Update June 2015: I’m revisiting this project to finally get it to a version where it can be manufactured at home. Check greekgears.com for future updates. I have also withdrawn the files and re-released them under a similar noncommercial license.
Update June 2016: Haven’t forgotten about this project, but I’m back in grad school so free time is limited. I’ve gotten it to a point where I’ll need a laser cutter to test out design options, so things are pending me finding one I can get.
By request, I’m making the CAD files for the model of the Antikythera Mechanism that I created freely available. (Click that link for an overview of the project.)
Download the Antikythera Mechanism from Google Drive here. You’ll need Solidworks to open it, and 3D PRINTING WILL PROBABLY NOT WORK. I’ve gotten asked that a lot.
It isn’t perfect. There are a few issues that would keep it from working if you 3D printed this, and a few more issues that make it not completely authentic to the original Mechanism. Here are the places where the model differs from the Antikythera Mechanism. Italicized issues keep it from working if it was 3D printed. I estimate it would take me 40-50 hours to fix them (it would require a redo of a lot of parts), which I don’t really have time for right now. But… if someone had access to a 3D printer and would print me a copy pro bono, I might be motivated enough to clean it up.
- All gears except for the lunar phase geartrain are assumed to have a module of 0.5. This is actually the mean value of the modules for all gears in the Mechanism. A more accurate model would account for variations in the gears. In one instance, this creates a collision between a gear and a support as it travels around. A few gears should also be thicker.
- I didn’t use values for the pin placement radii on the epicycle gears. These can be found in Freeth and Jones’ “The Cosmos in the Antikythera Mechanism.”
- Two indicators should slide onto the Metonic and Saros pointers, and track in the engraved spiral on the back face. Solidworks had issues with a tangent relationship to a spiral, so these are suppressed in the model (but are still there!).
- The Antikythera Mechanism used a combination of adhesives, pins, and friction fits as fasteners. The model uses no fasteners, and would need a few if printed. All the gears that need to have locked rotations are keyed and spaced out with spacers, but some of the keys are really small loose pieces and should be changed.
- There are no tolerances built into this model.
- The Antikythera Mechanism used triangular teeth. The model uses involute profiles. Solidworks was having issues creating these profiles in a couple cases, and a few gears don’t mesh correctly.
- The wooden frame, pointers, and posts are creative interpretations. The large pointers should be removable in the real model to allow the indicators to reset.
- The planet positions are not zeroed to any celestial day.
Despite these differences, the form, function, and essence of the Antikythera Mechanism remain intact.
Also, some licensing info!
I am releasing this to the public under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence. This is a mouthful, but it basically means that you are free to use, edit, and redistribute these files so long as you a) credit me for originally making them, b) don’t use them to make money, and c) apply the same license whenever you redistribute it. This means they will be forever free. With the following exceptions!
- The files “plate back lower dial v4.png” and “plate back upper dial v4.png” are taken from Freeth et al. “Calendars with Olympiad and Eclipse Prediction on the Antikythera Mechanism: Supplementary Notes”, and slightly edited by me. Copyright belongs to original owners, however because it is a published paper all educational uses are fair use.
- The file “plate front v2.png” is taken from this image, originally made by J. Evans and A. Thorndike, and edited by me. Copyright belongs to original owners. (They might mind if you use it educationally. I doubt it though.)