Antikythera Fragment #11 World’s First Precision Lathe - Constructing The Antikythera Mechanism

Good morning Chris, and welcome back to Clickspring. There are many carefully crafted components within the Antikythera

mechanism

. Retaining pins, for example, must be well formed to fit comfortably within their respective holes. It is the type of work that is most conveniently done by hand. As with a filing block, you can get fairly accurate results with this simple approach using a file with a notch and some wood and perhaps some abrasive stones, the nature of the pegs accommodates this freehand approach some variability in the shape is not only tolerable, but occasionally it might even be. beneficial to the end result for some of the other components the requirements are stricter the

mechanism

s the complex gear train is completely intolerant of friction its many axles and pivots require true cylindrical shapes to avoid jamming the focus is mostly not hand-filed is adequate so, if not essential, then at least a

lathe

of some kind would certainly have been a useful part of the toolkit used to construct the mechanism to which we have clear reference to

lathe

technology in surviving literature of the era, as well as a description of an obvious progenitor that we also know.

We have many turning remains and artifacts, but to date few remains of the actual tools. There is a clear gap in our working knowledge of the lathe technology used to build the Antikythera mechanism, so what was the likely shape of that lathe and How was it? to use it to create functional components for the device in one of the previous videos in this series describing a scorpion and trammel net. I showed that the large circular shapes found in the mechanism can be cut precisely using a simple tool consistent with metalworking technology. of the time, so this leaves only the formation of the small round components, such as shafts and bearings, to be explained.

They are generally quite short and thin, so we are already talking about a relatively small tool. The size of the parts also means that we can rule out any requirement for a pole-operated mechanism. A manually operated bow will provide more than enough motive power. The tool must be able to produce well-finished bearing surfaces to close tolerances and the operator must be able to physically get close to the work to be able to see it well enough to evaluate progress, all of which suggests a tool on the scale of something like this, in my opinion. case I have left the tips on a piece of wood which I can then hold in this work holding device, but they could also be placed directly on the bench or placed on some type of freestanding frame.

The key feature is the opposite points between which the work is rotated for the bow I have used. I used a thin, elastic piece of wood. I have formed a notch on each end in preparation for stringing the bow with a natural gut line. The tool is now reasonably ergonomically shaped, is at a convenient eye level for working from a standing position and once the bow is wrapped around the workpiece, the entire draw will end at normal relaxed arm extension. . The cutting tool support need not be more than a piece of wood or even strips of leather under or adjacent to the working shaft.

I found it helpful to use a few drops of wax to hold things in place. place and still allows the rest to be pushed into the correct position when necessary. The cutting tools are another example of the case-hardened iron cutting tools that I have been using at various points in the construction of the mechanism. Each lathe cutter has been forged and then carbureted using the leather and salt carbon package described in a previous video, once tempered the cutting edges are raised and then continually maintained as the work progresses using abrasive stones. Well, let's take a look at what the tool can do with a piece of wood.

I'm using ebony as a test piece, a wood recorded as being used in furniture construction of the period. A slight cut with a chisel gives a slightly better starting point. for the

first

lathe cuts and two light punch marks are placed in place to catch the centers. A key feature of the lathe is that the two tips are lightly spring-loaded when a workpiece is loaded in the middle, providing the force of closure that keeps it in place; It is convenient to load and then unload the lathe with a small turn and the work comes out in reverse and returns to its place.

If the workpiece is too long or short for the bit spacing, the next hole can be used and, In any position, the tips can be bent slightly inward or outward to modify the closure. force the

first

cuts are interrupted and therefore it is a small stroke to begin with, but the great attribute of the lathe is its ability to boot itself to a more capable state after a slight cut with notches at one end, the work can be repeatedly flipped from one end to the other gradually. By improving the surface gripped by the bow line, line grip is further improved by applying a small amount of rosin to the line, a material I used in a previous video showing its potential role at the time as a soldering flux. gentle.

Then, with a smooth direct drive and reliable grip from the line, real work can begin. In this case, I'm going to do a general reduction of the workpiece and a thin, slightly tapered shaft at one end, the work is now close to being adequate. diameter upon which to mount a metal workpiece using a friction fit, generally speaking the raw metal material is likely to have been cast, forged and then filed into a basic initial shape, from there it can be complete additional initial features, such as an internal orifice, using the pump. drill and hand files as needed once they are close to size, both the shaft and workpiece can be carefully adjusted and then pressed to achieve more spin quite quickly, we finish with another possible tool improvement, the parts of the Bearing are filed as necessary for a perfect fit. adjustment as well as a proper position of the pulley in relation to the pivot point, then once pressed the pulley is captured making sure to leave a small end movement for free movement, so now in addition to the drive method shown above, we now also have an indirect alternative that can be used depending on the requirements of the workpiece in each case, capturing the driving force as best suits the occasion and at the same time taking advantage of the main characteristics of the arc lathe : two pivots, a rotary force, a tool holder and a cutter, an occasional A smear of olive oil on the bearing points helps keep things moving and the cutting progresses in a way that would be familiar to watches and modern watchmakers, because it is basically a crude version of the turns of a watchmaker who used lathe technology to build the first mechanical watches. and clocks, and a precursor to much of what was to come during the era of mechanism construction, this early version of machine technology must surely have been something important to witness.

Our understanding today is that, while its origins are not known, know precisely, it is likely that the art The construction of this type of mechanism was practiced on the island of Rhodes, a naval and commercial power in its own right and a key stopping point for traders in the eastern Mediterranean. Rhodes interacted deeply with the Greeks, Romans, Egyptians and other powers in the region, but ultimately Rhodes. would be established much like Alexandria in Egypt as a center of science and technology where those with the means, such as the Roman nobility, would attend its schools and personal lectures given by highly regarded scholars, among whom were some of the most famous names of ancient astronomy. mathematics, engineering, and philosophy, individuals such as Geminus, the author of an influential student text on astronomy, the "Introduction to Phenomena," Hipparchus, whose astronomical theories appear to support several designed features in the mechanism, and Posidonius, the Stoic philosopher scholar of who Cicero said had built a similar type of device, passing references by Cicero and others to devices and technology that sound similar to the mechanism recovered off the coast of Antikythera lack details to tell us much more than its existence, so today We are left wondering the details of where, who and precisely how this art form was practiced, the mechanism itself providing just enough detail to keep us thinking, asking questions and imagining possible answers.

The bow lathe is a simple tool to manufacture using the tools and materials of the time and is capable of producing all the complexity shown in the remains of the Antikythera mechanism. It is also one of the simplest ways to implement an intrinsic property of our

world

in which a body rotating between two points can have its profile molded true to its axis and thus be transformed into something meaningful from this key principle, everything rest continue thanks for watching, see you later