5" so it reads "Jan 1" the next day?

Inline image 1


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Re: Mayan calendar

fred_dot_u
I find it curious that I read this post only moments prior to watching this
video:

Solvespace Create Geneva Drive <https://www.youtube.com/watch?v=nso4tDuYdm8>  

Even if one does not care to learn about Solvespace, the video creator
provides formulae for calculating the components of a Geneva drive. As I
watched the video, I realized that one could easily transport the
information into an OpenSCAD file. Okay, maybe not easily, but if I think I
could do it, it can't be too difficult!

The video comment section includes downloads for spreadsheet in OpenOffice
as well as some Solvespace files. Because OpenSCAD supports mathematical
operations, I believe it would be a single document, as opposed to the two
files referenced in the video.



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Re: Mayan calendar

DanS
In reply to this post by Ronaldo
I looked up the Geneva drive and see that it would solve an unstated problem of mine.  If I used a Geneva drive with one pin and the cross on the underside of the "day of the month" wheel, it would change a continuously turning motion into discrete movement of the day wheel.

I believe you have an idea for how to reset the day but I do not understand it.  Can you provide a diagram of how it works?

Maybe if I have a second cross at the top of the solar month day and there is pin (not sure if it would need to be on a spring or not) on the "month of the year" wheel that causes the "day of the month" wheel to spin back from 5 to 1.  The only problem with that is I would have to somehow disengage the Geneva drive on the bottom...  I'm sure that's not what you are suggesting (since you mentioned "19 pin irregular").  I'm just having trouble imaging what you are saying.

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On Thu, Jan 11, 2018 at 6:38 PM, Ronaldo Persiano <[hidden email]> wrote:
A Geneva drive with irregular 19 pin arrangement?


2018-01-11 20:57 GMT-02:00 Dan Shriver <[hidden email]>:

Are there any clever tricks I could use to reset the day of the month wheel after "Dec 5" so it reads "Jan 1" the next day?

Inline image 1


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Re: Mayan calendar

Ronaldo
My knowledge of mechanisms is very basic. But, yes, the purpose of Geneva drive is to produce an intermittent motion from a continuous rotating motion drive. It is an indexing system that may have its place in your project.

I tried to design my idea but failed: I don't think Geneva drive would do the trick. In fact, I think now a better solution for your quest would be to consider a variable sectional gear mechanism like the one is found in Gearwheels from Hell. Those mechanisms allow to have two or more gear transmission ratio during the rotation. But don't ask how, at least not now. :)

However, I guess the best solution to assign month names to the 365 day Mayan calendar is found in the Youtube video Mark Peeters referenced here days ago. In the video, there are three geared wheels: one with 13 numbers, one with 20 day glyph names and, the year wheel, with 365 days. The year wheel have 365 combinations of a month day number and a month glyph. There are 19 month glyphs, one of them appearing just 5 times on the wheel and the others appearing 20 times. So the months are not in a separate wheel but in the 365 day year wheel. If you stop the video at 1:38 you will see the 5 day month in detail. 

Each specific combination of one number (first weel), a day glyph (second weel) and a pair [day number, month glyph] are aligned just once in 18980 days. This is the Calendar Round of 52 years.

2018-01-12 16:23 GMT-02:00 Dan Shriver <[hidden email]>:
I looked up the Geneva drive and see that it would solve an unstated problem of mine.  If I used a Geneva drive with one pin and the cross on the underside of the "day of the month" wheel, it would change a continuously turning motion into discrete movement of the day wheel.

I believe you have an idea for how to reset the day but I do not understand it.  Can you provide a diagram of how it works?

Maybe if I have a second cross at the top of the solar month day and there is pin (not sure if it would need to be on a spring or not) on the "month of the year" wheel that causes the "day of the month" wheel to spin back from 5 to 1.  The only problem with that is I would have to somehow disengage the Geneva drive on the bottom...  I'm sure that's not what you are suggesting (since you mentioned "19 pin irregular").  I'm just having trouble imaging what you are saying.

Virus-free. www.avast.com

On Thu, Jan 11, 2018 at 6:38 PM, Ronaldo Persiano <[hidden email]> wrote:
A Geneva drive with irregular 19 pin arrangement?


2018-01-11 20:57 GMT-02:00 Dan Shriver <[hidden email]>:

Are there any clever tricks I could use to reset the day of the month wheel after "Dec 5" so it reads "Jan 1" the next day?

Inline image 1


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Re: Mayan calendar

Ronaldo
Hi, Dan.

I have worked a bit on the idea of using sectional gears to solve your quest about the month wheel in the Mayan Calendar Round. I designed two sectional gears: one for the month wheel and one for the year wheel. The first one has 76 teeth (one for each 5 days) with 7 missing teeth. The year wheel has 73 teeth (one for each 5 days as well) with no missing teeth. The missing teeth of the month gear allow that the wheel rotates 4 times faster them usually during the short month transition. The included animated gif shows the transition of 5 "unlucky days". Another pair of sectional gears would be responsible for this transition (I haven't designed them). The design of the two shown gears is not correct yet because of a small tooth crash at the beginning and ending of the transition but some "light filling" of two teeth of the month gear would solve that.

Animation: MonthTransition.gif
Animation code: mayanSGears.scad
Month gear: monthGear76_7.svg
Year gear: yearGear73.svg

In this design, the two wheels have approximately the same big diameter. I don't see any way to avoid that.


2018-01-12 20:12 GMT-02:00 Ronaldo Persiano <[hidden email]>:
I tried to design my idea but failed: I don't think Geneva drive would do the trick. In fact, I think now a better solution for your quest would be to consider a variable sectional gear mechanism like the one is found in Gearwheels from Hell. Those mechanisms allow to have two or more gear transmission ratio during the rotation. But don't ask how, at least not now. :)



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MonthTransition.gif (545K) Download Attachment
mayanSGears.scad (1K) Download Attachment
monthGear76_7.svg (73K) Download Attachment
yearGear73.svg (79K) Download Attachment
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Re: Mayan calendar

codifies

it might be worth your while to research the antikythera mechanism especially the fractional gears

I never knew you could half a gear tooth... with different ratios with fractions you should be able to reduce the need to have long sectional gears (hopefully)


On 14/01/18 22:11, Ronaldo Persiano wrote:
Hi, Dan.

I have worked a bit on the idea of using sectional gears to solve your
quest about the month wheel in the Mayan Calendar Round. I designed two
sectional gears: one for the month wheel and one for the year wheel. The
first one has 76 teeth (one for each 5 days) with 7 missing teeth. The year
wheel has 73 teeth (one for each 5 days as well) with no missing teeth. The
missing teeth of the month gear allow that the wheel rotates 4 times faster
them usually during the short month transition. The included animated gif
shows the transition of 5 "unlucky days". Another pair of sectional gears
would be responsible for this transition (I haven't designed them). The
design of the two shown gears is not correct yet because of a small tooth
crash at the beginning and ending of the transition but some "light
filling" of two teeth of the month gear would solve that.

Animation: MonthTransition.gif
Animation code: mayanSGears.scad
Month gear: monthGear76_7.svg
Year gear: yearGear73.svg

In this design, the two wheels have approximately the same big diameter. I
don't see any way to avoid that.


2018-01-12 20:12 GMT-02:00 Ronaldo Persiano [hidden email]:

I tried to design my idea but failed: I don't think Geneva drive would do
the trick. In fact, I think now a better solution for your quest would be
to consider a variable sectional gear mechanism like the one is found in Gearwheels
from Hell <http://www.douglas-self.com/MUSEUM/POWER/gear/gear.htm>. Those
mechanisms allow to have two or more gear transmission ratio during the
rotation. But don't ask how, at least not now. :)




      

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Re: Mayan calendar

DanS
Thanks Chris and especially Ronaldo.

I'm still digesting Ronaldo's solution (I confess to being a bit slow about it).

I was wondering about the Antikythera mechanism too (forgot its name, which I should commit to memory as it is the first computer).  Also wondering about old clock that would mechanically put the day of the month.

I'm trying to make the mechanism with as few parts / gears as I can, but also I want to separate the different cycles (day of month, vs month of year)

Virus-free. www.avast.com

On Mon, Jan 15, 2018 at 7:17 AM, Chris Camacho <[hidden email]> wrote:

it might be worth your while to research the antikythera mechanism especially the fractional gears

I never knew you could half a gear tooth... with different ratios with fractions you should be able to reduce the need to have long sectional gears (hopefully)


On 14/01/18 22:11, Ronaldo Persiano wrote:
Hi, Dan.

I have worked a bit on the idea of using sectional gears to solve your
quest about the month wheel in the Mayan Calendar Round. I designed two
sectional gears: one for the month wheel and one for the year wheel. The
first one has 76 teeth (one for each 5 days) with 7 missing teeth. The year
wheel has 73 teeth (one for each 5 days as well) with no missing teeth. The
missing teeth of the month gear allow that the wheel rotates 4 times faster
them usually during the short month transition. The included animated gif
shows the transition of 5 "unlucky days". Another pair of sectional gears
would be responsible for this transition (I haven't designed them). The
design of the two shown gears is not correct yet because of a small tooth
crash at the beginning and ending of the transition but some "light
filling" of two teeth of the month gear would solve that.

Animation: MonthTransition.gif
Animation code: mayanSGears.scad
Month gear: monthGear76_7.svg
Year gear: yearGear73.svg

In this design, the two wheels have approximately the same big diameter. I
don't see any way to avoid that.


2018-01-12 20:12 GMT-02:00 Ronaldo Persiano [hidden email]:

I tried to design my idea but failed: I don't think Geneva drive would do
the trick. In fact, I think now a better solution for your quest would be
to consider a variable sectional gear mechanism like the one is found in Gearwheels
from Hell <http://www.douglas-self.com/MUSEUM/POWER/gear/gear.htm>. Those
mechanisms allow to have two or more gear transmission ratio during the
rotation. But don't ask how, at least not now. :)




      

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