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Author Topic: stepper driven mechanical clock with RTC  (Read 869 times)
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I looking at the feasibility into designing a mechanical clock driven by a stepper motor with no escapement as I'm after a true sweeping second hand. I would like to be able to correct the time with something like this - Ultra-precise Real Time Clock - v2.1 ( http://www.adafruit.com/products/255 ). I'm wondering what would be the best way to get feedback from the clock works to tell the arduino the time on the works.

Regards

Dale


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The last thing you did is where you should start looking.
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Light beam or Hall effect sensor
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The way you have it in your schematic isn't the same as how you have it wired up!

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Hi, So this would be a clock with gears for the second-minute-hour relationship and one stepper motor driving second hand??

You might use 3 reflective IR sensors like these: http://goo.gl/05jZ9

If you have the conventional coaxial connection to the 3 hands, you could selectively make them reflective at different distances from the center, have 3 sensors, and be able to detect the 12:00:00 condition.  Drive to that and then assume your stepper won't miss steps to set the time.

At least it would be impressive while setting the time. Kind of like a cheap movie: "Time Passes"....


DISCLAIMER: Mentioned stuff from my own shop...
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Regards, Terry King terry@yourduino.com  - Check great prices, devices and Arduino-related boards at http://YourDuino.com
HOW-TO: http://ArduinoInfo.Info

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Hi,

Thanks for the replies, yes it will be driven off one stepper, I might even add an idler gear off the main hour hand gear to detect position. Terry I had a look on your site, I do like the look of the light beam sensor, all I would need to do is mill a slot in the idler gear.

Regards

Dale
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Topsham, Vermont USA
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Dale, if you can get access to the gears "back there" for a transmissive beam you could, use something like this:

http://goo.gl/eBpHx

or pairs of these (first 2 items here: http://goo.gl/SuCwq)

You'd only need a small hole in the gear.


DISCLAIMER: Mentioned stuff from my own shop...
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Regards, Terry King terry@yourduino.com  - Check great prices, devices and Arduino-related boards at http://YourDuino.com
HOW-TO: http://ArduinoInfo.Info

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Hi,

Yes I think this is the route I'll take ( transmissive beam ), still in the design stage so I need to finalize my designs

Many thanks

Dale
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