Question about polishing pivots

Discussion in 'Clock Repair' started by Schatz70, Oct 29, 2019.

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  1. Schatz70

    Schatz70 Registered User

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    I've watched a bunch of clock repair videos on YouTube done by dperry428 - they are usually an hour to two hours long and are excellent for learning about how to repair clocks. He has a Sherline Model 4530 lathe that he uses to polish pivots and he often shows a pivot with grooves worn into it and then he shows it spinning in the lathe while he polishes it with emery boards. But he never shows how he mounts the wheel in the chuck of the lathe. Do you insert the end that you are not working on directly into the chuck? Or does the end you are not working on have to go into a jig of some sort to protect it before it goes into the chuck?

    Also if you don't have a lathe (and I don't), can you use a drill press instead?
     
  2. Willie X

    Willie X Registered User

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    Pivots have been polished by hand for 100s of years. Look up 'throw' or 'hand polishing pivots'. Willie X
     
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  3. R. Croswell

    R. Croswell Registered User

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    I use a Sherline lathe to polish pivots. Mounting the part can be challenging sometimes. Best NOT to grip the pivot on the opposite end. Sometimes the pivot being worked on is held in a wood or brass "runner" which is a round piece of wood or brass with a hole about the size of the pivot. Half of the stock is cut away to form a cradle for the pivot. The runner goes in a chuck in the tail stock. Sometimes the end of the arbor being worked on is held with a steady rest attached to the lathe. How close the pivot is to a gear or pinion can determine the method of choice. If a pivot is grooved or tapered or very rough a lathe allows you to turn it true with a lathe bit before polishing. Pivot files can also be useful in some cases. All sorts of contraptions have been used in place of a lathe. I would personally not use a drill press and definitely not a Dremel tool. The important thing is that the pivot be true and polished or burnished to a mirror finish with no grooves or scratches. There is no one way that is best for every situation. I think a lathe makes it a lot easier.

    RC
     
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  4. Rockin Ronnie

    Rockin Ronnie Registered User
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    Any chance of showing a photo or two of what you mean.
    Ron
     
  5. R. Croswell

    R. Croswell Registered User

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    There have been a number of picture poster to other threads by myself and others. A search for pivot polishing may turn up something. I'll be downing some pivots later this week, maybe I can take a few pictures.

    RC
     
  6. kinsler33

    kinsler33 Registered User

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    I've been using this thing:

    A bogus lathe to polish pivots

    for years now. I've since replaced the old pillow blocks with nice Chinese ones via eBay, and I've replaced the terrifying foot pedal control that originally came with the sewing machine motor with an electronic pedal controller. It's also very handy for weird drilling and grinding jobs because you can chuck most anything into that half-inch Jacobs chuck.

    M Kinsler
     
  7. R&A

    R&A Registered User

    Oct 21, 2008
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    Buy a lathe If you have a respect for this trade don't just get by Buy the right tools. You'll be better off in the long run.
     
  8. bangster

    bangster Moderator
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    Ain't got no steady-rest. You should rig one. :D
     
  9. Jerry Kieffer

    Jerry Kieffer Registered User
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    Schatz
    If a arbor section exists on the opposite end your working on, that can go into a collet or chuck as it is. On the other end, I most often use a runner to support the pivot that is mounted in the tailstock chuck.

    However, if no arbor section exists on the opposite end worked on, in most cases you can mount the wheel in the lathe chuck with the jaws reversed per first attached photo.
    In addition, this photo shows a runner for pivot support.

    Again in addition, the second photo also shows a ball bearing support for either a fine file, burnisher or whatever that assures that the pivot will be straight not tapered.
    The second photo shows a burnisher in place on the ball bearing support.

    Jerry Kieffer

    fullsizeoutput_41c.jpeg fullsizeoutput_41d.jpeg
     
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  10. Schatz70

    Schatz70 Registered User

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    That's a nice setup. Sherline seems to be the brand of choice for lathes used for clock repair.
     
  11. R&A

    R&A Registered User

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    Yes it would work if all the arbor are the same diameter each time I don't see where one would work for all your work. How many of these do you plan on making. Or are you just trying to sell another lathe for Sherline .
     
  12. kinsler33

    kinsler33 Registered User

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    We used to hear this at rec.crafts.metalworking in the late 1990's, and then the conversation would quickly deteriorate into just which tools were the Right tools. My own philosophy is to gather tools as you find them and learn to work with them rather than try to equip yourself with a complete clock repair kit at the start.

    I might also observe that I haven't seen any dedicated clock-repair tools of particularly good quality. This is not the case with other crafts like gunsmithing: a set of screwdrivers for that will really set you back. Watchmakers also seem to have better tools available than we do. In fact, the best tools I've seen for clock repair are those manufactured by the clock repairer himself.

    It's worth considering that while antique clocks are of limited complexity--that is, we're unlikely to see anything much more sophisticated than a Hermle grandfather movement--there are lots of technologies out there with tolerances and standards of cleanliness that make our best stuff look silly. Consider, for example, the optical systems used in the manufacture of the integrated circuits used in computers. When I was first introduced to these around 1980, the transistors deposited on silicon chips were on the order of 2 micrometers square. Today, the transistors are smaller than bacteria:

    process technology Definition from PC Magazine Encyclopedia

    and there are millions of them in your smartphone. And yes, there are mechanical systems that can deal with tolerances like these. Or consider the fuel-control system in an airliner's engine. It's electromechanical, very precise, and mission-critical, meaning that it cannot fail. Somehow I don't think the guys who repair these buy their tools from Bergeon.

    M Kinsler
     
  13. bangster

    bangster Moderator
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    My lathe, which I bought many years ago, is a Marshall watchmaker's lathe. At this point in my career, there would be no gain for me to invest in a Sherline or other "real lathe". If I had had one a decade or so ago, I could have done a lot more stuff (and maybe better). But given the volume of my work, there would have been no return on the investment. The Marshall does all I want or need to do, and that's good 'nuff for me. :)
     
  14. Jerry Kieffer

    Jerry Kieffer Registered User
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    R&A
    I am making the assumption that your comments were addressed to myself.

    The response in post #9 was in response to the OP for photo`s on holding arbors in a Lathe. What I showed could be adapted to other lathes. Items were made for my personal use and are not for sale since I do not sell anything.

    While the Chuck holds any size wheel and arbor under 3.250", I do not understand your Arbor comment. I suspect that you are referring to various pivot sizes in a movement.

    In Horology, runners have been used to support pivots for at least the last 170 years since I have a 1855 watchmakers lathe with one built into it. Many years ago, I made the one in the first attached photo that has 18 cavities easily rotated to whatever was required. Unfortunately, it turned out to be cumbersome, inefficient and I seldom used more than three cavities on the average mix of clocks I worked on. Thus, I started using individual runners because they allow far greater flexibility and are very easy, fast and simple to make.
    I simply drill a hole in the center and file half round or machine half round per second photo. I almost always machine them half round because center is quickly set by hand wheel setting and single pass machining only requires a few seconds. Again, I seldom use more than three since there is some flexibility in pivot sizes for a single hole size.

    Jerry Kieffer

    fullsizeoutput_45e.jpeg fullsizeoutput_45d.jpeg
     
  15. kinsler33

    kinsler33 Registered User

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    Two points:

    (1) I am and shall always be jealous of Mr Kieffer's craftsmanship, and I have always admired his willingness to share his experience.

    (2) I hope that everyone here will ignore any excessive grouchiness (beyond the usual) in my posts. Ten days ago I ran my motorized bicycle into a deeply-depressed manhole cover, which caught the front wheel and, according to the Lancaster Police Department, flipped me completely over the handlebars. I fractured a neck bone (#1 or #2, I'm not sure) and my collarbone, which rendered my left arm relatively useless. No permanent damage, but I'll be in a neck brace for six weeks.

    I haven't seen the bike and don't want to right now; at the moment I'm surviving on pain medication and dealing with the substantial physical and psychological shock as best I can. The bruised ribs are apparently an impressive sight as well: my wife gasped.

    I'm still repairing clocks, but very, very slowly, generally having to re-do each step because they tend to come out backwards.

    Thanks.

    Mark Kinsler
     
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  16. Bruce Alexander

    Bruce Alexander Registered User
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    Geez Mark!

    You trying to leave us early or something? :eek:

    How are you looking at small, detailed work with a fractured Cervical Vertebra and the use of one hand?

    You could easily not be here anymore. Glad that you still are.

    My wife fell on Columbus Day and broke her right upper arm into four fragments.

    She had surgery for plates and screws two weeks ago today.

    Slow down Man. Enjoy plenty of quality time with the Mrs.

    Is what I think.

    Bruce
     
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  17. shutterbug

    shutterbug Moderator
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    Yikes, Mark! I hope you recover quickly! I haven't noticed any issues with your posts :)
     
  18. Jerry Kieffer

    Jerry Kieffer Registered User
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    Hey Mark
    Get well soon. You will be in our prayers.

    For my part, I promise to lay off of the Harbor Freight comments until you get up to speed.

    Also, thank you as always for the kind words.

    Jerry Kieffer
     
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  19. Kevin W.

    Kevin W. Registered User
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    Get well soon Mark. We need you here posting.I have a Taig lathe and it has served me well, but i may get a Sherline one day. I buy the best tools i can afford, my wife thinks i am nuts but at least my money is in tools, not shoes.:p
     
  20. R. Croswell

    R. Croswell Registered User

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    Mark, I join with others wishing you a speedy recovery.

    RC
     
  21. kinsler33

    kinsler33 Registered User

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    Thanks, everyone. That means a lot.

    Mark Kinsler
     
  22. Bruce Alexander

    Bruce Alexander Registered User
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    He's a writer SB. I wouldn't be surprised to find out that he has some pretty sophisticated Dictation Apps/Software at his disposal. :)
     
  23. kinsler33

    kinsler33 Registered User

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    I never thought of that. There's some sort of voice-to-text program that comes with Windows 10, but I never tried it.

    Typically it's just me + keyboard, composing as I write, though once on a visit to my mother-in-law I wrote a column in longhand. My handwriting is approximately illegible anyway. At present my left shoulder is disabled but my left elbow and hand are okay. Return visit to the doctor comes on Monday.

    Al Takastch (sp. as usual) seems far more disabled than I'll ever be on his videos, and does a splendid job of teaching this stuff to the likes of me.

    Mark Kinsler
     
  24. Uhralt

    Uhralt Registered User
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    Have a speedy and complete recovery Mark!

    Uhralt
     
  25. shutterbug

    shutterbug Moderator
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    You were close. It's Takatsch ;)
     
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  26. R. Croswell

    R. Croswell Registered User

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    Ron, there are lots different ways to hold arbors for pivot polishing. I can't show them all but here are a few examples. If the pivot is in good condition and all you need to do is apply polishing compound or fine wet or dry paper by hand you can get away with things that are less than perfect. If you need to turn down a pivot (remove metal), or use a pivot file to get a pivot back to round, or if you have to bore the arbor for a new pivot, then it is important that the arbor run perfectly true and that it is supported as close to the pivot as possible.

    The first example shows a typical wheel and pinion where the wheel and pinion are more or less in the middle of the arbor. Easy to grip this in a 3-jaw chuck by the arbor and sometimes by the wheel hub if it is thick enough. 3-jay chucks usually do not run as true as a collet (also shown) which is preferred. Arbors are not always perfectly smooth and round so there may still be a little run out in some cases. Collets only fit one size arbor so it can get expensive. I like to use the steady rest close to the pivot if I need to machine the pivot.

    The most difficult pivots are those close to the wheel (or pinion) at the end of the arbor. There isn't enough arbor there to chuck in the lathe without chucking the actual pivot. Chucking a pivot is asking for trouble, especially if it is a small one. An alternative is to make a lathe dog as shown with a hole that fits the pivot. The pivot is supported but is under no load. This setup requires a steady rest and some "spacers" between the rest and the pinion to keep everything in place.

    The third example is a tape drive setup and a wooden runner to support the pivot being serviced. In this case a bushing (wood or brass) goes in the collet to support the pivot and tape is used to actually turn the part. The runner shown is Bamboo, but can be hardwood or brass.

    These are just suggestions and can be mixed and matched. I believe Jerry showed examples of making and using a brass runner.

    RC

    example-1-0.jpg example-1-1.jpg example-1-2.jpg example-1-3.jpg example-1-4.jpg example-1-5.jpg example-2-0.jpg example-2-1.jpg example-2-2.jpg example-3-0.jpg example-3-1.jpg
     
  27. David S

    David S Registered User
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    Awesome photography R/C. Nice examples of holding difficult wheel assemblies.

    David
     
  28. Rockin Ronnie

    Rockin Ronnie Registered User
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    Perfect RC. I have a 3-jaw chuck on my Taig lathe that works well for me. I had not considered a steady rest and can see how that would work well for pivot polishing. I have copied your photos into my personal file for future reference. Again, very helpful.

    Ron
     
  29. R&A

    R&A Registered User

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    With the right materials a steady rest would not be all the difficult to make
     
  30. R. Croswell

    R. Croswell Registered User

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    If you do make one be sure to make it large enough. The Sherline one is too small to place close to some larger wheels.

    RC
     
  31. Bruce Alexander

    Bruce Alexander Registered User
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    Very nice contribution to the Message Board RC. Thanks!

    I've been using RC's Lathe Dog method for a couple of years now and find it to be very helpful with difficult pivots. When my little drive arm broke off I came up with an approach to use elastics to drive the wheel. I wouldn't use it for any other procedure outside of pivot polishing but it does work well. Also, with the elastic band holding back the gear, there's no need to use washers or other hardware to keep the wheel from migrating away from the Chuck.


    Another method of holding Arbors like those found on governors (small pinions) is to use Collets and load the Arbor through the end of the Collet.
    This and other methods are described by Steven Nelson in his online Article which can be viewed here: Tid-Bit 16 - Gear-Holding Techniques - SNClocks The piece was also published in the October 2012 NAWCC Bulletin, starting on page 525
    Steven works on high-end Vienna Regulators and evidently spares no expense in equipping his shop but he does offer something for everyone.

    Regards,

    Bruce

    Washers:
    Washers.JPG

    Elastics without Washers
    Elastics.JPG
     
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