Pivot Wear Too Much?

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  • #48455
    calhouns
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    • Topics Started: 4
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    I am new to clock repair and was wondering if there was an easy way to determin when a pivot is too loose and needs to be bushed?

    #52626
    willofiam
    Moderator
    • Topics Started: 75
    • Total Posts: 1437

    Calhouns, usually you can see it wiggling around in the pivot hole while the clock is assembled (after doing a few clocks you will get a good idea on what to look for) ;) , you can put reverse pressure on the great wheel with a key or you fingers and move the gear train back and forth, the worn areas will reveal themselves upon close inspection :ugeek:, or if you have captured the mainspring and let it down this all will be easier to accomplish. having the clock disassembled you would put the pivot into the corresponding hole in the plate and tip it in all directions. you dont want more than 5 degrees tilt in all directions, and of coarse you do not want it to tight either. One thing to keep in mind is that your pivots should be dressed up properly (polish out the grooves, properly formed, burnished) before determining whether the hole needs bushings or not, a pivot badly worn pivot will to quick damage to a new bushing 😯 . Sometimes after refurbishing a pivot you will have to put in a new bushing because you have reduced the diameter of the pivot. Bob also has some ideas on his videos on what to look for. hope this helps, have fun, William

    #52627
    arutha
    Participant
    • Topics Started: 85
    • Total Posts: 1536

    As Will states, the pivot must be made straight and polished before you start attending to wear in the plates. If the pivots are very bad and you need to remove a lot of material to get them parallel then they may even need to be re-pivoted. Just one word of caution, as William states most wheels can have 5 degrees of lean in the hole but make sure the escape wheel is a much better fit than that, its the one wheel that needs to be a good fit but loose enough to spin freely.
    If there is anything you dont understand please ask, we are always happy to help :)
    Paul.

    #52628
    calhouns
    Participant
    • Topics Started: 4
    • Total Posts: 10

    Thanks For the replies.

    Right now I am working on a Grandfather Clock that has an Urgos Movement in it. The background on this clock is, it belonged to a couple and the husband did not like it chimming, so he did something to make it stop. When I first looked at it, you could move the pendulum back and forth but the escape wheel would not turn. So I removed it from the case and found it was missing the suspension spring. I bought a replacement and I can make the escape wheel work, but it will only run for about 30 seconds and then it stops. I have disassembled the movement and cleaned it, and after assembling the movement, I did as was suggested in a previous post, I moved the great wheel back and forth and closely observed the pivots for wear. The escape wheel and the one next to it are showing no sign of wear. However the other three arbors in the train are a little looser, but it’s not like the holes are oblong. If I was to put a figure to it, I would say it’s less than .005 clearence. I will next polish the pivots and recheck the clearence. If you have any suggestions on how to work on Urgos movements, I would like to hear them.

    #52629
    willofiam
    Moderator
    • Topics Started: 75
    • Total Posts: 1437

    Howdy, I would assume your pivots are nickle plated, DO NOT take the plating off 😯 (in the previous post I was picturing some other type of movement 🙄 ), although you can polish these you have to be very careful and use a low abrasive polishing compound, FIRST take a look at the pivots and if they do not look like they are flaking or pitting, you can pretty much leave them, just clean them good, also if the clock is only running for 3o seconds I am thinking you have a different problem than worn bushings, I dont want to jump to conclusions at this point, (I can do that you know 🙄 ), check the rack and snail lifting levers ect…to make sure nothing is binding there, do some reading :geek: on the escapement and check to see if yours is set right. try to get some pictures on here, it would be great for everyone to see what your up to, I am sure you will have fun, just take your time and let us know what happens next. William

    #52630
    calhouns
    Participant
    • Topics Started: 4
    • Total Posts: 10

    Hey william, What you said hit the nail on the head. Instead of looking a pivot clearence I started to take a closer look at the escapement. Check out the photos I attached. It turns out the escapement was out of adjustment. After taking a few minutes to make some adjustments on the escapement, the clock started to run like a champ. :P

    Thanks for the suggestions.
    George


    #52631
    willofiam
    Moderator
    • Topics Started: 75
    • Total Posts: 1437

    Hey George, that is fantastic, :D Good job ;) Looking into escapement theory will put you ahead of the game, a lifelong learning process with clocks and watches, remember, a clock or watch that is not running can have several small issues that cause it not to run properly, each small issue steals away power to run properly, make yourself a checklist to go thru as you examine a non running clock, starting from the most basic and onwards, ie hands touching each other or the glass, pendulum, chain, pivots, sticky this and gummy that, ect…ect..to a properly set escapement. Have fun!!!!William

    #52632
    calhouns
    Participant
    • Topics Started: 4
    • Total Posts: 10

    Thanks Will ❗ :)

    #52633
    kennyheacock
    Participant
    • Topics Started: 2
    • Total Posts: 12

    Thanks for posting the picture. I see you have a newer Urgos with the Hermle style escape wheel. Mine has the urgos style with the mini-teeth. When I put mine together it was as simple as loosening the two screws in your photo and lifting the bracket up a little. I think the weight of the pendulum may move it down if you don’t assemble it tightly enough. Probably a little bit tough on the escape wheel! They probably should have been pinned unless that is an adjustment. Mine Urgos is a 660020A but is converted to a 32. Just a matter of the chime silence and select levers which had to come off the old movement to work with my dial. I managed to bend one of the pivots on a “fan” but took one out of an old movement. (The pivots are pretty crummy steel so be careful of that.) Mine’s in a Ridgeway. Bob has some good suggestions on the type of oil to use on the German movements in the clock troubleshooting PDF download.

    Kenny H.

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