Version française plus bas -- French version below
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EDIT : Jan 2nd 2016
As asked, I dully documented and published the OpenSCAD file including my optimization.
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This is a cleansed version of the Digital Sundial by @Mojoptix.
The photo shows only the hours tens part.
I found his idea so great that I plunged into his well written and documented OpenSCAD code to understand how it's done.
Then as @BJoe suggested in comments, I modified the code to remove unnecessary bridges (then reducing after print work) and by the way simplifying the stl file.
The two first pictures show a cross section of the third column of the display of the minutes tens digits (the most complicated one). The first picture show the new (cleansed) file.
The sun paths are exactly the same as in original version. Hence the shadows will be exactly the same. And the contrast will even be better during digit transition.
The printing time is 20% shorter.
And the time to manually remove errant strings blocking the light paths should collapse.
All other necessary parts and instructions can be found with the original version:
http://www.thingiverse.com/thing:1068443
Optimization principle : During digits transition, there is no need to block the light for pixels which remain lit.
The third picture (thanks to @stewartde) shows in yellow the parts that can be removed (with no shadow change).
The fourth picture shows the sun movement, and the digit rows.
Here are the way characters are displayed :
Char "0", Char "2", Char "4"
[0,1,1,0], [0,1,1,0], [1,0,0,1],
[1,0,0,1], [1,0,0,1], [1,0,0,1],
[1,0,1,1], [0,0,0,1], [1,0,0,1],
[1,1,0,1], [0,1,1,0], [1,1,1,1],
[1,0,0,1], [1,0,0,0], [0,0,0,1],
[0,1,1,0], [1,1,1,1], [0,0,0,1],
Pixel "1" means that the light will pass, Pixel "0" means that light is blocked by sundial.
The cross section example is cut on the third column.
So let select the third column of the "pixels"
Char "0", Char "2", Char "4"
[1], [1], [0],
[0], [0], [0],
[1], [0], [0],
[0], [1], [1],
[0], [0], [0],
[1], [1], [0],
And the highlight on pictures 3 & 4 are for the 4th row.
Let select the fourth row
Char "0" Char "2" Char "4"
[0], [1], [1],
The sundial for this "pixel" will work like this :
Nolight ("0" doesn't display anithing for this pixel )
Nolight (transition between "0" and "2" )
Light ("2" )
Nolight (transition between "2" and "4" )
Light ("4")
Nolight (transition between "4" and "0" )
Nolight ("0" )
...
There is no need to block the light between the "2" and "4" because the pixel remains lit
So I delete the transition and the sundial works now as follow :
Nolight ("0" doesn't display anithing for this pixel )
Nolight (transition between "0" and "2" )
Light ("2" )
Light ("4") (continued)
Nolight (transition between "4" and "0" )
Nolight ("0" )
...
The sundial display hours from 10 to 16, so there is 6 transitions from "2" to "4" for this pixel (around 10:30, 11:30, 12:30, 13:30, 14:30 and 15:30).
On pictures 3 & 4 you can count the deleted parts : 6 ! That's the right amount !!!
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Voici la version nettoyée du Digital Sundial de @Mojoptix.
La photo ne montre que les dizaines d'heures.
J'ai trouvé son idée tellement géniale que j'ai tout de suite plongé dans le code (très bien écrit et documenté) pour comprendre comment il faisait.
Puis comme @BJoe l'a suggéré dans les commentaires, j'ai modifié le code pour supprimer les ponts inutiles (réduisant le travail post impression) et aussi simplifier le fichier stl.
Les deux premières images montrent une coupe de la troisième colonne d'affichage des dizaines de minutes. La première correspond au fichier nettoyé.
Le passage des rayons lumineux est exactement le même que dans la version originale. Les ombres projetées seront donc exactement les mêmes. Le contraste sera même meilleur durant les transition des chiffres.
Le temps d'impression est réduit de 20%.
Le temps de nettoyage des filoches est réduit drastiquement.
Pour les instructions et autres pièces, voir la présentation de la version originale:
http://www.thingiverse.com/thing:1068443
Margu
