# Thread: mechanical accuracy

1. ## 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.

2. 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.

3. Originally Posted by roboticmehdi
/...how can something like this be a homework question.
Because this question, almost word for word, has been asked here before.

Originally Posted by roboticmehdi
I'm last year student in university, mechanical engineering department.
Substitute "homework" for "project work" then. Same dog, different collar.

4. Originally Posted by roboticmehdi
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.
Ok, so why would you want to build

geometrical solids like cuboid and cylinder with 0.1mm geometrical error using naturally available and abundant materials only
Why avoid modern tools?

0.1 mm is less than .004"...

5. 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?

6. Originally Posted by Cake of Doom
Because this question, almost word for word, has been asked here before.

Substitute "homework" for "project work" then. Same dog, different collar.
Really ? Can you give the link please ?

They don't give projects like this, it's my personal question.

Originally Posted by Kelly Bramble
Ok, so why would you want to build

Why avoid modern tools?

0.1 mm is less than .004"...
Because I want to do so.

Originally Posted by jboggs
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?
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.

7. First time this question came to mind about a year ago and I still can't answer it !

8. 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.

9. But still the answers were not satisfying, it seems nobody can answer this question.

10. Originally Posted by roboticmehdi
But still the answers were not satisfying, it seems nobody can answer this question.
Ok, do you want to control form, size, distance, location, repeatability...

Again - why no tools method?

11. Originally Posted by Kelly Bramble
Ok, do you want to control form, size, distance, location, repeatability...

Again - why no tools method?
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: "Ok, do you want to control form, size, distance, location, repeatability... "

12. 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.

14. Originally Posted by jboggs
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.
Thanks! I will try to find things you suggested.

Originally Posted by JAlberts
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 ?

15. Can we talk on skype about this ? Please add me if you wish to discuss this : mehdi.mehdizade

16. "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.

17. Originally Posted by jboggs
"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.
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..

18. Originally Posted by jboggs
"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.
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.

Originally Posted by Kelly Bramble
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..
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 don't afraid i don't bite through skype

19. 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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