How much power do I need?

Discussion in '400-Day & Atmos' started by KurtinSA, Mar 25, 2020 at 10:18 AM.

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  1. KurtinSA

    KurtinSA Registered User
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    Working a Konrad Mauch. After cleaning and reassembly, I let the clock run for over 12 hours and the rotation and over swing climbed to good numbers - about 300 deg of rotation and at least 45 deg of over swing. I put on the motion works and hands and the clock promptly stopped in 10 minutes. I removed the intermediate wheel and the clock still stopped in a short period of time. Trying to figure out what is going on, I stripped the motion works and only put back on the following in order - flat washer, cannon pinion, the minute hand, and hand nut with wavy washer. I started the clock a little after 8am and found the clock stopped by 8:45am this morning.

    The clock ran, in my estimation, quite well with nothing on the center arbor. Since all I've done is add things to the center arbor, it suggests there's not enough power to raise the minute hand. Are the rotation numbers I mentioned not good enough to power the minute hand? That just seems crazy to me. What am I missing?

    Kurt
     
  2. Rod Schaffter

    Rod Schaffter Registered User

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    If you take the minute hand off does it run?
     
  3. KurtinSA

    KurtinSA Registered User
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    #3 KurtinSA, Mar 25, 2020 at 12:06 PM
    Last edited: Mar 25, 2020 at 12:12 PM
    Yes, I'm sure it would.* Having just the cannon pinion and the inside flat washer in place would just "ride along" as the center arbor turned.

    The setup for the motion works should be to have enough friction between it and the center arbor so that the arbor will turn the motion works as the clock runs. The friction has to be low enough to allow a finger to move the minute hand to set the time...there's essentially a clutch built in with the friction. In theory, as I understand, if the minute hand was "welded" to the cannon pinion, all things being equal a clock should still run...you just wouldn't be able to turn the minute hand to set the time. That's all I see going on...I tighten the hand nut enough to create the friction needed, but still being able to turn the minute hand...but yet this clock won't lift the minute hand.

    Kurt

    *In reality I guess I don't know. I've rigged it up without the minute hand, but the hand nut is tight on the cannon pinion. I'll see if it runs.
     
  4. shutterbug

    shutterbug Moderator
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    Be sure your minute hand is not pressed against the hour cannon. If it was running that well, just adding the motion works should not have affected it much.
     
  5. KurtinSA

    KurtinSA Registered User
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    sb -

    In the scenery I described, there was no hour pipe...just the washer, cannon pinion, minute hand wavy washer, and hand nut. So the minute couldn't be rasied.

    To report on my new test, a little over an hour ago, I removed the minute hand and found a spacer so that I could put the hand nut back on and tighten up. The clock has been running ever since. So, it appears that the weight of the minute hand is too much...but I just get it when the over swing was so stout.

    Kurt
     
  6. Wayne A

    Wayne A Registered User

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    With that much swing it does seem like it should work. I wonder if the hands are original to the clock? Some hands get heavy to the point they probably should have had a counter weight designed in them.

    Does the spacer you added weigh at least as much as the minute hand? Just thinking if the added weight on the shaft was creating a bind somewhere.
     
  7. KurtinSA

    KurtinSA Registered User
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    The clock in question was shown in this thread:

    Konrad Mauch Suspension Spring

    As far as I know, the hands looks original.

    I guess I spoke too soon...my little experiment didn't work. The clock stopped a bit ago. As you can see from the picture, it shows the stack up of parts on the center arbor. I'm really confused...this doesn't add significant mass to the center arbor to turn, yet the clock ran with good numbers for over 12 hours and no motion works.

    Kurt

    KMauchCntArbor.jpg
     
  8. Wayne A

    Wayne A Registered User

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    Little slop in the pivots could potentially allow the gear mesh to pinch or bind. Maybe some burs on those gears that would bind with a little side load on them.

    Those hands look original for sure. Have a Koma with ornate hands that are just heavy, it works well enough with them though. Every time I look at my Atmos I see another design feature, the hands have counter ballances.
     
  9. KurtinSA

    KurtinSA Registered User
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    OK, I've stopped banging my head against the wall...for now. I've continued to play with this using just the cannon pinion and no intermediate wheel. Earlier yesterday, I turned the clock 180 degrees on the bench with the back plate in front of me. Seems that the pendulum hangs a little better that way. The clock ran all day long with no minute hand...just the stack up on the center arbor with a spacer for the minute hand. Hmmm... Then later yesterday afternoon, I decided to put the minute hand on...no hour pipe, hand, or intermediate wheel...clock still facing away from me. Is still running with good numbers 300 deg of rotation and 45 deg of over swing. I'll next put the rest of the motion works on and see what happens.

    I guess this particular clock is sensitive to the state of level of the clock and how the fork interacts with the anchor pin. What do I know? :?|

    Kurt
     
  10. Wayne A

    Wayne A Registered User

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    From run testing without the anchor in place you get an idea how very sensitive to orientation these clocks are. Any orientation that tends to have the pivot step up section contact the plates greatly drops power. Just that increased side friction on most clocks is enough to stop them. For example when you turn the movement so that the face would be strait up they will stop every time, often just 45deg tilt will stop them.
     
  11. KurtinSA

    KurtinSA Registered User
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    That's a good point, Wayne. But I wonder about when the clock is under full power. These clocks weren't manufactured with a super high degree of exactness...certainly not like an Atmos as an example. So, under full power, the forces between wheels and pinions must be providing some forces along the direction of the arbor, thus pushing an arbor such that the end shake is gone. I wonder how much a slight tilt would over come that, or worse add to it. Sure I could see that the driving forces of the movement being added to by the gravity of a tilt, but seems like the gravity part would be much less than the forces due to spring power in the train.

    Kurt
     
  12. KurtinSA

    KurtinSA Registered User
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    Well, so much for that experiment. After completely assembling the motion works, I started the clock a little after 6:00pm last night. Found it stopped this morning at 7:45pm. So, it was able to raise the hands thru 6:45pm but ran out of steam an hour later. Previously, I did a check of the motion works...left the center arbor in and manually turned the arbor trying to feel for any tightness in the motion works...I felt none. So, I really don't know where the power is being sucked off.

    Kurt
     
  13. clksmyhobby

    clksmyhobby Registered User

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    Hi Kurt,
    Are you operating from a full wind-up, minimal or in between?
    When I check a running train after cleaning, I turn the mechanism up, down and around to see if the gears continue to run with minimum clicks on the main spring. If they slow or stop (this has happened, mostly with miniature movements), I add a click or two. If they still show signs of slowing or stopping, I take it apart and do it all again.
    One clock in particular, 1930s SuP I've had for 3 years, exhibits what you are describing after a couple of months in operation - apparent loss of power. Main spring was even changed. After taking the anchor out, I find the train sluggish - again!
    I clean, check and start again - most recently, yesterday after reading your post. This makes 6 times with longest run time at 4 months.
    This time I noticed under magnification what appeared to be deposits at the bottom of the pinion leaves of the center wheel. This wheel has the most end play in the train. Soaked it in acetone, scraped it with a sharp clean toothpick - seems clean and burr free. Also cleaned the meshing gear teeth.Then I checked all the others, finding nothing. Assembled and started with with 2 full turns on main spring - normal operation after 18 hours.
     
  14. Wayne A

    Wayne A Registered User

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    So little power on the motion works I suspect a problem would be very difficult to feel by hand. I've seen industrial equipment gears jam and hold fast against 20lb of torque but the parts in hand could not be made to jam. Suspected then it was partly about the speed/inertia of hand operating the gears compared to how slow they moved in service.
    Motion gears are so loosely centered any sharp edges can be a problem. If I can feel any sharp points on the gears corners I'll knock them off with 2000 wet dry and always check for burs under magnification. Had trouble with the inside bore of the cannon having gouges running lengthwise on a few clocks too.
     
  15. KurtinSA

    KurtinSA Registered User
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    #15 KurtinSA, Mar 27, 2020 at 1:48 PM
    Last edited: Mar 27, 2020 at 2:01 PM
    An update. This morning a changed the clock level a bit, making the suspension spring parallel to the back plate. Clock ran for a good 4 hours with no issues...good movement.

    That said, I relooked at a few things:
    - I inspected the motion works for any issues...didn't see anything that I felt was wrong, but did file a few burs off the edges of some teeth
    - I tweaked the beat just a bit
    - I noticed that the gap between the fork and the anchor was probably much more than a paper thickness...can lose power with that. I tightened up the spacing.
    - The exit drop is smaller than the entrance drop...could be an issue. This clock has the eccentric on the front plate, although the saddle bracket has some slop to it. I loosened the bracket and raised it as much as it would go...might have helped the drops a small amount.

    It's been running nearly two hours now, with full motion works and hands. Still quite strong, even while raising the hand past 0:45 right now. Rotation is probably 300 degrees and 45 degrees of over swing. If it will keep doing that, I'll be pleased.

    One thing that I think I need some remedial training is how to properly oil a main spring. I have my technique and guess it works...maybe. I think I've heard that when winding a main spring, there shouldn't be any jumps or noises, meaning that the coils are sticking together. Well, I tend to hear noises once in a while after servicing my springs. I can see that sticking main springs will reduce power and even stop a clock prematurely.

    Thanks for the ideas...Kurt
     
  16. Wayne A

    Wayne A Registered User

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    Good deal. My favorite fix method, many small changes at the same time. :) Always called that shotgunning.
     
  17. KurtinSA

    KurtinSA Registered User
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    Yeah, I hate doing so many things at once. I think the fork clearance is more significance than the others. I don't know about others, but I'm not convinced something is going to work until it will run for at least 12 hours. But since I have only one spot to work on clocks, it kind of limits how I work on things. Bums me out having to wait so long between changes. I sooo want to move on to something else!

    Kurt
     
  18. clksmyhobby

    clksmyhobby Registered User

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    Good for you, Kurt. Still curious about how much the clock is wound while you are checking it.
    With problem clocks, I use the small change and check method too. Takes time, but since my work area is my garage in central Florida (no cooling system) I get breaks to cool off.
    My SuP stopped after 20+ hours, minute hand at 9. Restarted with hand at 3, stopped 20 minutes later. Took minute hand off, still running after 2 hours. I think the train is good to go, just too little power.
    Will install minute hand, add 1/2 turn to main spring and check again. This clock takes nearly 7 full turns. My other standard mechanisms will run happily at 2 turns and I sometimes forget to wind them fully before setting them back on the shelf. Maybe 2 turns on this one is just a little short. Once I find the minimum I'll let it go and see how long it will run before fully winding.
     
  19. KurtinSA

    KurtinSA Registered User
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    I forgot that was one thing I did...the clock was probably only 1/2 wound, so I went ahead for full wind. That might also be helping right now. I've heard about only winding a clock 1/2 way during checkout. If the clock will run on 1/2 winding, it should run for a year. The other side of that is that probably wind the clock to maybe 3/4 and rewind every six months...should keep better time.

    Kurt
     
  20. clksmyhobby

    clksmyhobby Registered User

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    Interesting. I have used the minimum power method for years. Have found that miniature movements, especially Kundo, usually need about 3 full turns to run consistently. I will observe rotation/over-swing as I step up the power on the SuP in half turn increments. Thanks for that insight.
     
  21. clksmyhobby

    clksmyhobby Registered User

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    The SuP ran fine overnight after I added 1/2 turn to the 2 turns I had before. Had 240° rotation with acceptable over swing. Went to 3 1/2 turns (about half full wind up) early this morning. Rotation now at 280°, over swing about 45°. Will leave it there and observe.

    Interesting post, Kurt.
     
  22. KurtinSA

    KurtinSA Registered User
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    Interesting to see the direct relationship between main spring winds and pendulum swings. I usually just wind my clocks to near full and live with what I can get. Hopefully it will run!

    The clock in question was running quite strong this morning. Near 340 deg rotation and over 45 deg of over swing. I figured that's all I can do, so I final oiled and assembled it. Now resides on the shelf until I find some more horizontal surface for display.

    Kurt
     

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