Cable for a 31 day clock

Discussion in 'Clock Construction' started by doc_fields, Dec 18, 2018.

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  1. doc_fields

    doc_fields Registered User

    Sep 29, 2004
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    I've been thinking about building some 31 day clocks to be sold to some of my Amish friends and others also. What I am wondering is this: why couldn't a small diameter cable (such as used on modern GF clocks) be wound on a small diameter shaft, and when wound full on that shaft, let it double back over itself, 2 or 3 times to help get a 31 day run out of it? Kind of like how fishing line used to wind on the old time spools with a wire guide assisting it to evenly wind onto it. I've gotten a hint sometimes that this is frowned upon, but just wondering why. Thanks for your help!.............................gary
     
  2. David S

    David S Registered User
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    Dec 18, 2011
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    Since you specify a small diameter shaft, this means that you will have to use a fairly heavy weight to get the required torque. This could lead to coil binding if the cable gets stuck between the adjacent wraps.

    At least this would be my concern.

    David
     
  3. Phil Burman

    Phil Burman Registered User

    Mar 8, 2014
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    This will change the effective diameter of the drum and therefore the applied torque, which in turn will change the amplitude and the clock rate.

    Phil

    PS: plus lots of added friction.
     
  4. doc_fields

    doc_fields Registered User

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    Thanks Dave and Phil for your replies, I will consider something else then!............................gary
     
  5. David S

    David S Registered User
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    Gary these are just opinions. I wouldn't be too hard for you to try and experiment and see how it goes.

    David
     
  6. steve323

    steve323 Registered User

    Sep 25, 2018
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    I built a clock with 8' of fishing line wrapped around a 1" drum. The line wraps randomly and overlaps itself to around 1.1" diameter. This increases the driving force about 10% at some times but not others. The suggestion about extra friction from the overlapping layers is probably also occurring.

    The other effect is that the line often makes a pinging sound as the overlapping layers unwind from each other. The frequency changes depending on the distance to the weight.

    A more predictable result could be created by using a traditional winding drum and adding an additional gear to the train.

    Steve
     
  7. doc_fields

    doc_fields Registered User

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    No bother David!

    Of course, some of the idea I had was to use Butter Bearings part way in the train up to the minute arbor, with the rest using jewels to the escape wheel and verge. My Amish friends like 31 Day clocks, and I do too. Just something to try and "putz" with! ;)................................gary
     
  8. David S

    David S Registered User
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    Gary,
    Forget the butter bearings and jewels. I am still awaiting your experience with IGUS engineered polymeric bearings. :)

    David
     
  9. doc_fields

    doc_fields Registered User

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    David;

    I really don't have a lot to report on the polymeric bearings,..............yet. The clock I made these for didn't really run for long, as my customer felt there was an issue with time accuracy. As this was completed and sent to him, what, 1 1/2-2 years ago, we discussed the issue, and I awaited it's return to me. I just received it around October this year. So far, it was a very minor adjustment to the "+" side. It's undergoing a second timing test with another clock that I completed, with the butter bearings bearings and a few jewels.

    The particular polymeric stock I used was 10 mm. in diameter. I had to reduce it down to 1.80 mm. to install it in the reamed holes as I would a regular bushing. LOTS of swarf obviously, but another annoying problem of what I call "skirting", where some of the material in being cut was rolling back over the stock rather than parting off, like a skirt rolling up the legs. I tried making sure my cutting tool was sharp, with a lesser deep cut, but it still rolled up. It was a little discouraging trying to turn a specific diameter for the bush.

    As a pressed in bushing, I sometimes had to use superglue to hold it in place, even being a little oversized by 1-2 mm. Also, as the clock plates were thin, the bushing I made for the minute arbor wheel in the back plate was one I had to superglue, as there was no way to put a flange either on the outside of the plate, nor the inside to give it a little more surface contact to keep it in place.

    As far as long term use or effectiveness in its use as a clock bushing, only time will tell. I haven't had enough time to evaluate that.

    As far as their usefulness, it would be nice to see them actually make some bushings out of this material for clock work. If any of you have experience with hay balers, bearings don't seem to last long in them, yet they are making polymeric bearings for use in them, and seem to do as well or better than the ball bearing ones.

    Hope this helps a little!...........................gary
     

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