What can I make to keep track of time without electricity

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sophiecentaur said:
Why not go back and ask 'them' to set realistic targets for this project or call their bluff and ask how 'they' would do it.
Agreed. I'll be more direct: Michael, what is the purpose of this project? Why are you undertaking it? Knowing that might help people understand your constraints and be able to provide more/better assistance.
 
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I just want to make something like a stopwatch that can accurately measure time within a certain interval of time
 
Michael2525 said:
I just want to make something like a stopwatch that can accurately measure time within a certain interval of time
Thanks. "Certain interval"? Is your "accuracy" constraint based on something or just randomly selected? And do you need precision or accuracy or both?
 
russ_watters said:
Thanks. "Certain interval"? Is your "accuracy" constraint based on something or just randomly selected? And do you need precision or accuracy or both?
What is the difference between accuracy and precision? I just need something that can tell the duration of time like a stopwatch does. It doesn't need to last hours, just a few minutes.
 
Michael2525 said:
What is the difference between accuracy and precision? I just need something that can tell the duration of time like a stopwatch does. It doesn't need to last hours, just a few minutes.
Accuracy-and-precision-picture.png

Given that it doesn't need to last very long, that means it doesn't need to be very accurate only very precise.

Are there any other constraints we should know about? Also, the reason I asked where the constraints came from is that if we determine you can't have the precision you desire, you may decide to still do the project with less precision or not. If the constraints are not that important, you might get more people to help you who would otherwise avoid what they think is an impossible project. Also, explaining the purpose might convince people to help you who might otherwise consider this a pointless project.
 
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Michael2525 said:
What is the difference between accuracy and precision?

Google knows these kinds of things.

Michael2525 said:
I just need something that can tell the duration of time like a stopwatch does.

Why not simply buy a http://www.bodytronics.com/p/two.html?gclid=CKba6NLDxsoCFRCNaQodw5UPPw?
 
russ_watters said:
Accuracy-and-precision-picture.png

Given that it doesn't need to last very long, that means it doesn't need to be very accurate only very precise.

Are there any other constraints we should know about?
Thanks for the pic.
Other than it cannot use electricity there isn't much constraints. Of coarse it has to be something I can make. (Preferably something out of wood or something I can buy at a local department store.)
 
Michael2525 said:
Other than it cannot use electricity there isn't much constraints. Of coarse it has to be something I can make. (Preferably something out of wood or something I can buy at a local department store.)
Please see my additional questions I added after you responded. It would be helpful if you answered them. You might get more/more useful responses if we understood the point of this better.
 
russ_watters said:
Please see my additional questions I added after you responded. It would be helpful if you answered them. You might get more/more useful responses if we understood the point of this better.
So basically what I am trying to build is a device that can precisely measure a duration (perhaps 95 seconds) like a stopwatch.
 
Michael2525 said:
So basically what I am trying to build is a device that can precisely measure a duration (perhaps 95 seconds) like a stopwatch.
We know what. I asked why: why are you undertaking this? Why do you have these constraints (where did they come from?)?
 
It's just a challenge I wanted to undertake, and I like building stuff.
 
Great! In that case, all of the constraints are negotiable, which means people don't have to follow them if they think they are unrealistic. So you'll have better odds of making something that works instead of not being able to make anything at all.
 
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Michael2525 said:
Would this work?

The rolling ball and the collisions at each end of the track would involve significant loss of energy. Throw away the ball and the pendulum will go for much longer and with a better defined oscillation period.
 
Michael2525 said:
It's just a challenge I wanted to undertake, and I like building stuff.
If you were to read around about ancient timekeeping methods then you could go back far enough and find something appropriate to build. It will demonstrate to you just how useful Electricity can be because an electrical solution is much more achievable for the hobbyist than regular clock making. An electromagnetic / optical system for maintaining a well made pendulum would give you a good chance of achieving your original spec. Your advantage is that this thing doesn't have to work on a small ship, rolling about in an Atlantic gale!
 
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Michael2525 said:
It's just a challenge I wanted to undertake, and I like building stuff.

It is time for you to stop being so mysterious. If you want our help, tell about your project and the origin of these constraints.