G'day Chris here, and welcome back to Clickspring. Among the many engineering achievements demonstrated within the Antikythera mechanism, is one thats largely hidden from view. And that's the Ancient Greeks ability to create
very precise, small holes. The device is full of them, and they're all critical in one way or another
to its ability to function. To receive locating pins, to act as reliable
bearings for the gearing assemblies, and to form the starting point of the many
square openings found in the various parts. Now the ability to put a small, accurately
sized hole exactly where it needs it to go, is no simple achievement even today. So its worthwhile investigating just how it
could have been done in the Ancient World. The evidence suggests that the vast majority
of the holes in the machine were drilled. And a likely candidate is one of the oldest
drilling tools on record: The Pump Drill. I've designed this version to be a genuine
working tool, with interchangeable drill bits. So it'll need to be durable and robust enough
for daily use. But it will also need to be light and sensitive
enough to cover the full range of holes found within
the mechanism. Where practical, I'm using the raw materials
known to be available in the period, like for example raw copper and tin to make
bronze, and this local oak for the timber components. Where it gets a little difficult to source
authentic materials, or if the material choice has no significant
bearing on the outcome, I've used some modern substitutes. Like for example mild steel as a substitute
for wrought iron, HDPE for the casting pattern, and heavy gauge
fishing line in lieu of a gut based cable. And if you'd like to build one of these for
yourself, the plans are available as a free download, so be sure to check the description box below
for the link. OK, so first up is the flywheel, which I cast
from bronze. Traditionally the pattern for something like
this would be made from timber. But as you can see HDPE is a lot more fun
to turn, and best of all there's no dust to cleanup
afterwards. Now so far in the build I've been using a
modern lathe for all of the turned parts, and of course it raises the question: What
was the equivalent technology of the day? Well certainly there's enough evidence on
the historical record to suggest the widespread existence of turning
technology. In fact the Roman author and engineer Vitruvius, writing at around the time that the mechanism
was lost. Mentions lathes in a completely offhand manner, expecting the reader to be thoroughly familiar
with the idea. As if the technology was so commonplace, that
it barely required explaining. As it happens, the Antikythera Mechanism may
in fact be the very best evidence available to establish the full extent of that lathe
technology, at least as it relates to smaller scale engineering. And its something that I'll be covering in
detail in a later video. OK, so with the pattern complete, I rammed
up a sand mould in preparation for the pour. So thats the mould ready to go, and the crucible is charged with weighed quantities
of tin and copper to give an 85/10 bronze. The remaining 5 percent will be made up with
lead and added once the melt is well established. The pouring basin and gating will be thrown
back into the crucible for the next melt, but the feeder and riser will be used as a
source of round stock for other parts, and you'll see them being used later in the
video. Much like the small parts vise, I think the
"as cast" surface makes a great contrast with the turned surfaces. And you can see that this bronze behaves very
much like a free cutting brass, which makes it perfect for free hand turning. And that's the flywheel complete for the moment. Next up are what I'm calling the collets, The parts of the tool that'll hold the various
drill bits. I cast some long round stock from the same
bronze as the flywheel, and then turned it down to an appropriate
starting diameter. I then formed the basic collet profile. Now the precedent of square drivers operating
in square holes is well established within the mechanism, so I've used the same
idea for this drill design. And whilst I've used the mill to remove the
bulk of the waste stock for the driver squares, this step could easily have been done with
a course file. Much like the process of opening up the internal
square in the flywheel, it just would have required more time and
physical effort. And speaking of which, that's next. Starting with the center hole position, I roughly marked out the square, and then
set about opening it up. OK, so with the major bronze components on
track, its time to have a look at the shaft and drive
handle. The handle is a straightforward profile, and again whilst I've used a modern saw to
save time, its easy to imagine this sort of shape being cut with a simpler
tool. And the same applies to these holes. They're not difficult to form, nor do they
need to be terribly precise. They could be made using the lathe tech of
the day, or even by using much cruder methods like
gouging and then filing. To complete the part, I gave it a light sand,
followed by a linseed oil finish. A bushing will ensure a smooth vertical motion
of the drive handle on the shaft, and it fits neatly inside the diameter of
the feeder that was cut from the flywheel casting. The holes in the shaft were formed on the
lathe. And I've made the shaft as long as possible,
whilst still keeping the overall tool length practical. This'll help to minimise the effect of angular
drift at the top of the tool when its being used. Now the shaft ends would be a weak point of
the tool if not given a simple reinforcement. And that's the purpose of the short ferrules
located at each end. I've formed the ferrules to be a tight fit
over the ends of the shaft, so that although they're firm enough to sit
tightly in place when the tool is in use, they can if required, still be slid off the
end. The shanks of the collets have also been formed
to be a snug fit inside the shaft. But they need to be a cross drilled, along
with the receiving end of the shaft, to accept a retaining/drive pin. The drive pin as a sort of thumb pin, that
can be easily inserted and removed by hand. The other end of the tool of course needs
to be supported whilst in operation. So I've designed it to have a free rotating
knob. Now you may have noticed that I've used a
shop made drill bit for the last few drilling operations. This type of drill bit is incredibly effective
at forming small precise holes. And was being used by clock makers for many
hundreds of years prior to the invention of the modern twist
drill. Its quite possible that its use extends all
of the way back to antiquity, so its a reasonable candidate for the sort
of drill bit used to construct the AM. I've created a separate video showing a process
that could plausibly have been used to make this type of drill bit, so be sure
to check out that video. In any event, once created, the drill bits
themselves can then be used to drill out the collets. Each of the 3 test bits correspond to a critical
feature found within the mechanism. One is for a standard bearing hole, one for
a standard retaining pin, and the smallest, coming in at just 0.8 of
a mm, corresponds with the holes used to locate
the calendar ring. Now there is evidence of the use of soft solder
within the mechanism wreckage, and certainly soft solder would be suitable
to hold the bits in their collets. But equally plausible, and I think a little
more convenient, is resin. I'm using shellac, but any hard resin available
at the time would have worked well. The bit is solidly held, yet a gentle heat
can be used to soften the bond. And permit the bit to be replaced, or extended
for sharpening as it wears out. The driving line needs to be securely fastened. And since this part of the tool is under considerable
strain, I've turned up a couple of tie off rings to
ensure both a good solid hold on the cable, and a modest distribution of the load around
the hole. And with that, the tool is complete, so lets
give it a test. Its interesting to see that the same practices
that apply to modern drilling, also apply to this tool. A center punch mark is essential to ensure
that the hole ends up where it should be. A few light turns with the drill, are enough
to gently open up a good starting point. And of course the entire drill pivots on that
drill tip. So it has a strong tendency to follow the
marked position. The driving action is quite straightforward. It doesn't take a lot of effort, just a consistent
force to keep the flywheel moving. Although it does take a bit of concentration
to keep the tool upright. Its easy to let the angle drift a little,
and so risk wallowing the hole. The concept of using a pilot hole also transfers. The larger bit will cut through on its own, but its much easier to pilot the hole first
with a smaller bit, and then follow with the larger bit. Now one thing the tool needs, is the ability
to be able to vary its inertia and downforce, as the circumstances change. So I made some extra flywheels of different
sizes to give it that flexibility. The larger flywheel, helps overcome the cutting
forces experienced by the larger bits. And the smaller flywheel gives the tool more
sensitivity for the smaller holes. And its certainly a very practical tool to
use. The changeout of drill bits and flywheels
is fast and easy, and the drilling time is comparable to a modern
drill. Now as to whether or not this type of tool
was used to build the mechanism, well who knows. But I do think its fair to say that its a
contender. These test pieces compare well with the holes found throughout the wreckage of the mechanism. And certainly there's no doubt that the tool
is capable of making holes to at least that standard. I'll continue to experiment with it, and we'll see how it performs throughout the
rest of the project. Thanks for watching, I'll see you later. Now if you enjoyed this video, and you'd like to help me make more, then consider becoming a Clickspring Patron. As a patron of the Channel, you get immediate access to the Patron Series
of videos. This includes the 5 videos of the Wedge Style
hand Vise Project, and at present the first 7 videos of the Byzantine
Sundial Calendar Build. There's also the first 4 episodes of the new
Tools Glorious Tools series, with more to come as that series progresses. In the most recent episode, I go through the things to consider when setting
up your own home shop. And don't forget that as a patron you also
get free access to the plans for the Patron Series projects. So you can follow along, and build them yourself
if you wish. Visit Patreon.com/clickspring to find out
more. Thanks again for watching, I'll catch you
on the next video.
even Chris's casting molds are a work of art
Clickspring is such a badass, I am an unapologetic fanboy.
Stupid question... Did he make a casting mold for the flywheel because there was no block of the metal he wanted to make it out of (bronze I think?) to make/put on the lathe?
Mesmerizing
yay, i knew it had to come out one of these days. And two videos in one week no less
I wish there was a way for a normal person to make a living doing this. All I want to do is make cool shit but the starting costs (equipment, space and materials) and education required are crazy. Oh well, I’ll be dreaming from my local maker space.