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mechanical accuracy
How can one make simple geometrical solids like cuboid and cylinder with 0.1mm geometrical error using naturally available and abundant materials only ( like sand, clay, soil, stone, iron, wood, animal parts, other bio parts and water) ? you are not allowed to use any man made tool or object, only natural materials.
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No this is not a homework. This is my personal question, how can something like this be a homework question. I'm last year student in university, mechanical engineering department.
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[QUOTE=roboticmehdi;7422]/...how can something like this be a homework question.[/QUOTE]
Because this question, almost word for word, has been asked here before.
[QUOTE=roboticmehdi;7422]I'm last year student in university, mechanical engineering department.[/QUOTE]
Substitute "homework" for "project work" then. Same dog, different collar.
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[QUOTE=roboticmehdi;7422]No this is not a homework. This is my personal question, how can something like this be a homework question. I'm last year student in university, mechanical engineering department.[/QUOTE]
Ok, so why would you want to build
[quote]geometrical solids like cuboid and cylinder with 0.1mm geometrical error using naturally available and abundant materials only[/quote]
Why avoid modern tools?
0.1 mm is less than .004"...
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If its not homework, what possible value could the question have in the real world? Even if you were able to construct some geometrically perfect structure using only those materials, you would have no way of verifying it because you could not measure it. So, what's the purpose? Just idle personal curiosity?
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[QUOTE=Cake of Doom;7423]Because this question, almost word for word, has been asked here before.
Substitute "homework" for "project work" then. Same dog, different collar.[/QUOTE]
Really ? Can you give the link please ?
They don't give projects like this, it's my personal question.
[QUOTE=Kelly Bramble;7424]Ok, so why would you want to build
Why avoid modern tools?
0.1 mm is less than .004"...[/QUOTE]
Because I want to do so.
[QUOTE=jboggs;7425]If its not homework, what possible value could the question have in the real world? Even if you were able to construct some geometrically perfect structure using only those materials, you would have no way of verifying it because you could not measure it. So, what's the purpose? Just idle personal curiosity?[/QUOTE]
Oh, for the last time, THIS IS NOT A HOME-WORK or project or anything else assigned to me by somebody. It is my personal question. I want to know this because people in the pasr must have done so, and thanks to them we take machine tools for granted and don't even remember their effort. yes it is personal curiosity but actually more than that. I just really want to know this.
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First time this question came to mind about a year ago and I still can't answer it !
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Hey, yes you are right this question has been asked here before, i found it, it was asked by user: roboticmehdi, who is ME !!! I asked this question but it seems I have forgotten about it. See ? this is not a homework or project.
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But still the answers were not satisfying, it seems nobody can answer this question.
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[QUOTE=roboticmehdi;7429]But still the answers were not satisfying, it seems nobody can answer this question.[/QUOTE]
Ok, do you want to control form, size, distance, location, repeatability...
Again - why no tools method?
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[QUOTE=Kelly Bramble;7430]Ok, do you want to control form, size, distance, location, repeatability...
Again - why no tools method?[/QUOTE]
Using tools is easy, I want to do it hard way and primitive way but still acquire error of no more than 0.1mm which, in my opinion, is the highest acceptable error. If know how to do it, I will do it for sure and I will never forget the methods in my life.
I want to make primitive and simple geometrical solids, especially cuboid and cylinder, out of and using only abundant natural materials like: sand, clay, soil, stone, iron, water, wood, animal parts and other bio-materials available naturally. I can tell dimensions by picking up fibers and cutting them to lengths that I want. What do you mean by: "[COLOR=#333333]Ok, do you want to control form, size, distance, location, repeatability...[/COLOR] "
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OK, it sounds like you just have a natural curiosity on how our ancestors developed the tools and methods allowing the construction of precise machinery and components. Your question, and your arbitrary standard of 0.1mm, requires a jump of several centuries of technical development from the days when an inch was defined as the "length of the king's thumb". I would suggest you read a few books on the history of technology. If you can find it on DVD, there was an amazing series on PBS MANY years ago called "Connections". It was absolutely fascinating. It was purely personal stories that showed the string of accidents and discoveries that led from the development of the plow in pre-historic Egypt to the digital computer, or how the invention of stirrups (to be added to saddles) led to some other amazing modern convenience. I would highly recommend the NOVA series called "Lost at Sea: The Search for Longitude", or the book on which it is based, or the movie "Longitude" to learn about how the invention of a device to precisely measure elapsed time allowed an explosion in worldwide commerce. You will also learn a lot about how the builder of that device actually did it. There are many books on the advancement of technology and measurement of distance, time, force, and other variables. I'm sure they would satisfy some of your curiosity.
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roboticmehdi, man throughout even earliest prehistory is first by definition a tool maker. Any appropriately naturally shaped rock, animal bone or wooden stick is potentially a tool. I think you are confusing "man made tools" with modern techniques and materials. Any of the shapes you describe could themselves be or represent a man made tool. There are many examples of items made, both simple and complex of many natural materials by cutting or abrading using other shapes of harder natural minerals, softer materials combine with abrasives such as sand or volcanic pumice or being drilled using shaped drills made from animal bone. Also, items such as unfired bricks can be made of clay or soil using wooden forms. At the same time, you should be aware that what you might consider that tools and weapons made from iron, what you might consider a technologically advanced material, were made from meteorites and heated in what we would consider sophisticated kilnes constructed utilizing a combination of carefully selected clays from varied locations by a group of very early African tribes and shaped using stone "tools". Generally, within the accuracy you selected, the advances we have achieved are not so much the ability to make the items but the ability to make them faster and with more repeatability. I would also ask you how you would intend to make your measuring tool without using a modern tool. The accuracy of an item is defined by its application, not some arbitrarily selected value. Measurement is principally used to fit an item to a mating item or for repeatability in making additional similar items.
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[QUOTE=jboggs;7436]OK, it sounds like you just have a natural curiosity on how our ancestors developed the tools and methods allowing the construction of precise machinery and components. Your question, and your arbitrary standard of 0.1mm, requires a jump of several centuries of technical development from the days when an inch was defined as the "length of the king's thumb". I would suggest you read a few books on the history of technology. If you can find it on DVD, there was an amazing series on PBS MANY years ago called "Connections". It was absolutely fascinating. It was purely personal stories that showed the string of accidents and discoveries that led from the development of the plow in pre-historic Egypt to the digital computer, or how the invention of stirrups (to be added to saddles) led to some other amazing modern convenience. I would highly recommend the NOVA series called "Lost at Sea: The Search for Longitude", or the book on which it is based, or the movie "Longitude" to learn about how the invention of a device to precisely measure elapsed time allowed an explosion in worldwide commerce. You will also learn a lot about how the builder of that device actually did it. There are many books on the advancement of technology and measurement of distance, time, force, and other variables. I'm sure they would satisfy some of your curiosity.[/QUOTE]
Thanks! I will try to find things you suggested.
[QUOTE=JAlberts;7439]roboticmehdi, man throughout even earliest prehistory is first by definition a tool maker. Any appropriately naturally shaped rock, animal bone or wooden stick is potentially a tool. I think you are confusing "man made tools" with modern techniques and materials. Any of the shapes you describe could themselves be or represent a man made tool. There are many examples of items made, both simple and complex of many natural materials by cutting or abrading using other shapes of harder natural minerals, softer materials combine with abrasives such as sand or volcanic pumice or being drilled using shaped drills made from animal bone. Also, items such as unfired bricks can be made of clay or soil using wooden forms. At the same time, you should be aware that what you might consider that tools and weapons made from iron, what you might consider a technologically advanced material, were made from meteorites and heated in what we would consider sophisticated kilnes constructed utilizing a combination of carefully selected clays from varied locations by a group of very early African tribes and shaped using stone "tools". Generally, within the accuracy you selected, the advances we have achieved are not so much the ability to make the items but the ability to make them faster and with more repeatability. I would also ask you how you would intend to make your measuring tool without using a modern tool. The accuracy of an item is defined by its application, not some arbitrarily selected value. Measurement is principally used to fit an item to a mating item or for repeatability in making additional similar items.[/QUOTE] Measuring tool is simply a piece of fiber cut to a certain length. Of course rock and bone are tools, thats what i said, pff.. How can cuboid and cylinder be tools if you havent made them yet ?
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Can we talk on skype about this ? Please add me if you wish to discuss this : mehdi.mehdizade
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"Measuring tool is simply a piece of fiber cut to a certain length."
You are already outside your 0.1mm tolerance.
It will stretch more than that.
And you can't visually distinguish that small a distance.
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[QUOTE=jboggs;7442]"Measuring tool is simply a piece of fiber cut to a certain length."
You are already outside your 0.1mm tolerance.
It will stretch more than that.
And you can't visually distinguish that small a distance.[/QUOTE]
There's the rub... In sheet metal, weldments, etc... measuring and fabrication in often done to tape measure increments. I think one could be repeatable and measurable to .125' - .250" using natural methods..
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[QUOTE=jboggs;7442]"Measuring tool is simply a piece of fiber cut to a certain length."
You are already outside your 0.1mm tolerance.
It will stretch more than that.
And you can't visually distinguish that small a distance.[/QUOTE]
I am not trying to make a precise length fiber, here I am defining my length unit by getting some fiber length and calling it for example: mhd. then i try to make a solid cuboid and cylinder and give related dimensions according to hits new unit. for example i want a cuboid 3x5x7 mhds.
[QUOTE=Kelly Bramble;7443]There's the rub... In sheet metal, weldments, etc... measuring and fabrication in often done to tape measure increments. I think one could be repeatable and measurable to .125' - .250" using natural methods..[/QUOTE]
correct !
I notice that people don't quite understand what i really want to do.
add me on skype please and we'll talk about it :D don't afraid i don't bite through skype :D
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I am sure I can explain myself better while actually talking to you guys. just add me and we'll arrange the call according to ours country times. im am from Azerbaijan but I live in Turkey. my skype name is: mehdi.mehdizade It's night here time to sleep, so good night everybody. see ya tomorrow :)
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[QUOTE=roboticmehdi;7445]I am sure I can explain myself better while actually talking to you guys. just add me and we'll arrange the call according to ours country times. im am from Azerbaijan but I live in Turkey. my skype name is: mehdi.mehdizade It's night here time to sleep, so good night everybody. see ya tomorrow :)[/QUOTE]
If you can't define it in writing then you don't know what you want...
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If you want a good idea of how the ancients worked things out, you could do a lot worse than look at De Architectura Libri Decem. It's a book on Roman surveying and architectural practices circa. 20 BC.
As the title suggests, it's ten books so you may need quite a bit of free time.
Good luck.
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[QUOTE=Kelly Bramble;7446]If you can't define it in writing then you don't know what you want...[/QUOTE]
I know what I want exactly and I explain it, but first you tell this is homework then you tell why not use modern tool then you say how you will measure without a centimeter/inch scale. You dont or dont want to understand me because this is tough question for you and for me. no question is bad.
[QUOTE=Cake of Doom;7450]If you want a good idea of how the ancients worked things out, you could do a lot worse than look at De Architectura Libri Decem. It's a book on Roman surveying and architectural practices circa. 20 BC.
As the title suggests, it's ten books so you may need quite a bit of free time.
Good luck.[/QUOTE]
I already have a look at that book, no such information can be found in that book. that book is mostly about the design of structures.
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I think the trouble you are going to get with this, is that by the time humans were making cones and cubes and cylinders and whatnot; units and systems of measurements were already in place giving an early form to national standardisation. The Greeks had a way of doing things, the Egyptians had a way and so on and so forth. Prior to to the building of complex structures and mechanisms, I'd imagine that everything was as big as needed to be based on the judgement of whomever was building it.
If I was a teacher, this would be a purely practical lesson based on trail and error. Get some rudimentary items, sit in the garden and give it a go.
Good luck.
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[QUOTE=Cake of Doom;7453]I think the trouble you are going to get with this, is that by the time humans were making cones and cubes and cylinders and whatnot; units and systems of measurements were already in place giving an early form to national standardisation. The Greeks had a way of doing things, the Egyptians had a way and so on and so forth. Prior to to the building of complex structures and mechanisms, I'd imagine that everything was as big as needed to be based on the judgement of whomever was building it.
If I was a teacher, this would be a purely practical lesson based on trail and error. Get some rudimentary items, sit in the garden and give it a go.
Good luck.[/QUOTE]
But like I said my question is not about standards, that is very easy. The only unit I need for making solid object is length to tell the dimensions on cuboid or cylinder for example. And that unit as I said could be some length of fiber that I call mhd. then I tell all friends that when talking about dimensions let's talk in terms of mhds so we can understand each other.
Actually I am thinking of going to garden and try to do what I can the problem is I don't enev know where to start. Say I have some stones around. I chip them by striking against each other and make descent kinda of knife tool( which won't be dimensionally very accurate but approximation to a knife, say with error of 2 mm). Then using this tool and my mhd scale fiber I want to make cuboid 3x5x7mhds and cylinder 5(diameter)x14(length)mhds, say my 1 mhd is close to about 1 cm( so you can have idea on how big these objects are). So, try and you fail to achieve an acceptable accuracy.
Months ago I tried to cut a cylinder out of wax using ordinary knife and it's accuracy was not acceptable. was something like 3 mm perhaps. So doing these things by hand you can't really get good acccuracy. You may say how come sculptors do good sculptures, well sculptures are not geometrical objects they are like somebody's face or body, I mean not straight stuff but curvy and irregular stuff. There must be practical methods to obtain good acceptable accuracy and ensure it. I am looking for them. Today accurate tool creates other tools and that tool creates other tool. But in early days there accurate tool around. so they must have somehow started all this.
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It sounds like you're trying to solve a problem that has already been solved. I'm pretty sure that early man didn't care about tolerances when he was napping a piece of flint for a knife or spear head. He also wouldn't have bothered himself with how to carve out a dimensionally accurate cone.
Looking to recreate todays accuracy using bygone methods is always going to cause you problems. Trying to eye in 0.1 mm is ridiculous.
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[QUOTE=Cake of Doom;7455]It sounds like you're trying to solve a problem that has already been solved. I'm pretty sure that early man didn't care about tolerances when he was napping a piece of flint for a knife or spear head. He also wouldn't have bothered himself with how to carve out a dimensionally accurate cone.
Looking to recreate todays accuracy using bygone methods is always going to cause you problems. Trying to eye in 0.1 mm is ridiculous.[/QUOTE]
But when they started to care, how did they do stuff? thats what I am asking.
early man- no accuracy
todays man- very high accuracy, sometimes even to scale of atoms !! they make sphere balls with an error of a few atoms !!
What I am asking is, how that transition exactly happened. I know it took some time etc, but how exactly. what specificly they did.
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for example: what steps it takes from no accuracy at all to an accuracy with the error of no more than about 0.1mm, this is a huge number compared to sizes of atoms that todays highest precision can do.
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You have already answered your own question in a previous post: we invented better tools and developed better techniques. Each time improving on the last until we get all the way to Joseph Whitworth and Henry Maudsley and anal levels of precision. Imagine what they would do with todays methods and technology.
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[QUOTE=Cake of Doom;7458]You have already answered your own question in a previous post: we invented better tools and developed better techniques. Each time improving on the last until we get all the way to Joseph Whitworth and Henry Maudsley and anal levels of precision. Imagine what they would do with todays methods and technology.[/QUOTE]
oh again you are giving just general answer. of course everybody knows we developed better tools using existing tools. but how exactly, i need more specific answer like the procedure how to do it. what are steps from no accuracy at all to about 0.1mm accuracy. if you don't know the answer then say that you don't know, you are trying to show that you the answer by bringing a very general answer and bypassing the details. :bash:
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If I leave you on the island, give you a cm scale only and tell you : "either make an acceptably accurate and precise 3x5x7 cuboid and a 5x14 cylinder in five days or you'll stay here forever" , would you be able to do it ? No. because you don't know how !
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Nobody was measuring stuff just to be measuring stuff. They had to have a reason. As those reasons changed so did the measurement methods. As in most things, you can follow the money. In my opinion, the main driving force behind the development of high precision measuring methods was in the growth of mass production techniques. For example, man knew how to make guns for centuries before anyone ever thought about making all the parts EXACTLY alike so they could be interchangeable, thus enabling the mass production of guns . . . and the resulting profit. Follow the money. The same story occurs in numerous other fields ranging from farm implements to warships. To learn about the "how", look at the "why".
Man didn't jump from measuring the speed of a ship speed by literally counting the "knots" in a trailing rope to using lasers and GPS overnight. All the developments in that field, like so many others, were so gradual and slow that the individuals involved barely even noticed the difference. Comparing the methods of today to those of decades or centuries ago requires an understanding of that evolutionary process.
Honestly, I still have no idea why you seem so captivated by the challenge to try to recreate something that was never done in the first place, and I am rapidly losing interest.
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[QUOTE=roboticmehdi;7460]If I leave you on the island, give you a cm scale only and tell you : "either make an acceptably accurate and precise 3x5x7 cuboid and a 5x14 cylinder in five days or you'll stay here forever" , would you be able to do it ? No. because you don't know how ![/QUOTE]
What? I think I would be more interested on that island in making a spear, collecting water, food and finding/building shelter and none of these will require accuracy of 0.1 mm. I have no idea why I would be stuck if I could not build a cuboid..
Perhaps I should also build a low mechanical tolerance club to defend myself against my captor..
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[QUOTE=jboggs;7461]Nobody was measuring stuff just to be measuring stuff. They had to have a reason. As those reasons changed so did the measurement methods. As in most things, you can follow the money. In my opinion, the main driving force behind the development of high precision measuring methods was in the growth of mass production techniques. For example, man knew how to make guns for centuries before anyone ever thought about making all the parts EXACTLY alike so they could be interchangeable, thus enabling the mass production of guns . . . and the resulting profit. Follow the money. The same story occurs in numerous other fields ranging from farm implements to warships. To learn about the "how", look at the "why".
Man didn't jump from measuring the speed of a ship speed by literally counting the "knots" in a trailing rope to using lasers and GPS overnight. All the developments in that field, like so many others, were so gradual and slow that the individuals involved barely even noticed the difference. Comparing the methods of today to those of decades or centuries ago requires an understanding of that evolutionary process.
Honestly, I still have no idea why you seem so captivated by the challenge to try to recreate something that was never done in the first place, and I am rapidly losing interest.[/QUOTE]
:banghead:
[QUOTE=Kelly Bramble;7462]What? I think I would be more interested on that island in making a spear, collecting water, food and finding/building shelter and none of these will require accuracy of 0.1 mm. I have no idea why I would be stuck if I could not build a cuboid..
Perhaps I should also build a low mechanical tolerance club to defend myself against my captor..[/QUOTE]
:banghead:
.....
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If you examine manufacturing methods used by American pioneers in build log cabins, you will find they used clay/mud to seal the gaps in the wall logs. This is because building a tight tolerance fitting logs was not a reasonable or achievable task.
Even today with all of our modern and high accuracy tools one should not specify mechanical tolerances greater than what is needed.
As far as manufacturing your 5 x 14 cylinder I would find a sharp rock make an ax, cut down a tree and core out the log. Accuracy not required..... it just needs to work.
If bamboo is available, cut as required and poof! done.
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You simply don't know the answer. Ok.
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It probably went something like: This stone is rubbish for bashing things and it hurts my hand! I wonder what happens when I tie it to the end of a stick...
[quote=roboticmehdi]oh again you are giving just general answer. of course everybody knows we developed better tools using existing tools. but how exactly, i need more specific answer like the procedure how to do it. what are steps from no accuracy at all to about 0.1mm accuracy. if you don't know the answer then say that you don't know, you are trying to show that you the answer by bringing a very general answer and bypassing the details.[/quote]
You're getting general answers because your question is basically "how did people outside of recorded history do things and why did they make it better?" which is a rubbish question.
[quote=roboticmehdi]If I leave you on the island, give you a cm scale only and tell you : "either make an acceptably accurate and precise 3x5x7 cuboid and a 5x14 cylinder in five days or you'll stay here forever" , would you be able to do it ? No. because you don't know how ![/quote]
"Acceptably accurate" is arbitrary. When working with hand tools and standard measuring devices +/-2.0 mm is deemed acceptable. Tolerances change depending on what's available to get the job done. Using rudimentary tools such as flint and bone, I'd be happy to be within +/-6.0 mm.
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[COLOR=#333333]You simply don't know the answer. Ok. I got it, Ok.[/COLOR]
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why I ask you, xxxxx in first place, my bad.
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[QUOTE=roboticmehdi;7467][COLOR=#333333]You simply don't know the answer. Ok. I got it, Ok.[/COLOR][/QUOTE]
One can build a rock cylinder by simply taking a large rock and tapping on it for days with smaller rocks to hollow it out. Also, one could find clay, build a fire and form a pipe from hand or around a small tree log, fire the clay and you have a pipe of some low accuracy.
[COLOR=#ff0000]Does this hollow rock or clay pipe need to be 0.1 mm accurate in terms of form and size? NO! The ancients built what they needed for fit or function, nothing more.[/COLOR]
Here's what you're missing - building 3x5x7 cuboid and a 5x14 cylinder to 0.1 mm without modern tools to is just silly and not required on an island or otherwise. Your question remains academic in nature.