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what is the ultimate machined object/mechanism?

Antikythera rocks

I have to agree with Forrest...

The Antikythera mechanism www.antikythera-mechanism.gr is without peer.

It's a very complex analog computer, implemented entirely using cut gears, to calculate the positions of the planets and determine the date of various events.

It was built over 2000 years ago, a thousand years before that technology appeared in the records of modern civilization.

- Leigh
I'm going with the A-12/SR-71. I watched the one at the museum go together from five truckloads. The machining on the titanium internal stuctures (especially the engine mounts/nacelle main mambers/outer wing pivots are mindboggling. Ditto the solid titanium main landing gear struts. Add to that the incredibly advanced sensors and optical systems they carried.... all basically hand built. To see it sitting in front of you is impressive enough, but to be priveleged to see what lies under the skin makes it absolutely spellbinding.
awesome mechanical achievement

If engines are the choice of focus . My vote would go to the Napier Delta engine . Three crankshafts 3 cylinders per bank , 2 pistons per cylinder , no valves the pistons chased each other up and down the bores uncovering ports like a 2 stroke , with huge centrifugal blowers . if you have seen a Junkers motor with the twin cranks , picture it arranged in a triangle .

But you have to remember they had to park it in a drip pan on the ground because the fuel tanks leaked so badly until the airplane warmed up in flight.
and the special blended fuel they had do develop to cut down on fire issue's while it leaked on the tarmac.

the aluminum powder tires are pretty cool too.

my additions to the list

grown crystalline turbine blades for jet engines that require virtually no machining.

the detroit unit injector, pretty tight tolerances even by todays standards.

also a 2nd for the antikathera mechanism

can you imagine the qualities the builder had to possess?

he had to be a thinker, a mathametician, astrologer, master craftsman, metallurgist, artist, illustrator, and most of all one hell of a salesman (certainly someone that would have given divinci a run for his money)

somebody had to keep him fed, housed, and clothed for the time it took to develop that thing, and convincing someone to pay the freight for something of this caliber would require a hell of a sales pitch in my opinion.

bob g
My vote goes to the anonymous and forgotten guys who machined the core segments for the "Fat Man" atomic bomb. They were machining plutonium, and the parts were:

A) radioactive
B) pyrophoric
C) hard
D) work-hardening
E) poisonous
F) thousands of times more valuable than gold
G) smooth enough to see your reflection in
H) spherical segments

Oh, and it all had to be done on manual equipment, and either with waldos or heavy radiation suits, or both. And nobody had ever done it before, and they wanted the parts, oh, last week would be fine...

I don't know how the Soviets did it either, but I've seen photos of Beria's A-bomb facility. There's a graveyard by one of the shops.

And machined inside an atmosphere of highly poisonous nickel carbonyl gas to nickel plate the surfaces as they were machined: one whiff and you were dead!.
......Re the Antikythera machine et al, Why did it take so long after humanity reached the level to make such a machine before technology really got started?

I have my own views, but will wait for others' before giving mine.


I would want to hear (or read) your views on this.
I think it might have something to do with the state of society around 100 BC versus the state of it at the time we reached the knowhow level again. How the knowledge got lost in the meantime is another question.
I think that in the society of Greece 100 BC mathematics and science was much more highly regarded than it has become since.
injection molds

I've been a machinist for about 20 years now, but never really got into the moldmaking side of things.

Whenever I go down to visit my buddy Marcus Im always very impressed with the plastic injection molds that he builds for various clients.

Im sure most of you guys here on the forum consider that old news, but to the average person thats got no idea what goes into a injection mold. They really are quite the impressive piece a work. All the ground surfaces, and precision workmanship are so sexy....in a toolporn kinda way.

Re: Hubble

... The real tragedy is that it got into space and needed an extremely expensive fix because management decreed that they could not afford to do a final test after assembly on the ground. I'm not even going to make a WAG as to the difference in cost of a ground repair vs running a shuttle mission. ...

On top of that the cost in question was largely an accounting fabrication as the facility to do the test sat unused eight months out of twelve and the Hubble sat completed, ready to fly, from 1986 until 1990. Other tests were done to the Hubble during this period but not a final optical test.
gilds and the lack of a printing press slowed down the flow of information as well.
what little was printed was done by hand, so

when an invading army came in and conquered a new land, the burned the libraries which took out what was printed by hand, and
went around killing all the able bodied men indisciminately so there
could be no opposition later.

hard to sort out the men that knew stuff like science, math and high tech, in the heat of the battle, and there may very well have been a second tier political concern to do away with these men in any event.

the generals didn't need competition for the kings/emperors attention after the battle.

far better to bring back women and children, and a few men with strong backs to be used as slaves as take a chance at bringing back a divinci type that just might dazzle the boss and move you out of your job.

gilds only narrowed the problem for an invading army, probably wasn't hard to determine where such types of folks lived, and make short work of identifying such and laying waste to them for sure.

after all romans had concrete, a compound closely guarded by gilds
and lost to time with the fall of the empire for nearly 2k years. that was concrete, something that was in common use back then. As compared to something like the antikatherim mechanism, which likely was the work of one man and perhaps a couple apprentices. it goes down on a ship and it likely would never be duplicated by that man and his helpers, so its technology was lost forever in practical terms.

makes one wonder what else has been lost, only to be reinvented centuries or millenia later, or what has been lost and waiting to be rediscovered or reinvented.

bob g
My vote goes to the anonymous and forgotten guys who machined the core segments for the "Fat Man" atomic bomb. They were machining plutonium, and the parts were:

Well, I can name one of them. My uncle, Kenneth J. Dunahugh, now deceased. Tapped at enlistment to go straight to the tent city in the desert that would become Los Alamos, and spent his entire career there (another uncle, also a machinist, was sent to the Rock Island arsenal).

If memory serves the trickiest part wasn't machining the plutonium, it was machining the curved sections of high explosive (two different types) that formed concentric shells around the radioactive core. Done in a refrigerated room, very precisely. Very carefully.

-Steve M.
dc lists Gorton's "Lord's prayer on the head of a pin" and someone else commented that such a feat wasn't much. Well, look again, the Gorton technician (Fred Knopp, I think, but not sure of the spelling) engraved the prayer on the point of a pin! They defined the point of a pin as a circle of 0.005 inch diameter. Fellows, this was quite a feat in the days before laser engraving. Even sharpening the pin he used for the drag engraving was quite a task. Lay out a circle at a generous multiple of 0.005 inch and figure out the size of each letter. Makes the Lord's prayer on the head of a pin that you see in the Ripley's places insignificant.

I may be easily impressed, but, in my posession, a group of 25 micro pave'
diamonds measuring 1mm at the girdle, .05 ct, each with a full 57 facets!
No doubt laser cut.
I was also impressed with the story of H4 - the chronometer that was developed in response to a British prize offer (for the first clock accurate enough to use for navigation at sea).

You can see from the variety of posts that it's: anything precision, anything mechanical with enough parts, anything really difficult to machine or assemble, anything with a unique mechanism. Guns. Airplane, rocket, and car engines. Surveyor's tools. Measuring tools of any kind. Scientific equipment. Stuff that causes our eyes to glaze over. It's a madness I tell you!:drool5:
The most humbleing experience of my machining carreer was a trip to the Henry Ford museum in Detroit. That is a building full of "Holy Grails".
have fun
Our community had an old mill with some of the original jacquard loom systems in it. I wanted very badly to get one of two of the card feeders (cards on a string set) for the American Precision Museum.

In 2002 somebody found a new set of Jaquard cards, cut it up into pieces of several cards each and sold them on ebay. I bought one, but from the listings, I don't think he sold many more. I have his name in my checkbook file and may be able to run down his address. My set is currently in the display case in my living room along with the African communication drum and the output tube from the English Chain Home radar system. I have no particular interest in parting with it, but could manage to live out my life without it if it went to a good cause. We should talk.