the first flat surface???

[kye]

hello all,

this is a question that ive pondered to myself on and off for quite a while, never really ever finding a reasonable answer.
basically how was the first truly flat surface/edge made?
ive come up many ways in which i COULD be done, but there always seem to be some small level of inaccuracies that i can think of for that given method.

anyway would love to here peoples ideas/theories/the way it really was done etc etc

 

[b.lindsey]

Good question and my guess it that two pieces of similar hardness and relative initial flatness (probably rocks like sandstone) were worked back and forth against each other until the high and low spots were diminished and until the two pieces mated seamlessly, this then being used as a reference similar to what we now know of as a surface plate. Just a guess, so will be interested in other theories.

Bill

 

[arnoldb]

The most popular method IMHO would be the "Three piece" one - where three nearly flat workpieces are lapped together through a series of rotations - Piece 1 & 2, then 2 & 3 then 3 & 1 - and the process repeated until the necessary degree of "flatness" is obtained.

I don't think anything can be made "truly" flat - only "flat enough for a certain use", that is why things like surface plates usually have a tolerance associated with them, and why you pay more for the higher accuracy ones. Even if things could be lapped down to molecular level, true flatness cannot be obtained properly, because of the way the molecules combine to form a certain material.

My useless N$0.02

Kind regards, Arnold

 

[velocette]

Hi You can click on this link

http://en.wikipedia.org/wiki/Joseph_Whitworth#Accuracy_and_standardisation

This is a man who gave us many of the engineering standards and fitting

Google "Joseph Whitworth" and have a browse

Hope this helps Eric

 

[lazylathe]

Just to throw a rather large spanner in the works.... ;D

I offer this:
http://en.wikipedia.org/wiki/Pumapunku

Stuff like this has always fascinated me.
I especially like the blind holes with complex shapes and flat bottoms!

If anyone can explain how they could do that all those years ago?
To achieve the same results today we would need to build immense, complicated machines to try and replicate their results!

Makes you think, doesn't it?? scratch.gif

Andrew

 

[b.lindsey]

"Ancient Aliens" perhaps :big:

 

[90LX_Notch]

Andrew-

I would chalk it up to lost knowledge/technique. Look at what the old time machinists accomplished. If it weren't for old books explaining how they did it, I'm sure people would say that it was aliens. After all, they didn't have modern CNCs. Therefore, it would have been impossible to accomplish what they did according to some people. But, they sure as hell did it.

-Bob

 

[lazylathe]

But machinists had machines! ;D

Some of those ruins are more than 2000 years old.
Add into the equation moving 100 ton blocks of solid stone over 100Km's and it gets even more interesting!

And then some of the blocks do not have any marks on them from tools.
Weird!!!

Somethings we are not supposed to know!
(play x-files music now...) :big:

Andrew

 

[Ken I]

As Arnold said the "3 Block Method"

Issac Newton used this method to produce optical grade flats - that's flat to fractions of a wavelength of light

or Angstrom Å 1 Å = 0.0000001mm

Ken

 

[mklotz]

A few things to remember when reflecting on the seemingly impossible accomplishments of ancient societies...

None of any complex tools/scaffolding made of wood, fiber, or earth will have survived.

High value tools such as core drills or chisels will have been carried off to the next job and/or used up by wear and resharpening. Our chances of finding such artifacts or identifying the remains once found is very small.

Mistakes will have been ritually destroyed or recycled. We see only the end product, not the sequence of mistakes that led to it.

 

[Mainer]

Whitworth did it with three square plates, scraped such that any two could be spotted together in any orientation.
It takes 3 plates, otherwise you can end up with the equivalent of a very large radius ball and socket.

See if you can get a copy of "Foundations of Mechanical Accuracy" by Wayne R, Moore (of Moore Special Tool Co.) from the library. It goes into detail about establishing basic references like a flat surface. Moore still sells it, but it's $150. The cheapest used copy available through Amazon is $260 (go figure).

 

[arnoldb]

Going O.T. from the original post..., But it IS the break room

I have to agree with Marv and others.

In modern civilization we tend to forget all the "basic" methods, and we tend to think in terms of what we have "now".

The ancient South American civilizations had quite a selection of resources at their disposal - and they had a fairly good understanding (for that time) of metallurgy - they invented "trick gold" long before recent alchemists started contemplating "making" gold.

One thing that puzzles me, is the fact that rubber is not mentioned more often in their doings; I can scarcely believe that such a usable material would have been overlooked in their engineering endeavors - other than for making into balls to amuse themselves.

OK - Now I'm wildly speculating, probably fanciful, but then, nothing's impossible...
It's mentioned that they understood hydraulics, and this may seem far-fetched, but I think it's quite possible that they would have used rubber to help make water-tight vessels to be able to use hydraulics to their advantage - for lifting and moving heavy things.
Animal sinew or woven fiber rope coated in rubber, and then rolled in very hard crushed rock would make a rudimentary equivalent of what we now have as diamond saws. Not as good, but it would work to cut sandstone with a bit of work.
Anyone that's ever seen a good bricklayer at work would have seen them scoring the four sides of a brick with a trowel, then give it a good wallop with the trowel, and the brick would split with fairly even faces on both bits of the brick. The same will happen for sandstone of much larger size, and the ancients could have used hydraulics to their advantage here as well.
It's been proven that clay can be used as "lubrication". Take a block of stone from a quarry and drag it along quite a distance on a sort of flat cobbled road covered in clay to lubricate/ease things, and at the end of the trip, the random roughness of the cobbled road will have produced a fairly flat surface on the stone. Drag hundreds of stones along like this, and the "road" will have been worn smooth, and as a result produce even flatter and smoother stones.
So what happened to my hypothetical road ? - well don't use it for a couple of hundred years, and new growth in a rain forest will obliterate it completely, pushing all the rocks that made it out of the way. Add some regular water running over the rocks, and the smooth faces will disappear, leaving nothing for us to find.

OK, enough speculation, lest I completely ruin my miniscule reputation or bore someone to death :big:

Kind regards, Arnold

 

[mklotz]

Some other things to think about...

We have no idea what knowledge of chemistry the ancients had. They must have been aware of the effect of even mild acids on limestone. What other chemical concoctions had they discovered?

Animal-powered millstones used by many societies grind themselves flat rather quickly. You don't have to be terribly inventive to visualize extending that process to large construction blocks fitted with suitable temporary wooden pivots.

As the Egyptians discovered, it's far easier to float heavy stone monoliths than it is to drag them. Stonehenge is conveniently close to the Avon river. The Mayans were accomplished hydrologists. Any transport canals they might have dug would have succumbed to the jungle long ago. The ancient Greeks moved monoliths by securely attaching wooden quarter circles to the stone and rolling them to the desired location.

IIRC, the wooden piston for the Newcomen atmospheric engine was sized by using a team of horses to drag it back and forth in a shallow groove in the earth lined with sand. That was early 1700s. We're not that far removed from our ancestors' machining methods. We still drill neat circular holes in glass by rotating a brass pipe in a slurry of carborundum powder.

 

[joshagrady]

The Roman gold mines at Las Médulas in northwestern Spain (Wikipedia Link) are an impressive testament to the ancient understanding of hydraulic force. As a side note, according to information in the visitor's center (for what that's worth), signs of atmospheric contamination from the smelting operation on site are observable in tree ring samples from the era, throughout western Europe.

Mistakes will have been ritually destroyed or recycled. We see only the end product, not the sequence of mistakes that led to it.

Well, I've finally found a justification for my shop. I'm leaving a catalog of errors so that future anthropologists don't fall into the same error of believing that we were all "superhuman" technologists.

 

[mklotz]

Returning to the original question...

The three plate method, applied properly, will indeed generate three flat plates. However, one must religiously observe the plate rotation regimen while grinding the plates. There are non-flat surfaces such that three will fit together in all possible permutations. The hyperbolic paraboloid is the most obvious example.

 

[krv3000]

HI just my bit any one remember when they where apprentices and the tools they had to mack in my case a center finder tap handles 6" and 12" hacksaw frames 6" and 12" st rate edge and so on all where checked on standards which where checked and calibrated every 12 months by whats and meshers in the UK and they set their flat plate test on witworhts flat plate if memory serves me right every 5 years all the governments whats and mesher ments are checked i have seen sum of the tooling used to do this and non of them are moden