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what is the ultimate machined object/mechanism?

Maybe the ultimate analog computer would be the Mk. 38, fire control system on the Iowa class battleships.

Inputs would be: range, bearing, ship speed, enemy speed, temperature,humidity,Barrel wear, Coriolis effect, type of projectile, etc.

All computed by cams and gears.
 
The Hubble mirror. Polished to >10nm accuracy. There's also lots of examples in Nasa's machine shops.

To the wrong focal length.

The Babbage computers have to be on the list, even though Babbage himself never managed to make more than single digit demonstrators. Some Limeys CNC milled the machines now in existance, and even with modern accuracy, it wasn't a cakewalk.

Bill
 
I've ponied this one up before: The mechanical fuel computers used on first-generation turbojet engines. Some of the most complicated mechanical devices made, using golfball sized 3-dimensional cams to compensate for temperature, rpm, throttle position, fuel temperature, air temperature, engine pressures, and so on. These first-generation turbojet engines were incredibly finickey about handling, opening the throttle too fast or too slow could melt down the turbine blades, etc.

If not that, then the Whittle or the Jumo turbojet engines of the late 30's early 40's. Whittle eventually became the centrifigal flow engines (like the PT-6), while the Jumo became the axial flow engines attached to every jetliner.
 
I was thinking about the "holy grails" of the mechanical world, the objects that represent the application of tremendous machining skills, tools and inventiveness. My personal ones include the Norden bomb sight, the Lord's prayer engraved on the head of a pin by the Gorton Co., a C.E.J. Mikrokator that measures to a millionth of an inch, the Harrison chronometer and some of the chiming mechanisms being developed by the Long Now foundation. I realize that these are only a few of the amazing devices that have been produced by the best in our field so I was hoping that people might help to compile a selection of what they believe to be the most fabulous mechanical objects or machined parts. I would also love to know what makes that object so special to them. This could really draw on the diversity of the PM community. Please let me know what you think.
Great proposal DC.
As you anticipated, it should bring out a wonderous variety of inspiring devices and has already!
It will only be human nature to ignore, "the objects that represent the application of tremendous machining skills, tools and inventiveness." and to rewrite what you really meant, to fit their interest, so be it, even more interesting.

John in CA picked a most favored one of mine, "The Newbould Indexer". Because of micro machining or mind numbing complexity? Quite the opposite, because of the simplicity of a device of such elegant function, while being well within the realm of skillful machine work to produce. A remarkable example of the rarified* class, "multiplier of precision" and indicative of truly inspired imagineering. Devining an elemental truth that lay hidden until the 20th century.
*As an example, most instruments of metrology introduce further opportunity for error in defining precision. Even such phenoms as optical flats, only reduce error, never crossing the the line to the "multiply precision" side.

A less elegant but good example of a multiplier of precision, the dividing head with the ability to refine it's own precision in multiple passes, rather than to degrade it as is the norm in copy of a copy.

Even the dividing head falls short of rj's magic. The dividing head can improve it's own precision but falls short of intrinsically providing that benefit to another, except for the secondary improvement of being of higher precision as a result.

Bob
 
As I recall from reading an article on the building of the Babbage Difference Engine they found several errors in the original design. Had Babbage actually built it they were sure he would have discovered them also, and corrected them.

-DU-
 
I also have to add compensating polar planimeters. Some of the simplest devices made, a couple of pages of math to describe their function.

Bill
 
To the wrong focal length.
Bill

Well, sure Bill, if you're gonna quibble. :) This really goes to show you that keeping the goal in mind, and using feedback on complex processes are necessary ingredients in complex projects. A simple Foucault edge test would have revealed the flaw!!!

Which begs the point: is the OP searching for the most complex and wonderful systems produced by a group? Or the coolest thing produced by a single human or small group?

I think some of the new big terrestrial telescopes, with multiple mirrors and active optics, are pretty cool.

Jim
 
I've ponied this one up before: The mechanical fuel computers used on first-generation turbojet engines. Some of the most complicated mechanical devices made, using golfball sized 3-dimensional cams to compensate for temperature, rpm, throttle position, fuel temperature, air temperature, engine pressures, and so on. These first-generation turbojet engines were incredibly finickey about handling, opening the throttle too fast or too slow could melt down the turbine blades, etc.

If not that, then the Whittle or the Jumo turbojet engines of the late 30's early 40's. Whittle eventually became the centrifigal flow engines (like the PT-6), while the Jumo became the axial flow engines attached to every jetliner.

There are still alot of plane flying with this 3-d cam technology. 737-300s and F-16's, B1 bombers just to name a few. The prototype 3-D cams were machined on manual jig borers.

I work for a company that makes jet engine fuel controls.
 
One of my favorites is the Spica mechanical fuel injection used on USA market Alfa Romeos in the late 60s- early 70s. Uses a 3d cam and compensating mechanisms to compute the fuel metering based on throttle positon, engine RPM, engine temperature and barometic pressure.

Also, ever seen one of the original Jaquard looms? There is one (or maybe a copy) in the museum in Edinbugh, Scotland. I think the Jaquard looms are considered the first programmable devices. The patterns where programmed using punched cards or boards.

How about the humble sewing machine? Pretty amazing things, really

Rich
 
geez, some of you guys beat me to some of my favorites, so please forgive any duplications..... in no particular order (and certainly not limited to):

the Newbould indexer
Saturn V
SSBN subs (the silent propellers in particular)
the rangefinder on Iowa-class battleships (the rest of the ship as well)
nuclear aircraft carriers
messerschmidt Me-262
the stealth bomber and fighter
the SR71 Blackbird
the injectors in my F-350 (running on 20k psi oil pressure)
pretty much anything from the mind(s) of Igor Sikorsky, NASA, the Manhatten Project, Lockheed's Skunkworks, Nikolai Tesla....

the list could go on indefinately!
 
Well, sure Bill, if you're gonna quibble. :) This really goes to show you that keeping the goal in mind, and using feedback on complex processes are necessary ingredients in complex projects. A simple Foucault edge test would have revealed the flaw!!!Jim

The guy in charge just plain screwed up and set the instrument wrong. 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. The good side is that the mirror makers preserved the settings on their instruments so they knew exactly what the error was and could make the best possible correction. The rest is history- a lot of history.

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.

Bill
 
The rest is history- a lot of history.

I saw on TV last night (Nat Geo?) that the current shuttle mission is bringing back the device that effected the repair - the new optics available and being installed this time make it unnecessary. The engineer that developed it is getting it back to display in his office.
 
I would have to say the Apollo 11 lunar lander, Command module and Saturn Five rocket, the whole assembly top to bottom including the space suits. All machining done with what we would call primative tape or even card feed NC machines and manual machines, new materials never tried before, methods with no real room to try in the field but for simulations, and a lunar lander with no real "lunar testing" in lunar conditions other than a fly by. Every machined or mechanical part eithar fabricated, machined, or cast/poured to standards we require today. Composites that were new, electronic parts and printed circuit boards that were generations ahead of their time that set the standards of what we call normal today. Fabrics that were new and had to be produced in ways that could never be done before.

In its day this was an item that was at least 20 years ahead of its time in all aspects made on machines perhaps right at or behind the times.

What makes it all the more impressive is the shear number of subcontractors working on "secret items' at that time, having to make one to five offs that had to fit exactly with other parts made by thousands of other subcontractors. That this was a pile of parts made by the lowest bidder in many cases makes it all the more impressive.

There was no room for error, leaks of air from the capsule to space, or for electronic misfunction. The landing gear had to function the first time, no testing could be done for the "real deal".

Only one misfire after the Apollo 11 flight, a small electronic part and the mechanicals and computers held out to bring the people home.

I have heard that the skin between the LEM and the moon "atmosphere" (or lack thereof - space) was .008 thick, but the engineering made it as strong as any steel car plate.

The parts themsleves may not be completely impresive by today's standards, or even matching them with some of the great "artworks" like the lords prayer on the head of a pin (I have seen this, it is impressive) or the Mauser, a work of art for its genere, or perhaps my old orvis fly reel that I believe is a true piece of art in simplicity and design. The Apollo 11 mechanism is perhaps the peak of what could be done with a mechanism for its time - actually well ahead of its time. It also changed manufacturing, machining, engineering, electronics as well. Beyond the parts were the simple facts of having to develop new methods, technologies and materials to make this a go. Things like Velcro, new cutting tools, new metal alloys, weaving technologies for fabrics, bearings, microcircuits becoming a new standard.......

Rich,

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. I asked for a set of the cards and a reader from the person and he said "fine", but when I went back his workers had pulled the reader and the loom out of the building and carted it away for scrap. There was one that I have pics of somewhere that was intact with the whole rack of cards to make a simple shirt "tag". What a horrible loss, I never even had a chance to call the AM. Precision as it was December, nor did I have the room to store the whole thing (nor way to move it) at the time. THIS was an amazing piece of technology!!!!!
 








 
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