Large wheels vs more wheels

Discussion in 'Clock Construction' started by dandydude, Mar 9, 2016.

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  1. dandydude

    dandydude Registered User

    Nov 30, 2014
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    This is regarding the going train. Which system is more efficient in terms of power required to run a clock.

    Option 1
    Really large wheels but lesser number of wheels

    Option 2
    smaller wheels but more number of wheels. Each wheel contributes to a small gear ratio in this case.

    Is the weight required to run directly proportional to the gear ratio?

  2. jhe.1973

    jhe.1973 Registered User
    NAWCC Business

    Feb 12, 2011
    Arizona, USA
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    Hello Dandy,

    I haven't been here for awhile and I noticed this thread has no responses so I'll toss out some considerations. I am wondering the same thing as you and I have been kicking this question around for awhile.

    It seems to me that reducing the number of arbors is a good thing up to a point.

    Obviously, eliminating arbors eliminates the friction that each set of pivots introduces. The possibility of uneven transmission of motion from arbor to arbor is also eliminated as arbors are eliminated.

    It seems to me that one problem that might arise with large wheels and fewer of them, is that the larger wheels will have a greater flywheel effect and require more energy to start moving with each beat.

    To illustrate this thought, if a person had just one great wheel driving the verge directly, it might require a surprising amount of weight to start it moving. Next, because it would have greater mass to to keep it rotating, it might strike the pallets with a higher shock then would be desired for accurate timekeeping.

    It seems to me that the required weight is less affected by the gear ratio then it is by the total friction of whatever system one is considering.

    I think great wheel clocks are really cool looking and the concept is one that I would like to explore. It likely will have to wait for my ideal world of being closed up in my finished shop with enough food and water (and funds) to explore all the ideas I have.

    Until then, I am still playing around with the idea of large wheels.

  3. tok-tokkie

    tok-tokkie Registered User

    Nov 25, 2010
    Cape Town, South Africa
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    #3 tok-tokkie, May 13, 2016
    Last edited: May 13, 2016
    Here is a clock that uses 660 tooth wheel with 11 tooth pinion for 60:1. It also has a 400 tooth wheel. But when doing the min/sec with just one gearset the one arbor goes anti-clock. To deal with that you use a wheel with the minute numbers on it so the numbers pass through a window. It disguises the fact that it is turning the wrong way.

    By the way this is the most efficient clock I have come across - it runs on just 4 uW (micro Watts). A typical longcase clock with Graham dead beat escape runs on about 65 uW.

    Other clock on this site including a 4 year running clock.
  4. Tinker Dwight

    Tinker Dwight Registered User

    Oct 11, 2010
    Calif. USA
    I vote for larger pinions.
    Tinker Dwight

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