The Antikythera Mechanism Episode 8 - Making The Mean Lunar Sidereal Train

Its so awesome to see the work in its original form isn't it. I love seeing the text just leap out of the darkness in some of them!

Clickspring

G'day Chris, Just watched this video again and decided to follow the CT and PTM data link you put in the description. Wow. Watched a couple of the CT scan videos frame by frame. It was fascinating seeing the original features (such as the pentagonal fitting for one of the wheels, one of the 'horse head' pins and boss it went through, a taper pin or two through arbours holding wheels in place, etc, etc), that you have been labouriously demonstrating in the videos. As you have shown excerpts from these, I wasn't sure how interesting it would be watching them again, but it was entirely different being in control, frame by frame, and being able to 'home in' on specific details. Thanks for the link. Cheers

Duncan Luddite

Chris, did I miss something?? Do we know any of the original cities ?? Rotted away I suppose. But would not the original only have places in the word that they knew?? Just something to think about, yea like you don't have enough.

Ralph McCoy

Not at present Mark, my main focus is making the videos and developing new projects - Cheers :)

Clickspring

Do you take commissions or are you simply a hobbyist?

Stubbs

Thank you mate - stay tuned to the AM build :)

Clickspring

Ha ha! Still a long way to go :)

Clickspring

Hey, I absolutely LOVE your work, if i could, I'd commission you to do something if I had the money. I LOVED watching you make that small skeletal clock(forgive me, I have forgotten the exact name of that type and style of clock.) It was like a 24pt vid series. I just got done watching an orrery made in 7min time lapse. And as cool as it was, I couldn't help but think of you. So i guess I kinda challenge you to make one after the antikythera device, if you haven't already made an orrery ;)

Justin Densmore

Really, you haven't got this thing finished yet? Come on mate, what are you doing with your time? Yes, okay, you're hand-fabricating every single part and going into an incredible amount of detail about the means of doing so, but seriously... I want to see it working, get a move on! ;)

Chris Talbot

Ha ha! Awesome mate! Its a terrific book, covers everything so well. Agree with your following points - The visual acuity thing in particular is so interesting isn't it? There are so many subtle implications in just that single observation.

Clickspring

Another great video, and well worth the wait. :) The next one on the pin-and-slot mechanism for the lunar anomaly is the video I have been hanging out for. That is the most impressive part of the mechanism design. I am just coming to the end of the 'Hidden Workings' section of Alexander Jones' book 'A Portable Cosmos', which includes a discussion of that part of the AM. So I am ready to go for that video! (I bought the book on your recommendation, Chris, and can highly recommend it to others.) ——————— "you'll have noticed that the wheels and pinions of the mechanism are quite thin, in most cases between 1-2mm thick" That is very impressive when done by hand, and without the benefit of magnification. Pretty safe bet that the craftsmen doing the actual detailed work on the original were no older than about 35-40, when their eyesight was still sharp. It is easy to forget the scale you are working on due to the high quality close-up video shots. Even more so when playing the video on a large screen, where the shots can take on an almost cathedral perspective. It is only when one of your fingers or a ruler pops into the picture that we are reminded of the true scale. The thinness also means that much of the internal mechanism would be relatively fragile. We have been very lucky that as much of it survived as did. Certainly enough to figure out the basic device. ——————— On the increased friction penalty of the supporting kerbs. I am guessing that would be reduced considerably if the mechanism is operated in a vertical orientation, which would make the kerbs more constraining guides than direct supports.

Sean Kirby

Sounds like fun, I'd enjoy that :)

Clickspring

Yes the plans will be available at the completion of the build - Cheers :)

Clickspring

Yes always plenty of mistakes, prototyping and testing - Plenty of parts that either didn't make the grade, or were just a step on the learning curve - the soldering vid is a good example. I had a rough idea of how I thought it was done based on the scan but it required a fair bit of testing to get the block mass correct, and then a lot of time to learn how to use the tools properly - it was like learning to ride a bike for the first time, very messy at the start!

Clickspring

Cheers Stefan :)

Clickspring

Thank you! - Possibly, a bit more detail in my answer to Gareth 2 above - Cheers :)

Clickspring

When the project is done do you think it would be possible to reach out to the people at Hublot about their Antikythera movement watch? I think it would be really interesting if you were able to sit down with one of the watch designers that also worked with the mechanism and discuss the differences between their modern approach and your very traditional approach to the same mechanism. Great stuff as always

I was wondering if I could download the plans for the Antikythera Mechanism you are creating I would love to create a 3D model of the device.

Ken Hilke

I love seeing that main plate get more and more populated! I have a question about making mistakes. Basically do you ever make any? Is there a box kicking around your shop of failed attempts at antikythera mechanism parts?

DP Make Stuff

Absolutely brilliant! Your attention to detail is a huge inspiration :)

Stefan

Great video! Is there some advantage of soft solder over pins and vice versa? Or would there be some other reason to use two different fabrication methods for parts that serve the same function?

Karolus

Thank you Mike :)

Clickspring

Another great video showing off your masterful skills. I cannot wait for the next one.

Mike oliver

I'm so pleased you're enjoying them mate :) Great question on the kerbs, and at present I really don't have a good explanation - Its possible that the kerbs were made from scrap offcut stock, so the Maker had to work with what was available. If that was the case, then my best guess at present is that the thicker stock was pinned because it was easy enough to drop in holes for the pins, whilst the thinner stock was soldered due to it being more difficult to fit a reasonable sized pin in the thinner metal. The broader 'C' shaped kerb under the D assembly is the one that rather messes with my theory because there's ample room to pin it rather than solder. Personally I think it was harder to solder than pin, so that's a choice not made lightly. An additional piece of information that may help answer the issue: The two additional kerbs under B1 (that I have yet to fasten) I think are probably adjustment kerbs that lifted the B assembly slightly higher to correct a fitting problem encountered once the planetarium structure was in progress - ie the original 2 were probably found to be slightly short. So it may also be due to the sequence of the events of the construction. In any event I'm keeping an open mind :)

Clickspring

Hi Chris. First off I'd just like to say I absolutely love your videos. I have a small home workshop myself all be it with older equipment (e.g. my lathe is a Drummond B type and around 100 years old). I certainly do not have your skill or experience though, and watching you turn stock metal into expertly crafted mechanical components is such a joy. You mentioned that the fixing method for the kerbs varies, with some of them being pinned and some of them being soft soldered. Is there any indication as to why this might be? Has making this part of the mechanism given any insight into what the original maker might have been thinking and what drove his decisions with regard to these two fixing methods?

Gareth Eldrett

Thank you mate :)

Clickspring

Your work is still amazing, the ancient Greek would be proud to see your recreation. I know a bit about flux but didn't know how zinc chloride came about or how old it's formula is..... rosin I know quite well. Always learning something from your video's, just what I like to do Cheers Chris, you never fail to give me a moment of inspiration or drive

Matthew Sykes

Thank you mate!

Clickspring

I would guess to minimise the friction with the underside of the D assembly, but equally it could have been an aesthetic choice - Cheers :)

Clickspring

What is the point of the dome on top of the stud for the C assembly?

A1BASE

As usual Chris, just WOW! Wow wow wow!

Hey Tom, here is a good shot of a modern pivot profile: <a href="https://youtu.be/Yt20qj1DHpc?t=5m7s" rel="nofollow noopener" target="_blank">https://youtu.be/Yt20qj1DHpc?t=5m7s</a> - The shoulder is the part that I put the last chamfer on. The slight rattle (longitudinally) of the wheel assembly when its assembled within the frames is known as 'end shake' and is basically just a clearance margin to keep the whole thing free running as the clock frames flex under load (and to allow for small errors in manufacture!). For the AM a very similar outcome was achieved where it mattered the most (under high load), using that proto bridge/thrust plate idea - Cheers :)

Clickspring

Thank you mate! The wreckage is a mess from the corrosion, but it carries some strong implications that have become clearer to me as the build has progressed. For example I've become convinced that abrasives like pumice, used on an otherwise flat surface (which we know from many other sources they could make in abundance) are the key to much of the mechanisms construction. Its a very simple way to set the incredibly close clearances required for the mechanism to function, and simultaneously be so compact - from preparing the raw stock, to the plates, wheels and spacer discs, I think basically most of the key components were 'fitted' using a flat hard surface plate (obsidian? granite?) and fine abrasives. This could be further extrapolated to perhaps imply a more structured approach, but at a minimum simply observing a daylight clearance of a thou or two would have done the trick, as per this sort of thing: <a href="https://youtu.be/vDYnxxUV4Nk?t=19m57s" rel="nofollow noopener" target="_blank">https://youtu.be/vDYnxxUV4Nk?t=19m57s</a>

Clickspring

What do you mean by "limiting endshake on a pivot shoulder?" Also, what is a pivot shoulder ? Google turns up some very technical clockmaking books but nothing that explains what it is.

Tom Dunbar

Amazing videos as always, Chris! One thing that got me thinking. In the soldering video, your hammering obliquely implies a critical problem the original maker must have faced, particularly with the large main plates: How to repeatable obtain flat, parallel surfaces. It almost suggests some knowledge of surface plates, and the necessary knowledge of three-plate ablation. Have you (or others in the literature) given any time to this problem? Or, are there errors in the original plates which suggest specific limitations in the ancient knowledge on this subject?

The really weird thing is that I still find new features almost every time I look at them - amazing machine

Clickspring

I'm looking through the CT scans and am blown away as how you can pull this level of detail out of them. But sure enough, I can now see the little ramp in the gear to fit the pin. And sure enough, the stabilizer ribs for the larger gears are right there. Your videos on Youtube are the only ones I'll watch five or six times.

Kevin Reardon

Cheers :)

Clickspring

Cheers mate :)

Clickspring

It was really bugging me that it fell through with such a thunk :)

Clickspring

Nice idea with the drop stop on the pump drill.

Samuel Irons

And now I know why they used the square and hexagon in the drives. I had thought there was some mystic reason as those shapes were special in their model of the Universe. They were used because of the load on those particular gears. Thanks mate.

Kevin Reardon

Gday Chris TFS. Can't wait for you to finish as then I'll be able to binge watch all episodes :) All the best mate G.

Graeme Brumfitt

Love the history. Miss the machining. Can’t wait for all that is to come.

Kirk Jensen

Brilliant again Chris. Really think the filming and editing was even better in this video. I am not sure I will stop being amazed at watching you peen and file 2 pieces of brass to look like one. How are you finding the pump drill? Do you think about throwing it up on the drill / mill press or is the time difference between the 2 small enough to make it worth while?

Paul Busby

What an awesome way to wake up, coffee and Clickspring Can't wait to see this all come together, keep up the good work!

Clifton Ballad

Its a really interesting issue Gary - no evidence remains in the original, but I'm experimenting to see what might have worked. I'll cover it in detail when I've tested out a few more ideas, but Its a very different machine to what we would normally encounter, with extremely large surface areas interacting that encourage lubricant spread, and therefore the negative effects of surface tension. So thus far it appears to me that it was run dry, but I will keep you posted as I learn more about its behavior - Cheers :)

Clickspring

Will do mate, thank you :)

Clickspring

This will be given a much more rugged finish, which I figure is more consistent with what the original would have had - its a fairly austere device when you get down to it. Having said that, there will be an opportunity for some nice contrast, with maybe a high grade pumice finish to a few select items to make them pop out a bit. There's also a suggestion in recent research that pewter was used, perhaps for adornment - Cheers :)

Clickspring

There's not a whole lot more to show Alan, just bend them to shape either by hand as shown in this vid with the longer thin ones, and add a bit of gently peening for the thicker ones - Cheers :)

Clickspring

i always look forward to your videos, please keep it up

daniel poole

Hi Chris. Another fascinating video. You talked about the friction penalty of the various assemblies. Made me wonder if they used lubricants of some form. I was going to say that there would be no archaeological trace but tallows and other fats do have interesting decomposition chemistry that could leave traces on the metal. After a few thousand years on the sea bed I doubt, even if it was there, that one could be sure of it's origin. Many thanks for this amazing work. Gary

Gary Knight

Hey Hey! Thanks for this new one :) Question : Are you planning to make a mirror finish on all these pieces like you did on the Skeleton Clock ?

Ludovic MOUROUVIN

Another fantastic video, thank Chris. Are you going to show the process you used to make the curved supports in another video?

Alan Budden

Thank you mate - here is a video showing the profile of a modern shouldered pivot: <a href="https://youtu.be/Yt20qj1DHpc?t=5m7s" rel="nofollow noopener" target="_blank">https://youtu.be/Yt20qj1DHpc?t=5m7s</a> its such a simple technological change, but the change to the friction profile is dramatic - Cheers :)

Clickspring

Exceptional video, thanks for the many insights. Would liked to have seen an image of the modern attributes (shoulder, etc) you mentioned to put the Antikythera mechanism constructs into perspective.

Gregor Shapiro

Cheers Derek :)

Clickspring

Thank you mate :)

Clickspring

Hey Ralph - Its all pretty much corrosion byproducts holding it together now, so it wouldn't be accurate to say that its still soldered. In fact a few bits and pieces have been falling off over the years, and my understanding is that several have been CA glued back into position!

Clickspring

Ha ha! Cheers Sam :)

Clickspring

Another fascinating video. Thanks for sharing this with us!

Derek Meisenhelder

Chris, beautiful work and excellent work on the history of the mechanism. I hope to reach your level of craftsmanship, I am trying.

Glen Simpson

Curves not pins

Ralph McCoy

Chris, you said that some of the pins were pinned or soft soldered, does that suggest that the one that was found in the sea was still soldered after 2070 years ago. Ralph

Ralph McCoy

I ditched my date because I got an e-mail saying a new TAM video was available to Patrons. I hope she enjoys the rest of the movie.

Sam Oldman

Awesome mate, so pleased :)

Clickspring

Perfect ending to the day while sipping some good whiskey. Thanks Chris :-)

Chris Muncy

My brain hurts too!

Clickspring

Good lord, I think my brain hurts now ... (looks at recent machining project) ... and also my pride ;-)

Martin Anderson

Thank you mate :)

Clickspring

I'm in awe every time I watch one of your videos. Well done. Cannot wait until the finished product.

Richard Thompson