bushings

Discussion in 'Clock Repair' started by 010008, May 20, 2019.

  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  1. 010008

    010008 Registered User
    NAWCC Member

    Oct 25, 2009
    11
    0
    1
    Hello all, I have a Customer’s Gilbert mantel clock that had some unusual bushing repairs from a previous unknown repair person. A couple of pictures are attached. Rather than just punch the holes closed, this repair involved drilling multiple small holes just outside the oil sink. Then the worn holes were closed using the hammer technique. I assume the person was skilled enough to disassemble then assemble the clock because the plates were hammered on both sides? I was concerned about installing new bushings because of the small drill holes interfering with the new bushing hole. With polished pivots (they were quite scored) and 20 bushings the clock is up and running great.

    Has anyone else seen this type of repair? Thanks, Dave

    upload_2019-5-20_9-40-58.jpeg

    upload_2019-5-20_9-41-40.jpeg
     
  2. JST

    JST Registered User
    NAWCC Member

    Jun 29, 2003
    240
    2
    18
    Male
    Country Flag:
    Region Flag:
    I've never seen anything like what you have there. One would think the integrity of the brass around the pivot holes would have been compromised by the drilling. But, it sounds like you were able to install new bushings and get everything running. Good job. Thanks for sharing.
     
  3. bruce linde

    bruce linde Technical Admin
    NAWCC Member

    Nov 13, 2011
    5,931
    583
    113
    oakland, ca.
    Country Flag:
    Region Flag:
    there have been other such examples posted over time... the sad part is that that 'fix' took way more time and energy than bushing by hand.
     
  4. Uhralt

    Uhralt Registered User
    NAWCC Member

    Sep 4, 2008
    4,267
    449
    83
    Country Flag:
    Region Flag:
    I don't understand the rationale for making the holes? It wouldn't make closing the pivot hole any easier.

    Uhralt
     
  5. disciple_dan

    disciple_dan Registered User

    Mar 10, 2016
    434
    25
    28
    Male
    Clockmaker, General Flunky
    Apopka, Fl.
    Country Flag:
    Region Flag:
    Unbelievable!!
     
  6. Willie X

    Willie X Registered User

    Feb 9, 2008
    12,427
    836
    113
    Well,
    How did you fix the holes? Punching is common but I've never seen any drilled holes. There's never any need to upset metal on the unworn side of a pivot hole.
    WIllie X
     
  7. 010008

    010008 Registered User
    NAWCC Member

    Oct 25, 2009
    11
    0
    1
    Thanks for all the comments so far. I agree Bruce. Some of the small holes almost look as if they were "indexed" on a machine because of the equal spacing. Way too much time to do it this way and only headaches for the next person to repair.
     
  8. kinsler33

    kinsler33 Registered User

    Aug 17, 2014
    3,034
    287
    83
    Male
    Science teacher, writer
    Lancaster, Ohio, USA
    Country Flag:
    Region Flag:
    If you expanded those small holes with a conical punch it might tend to close the worn pivot hole. That could have been the theory, and if it didn't work he or someone else would have just closed the pivot holes with a punch. Assume that the clock wasn't worth much at the time of the experiment.

    I wonder how many dead serious clock repair people have tried experiments that turned out to be dumb. The most creative and ultimately productive people I've met all seem to have long histories of inadvisable research projects, typically but not always done when they were young.

    M Kinsler

    It is not a very good idea to place a shotgun primer on a fork so you can hold it over a gas stove burner.
     
  9. shutterbug

    shutterbug Moderator
    NAWCC Member

    Oct 19, 2005
    41,674
    902
    113
    Male
    Self employed interpreter/clock repairer
    Iowa
    Country Flag:
    Region Flag:
    Is there a story here, Mark? :D
     
  10. R. Croswell

    R. Croswell Registered User

    Apr 4, 2006
    9,674
    655
    113
    Male
    Trappe, Md.
    Country Flag:
    Region Flag:
    I think he means that regardless of how stupid an idea may be, there's always some jackhorse that's ready to try it.
     
  11. David S

    David S Registered User
    NAWCC Member

    Dec 18, 2011
    7,174
    237
    63
    Male
    Professional Engineer - Retired
    Brockville, On Canada
    Country Flag:
    Region Flag:
    It is interesting how our initial reaction depends on our previous experiences. When I saw that my first reaction was "oh and air cooled bushing".

    You see back when we made the transition from aluminum housings to polymeric for power tools we found out pretty quickly that the same old impregnated bronze bushings we pressed into the aluminum weren't going to cut it directly in plastic. So the bushing was pressed into a "heat sink" and the assembly was insert moulded into the plastic housing. This provided air passages around the bushing to remove the heat.

    B&D bushing with heat sink.jpg

    Now I know that isn't the case here but it quickly brought back memories.

    David
     
  12. R&A

    R&A Registered User

    Oct 21, 2008
    4,171
    99
    48
    Country Flag:
    Imagine that HUH. Who would do such a thing
     
  13. MartinM

    MartinM Registered User

    Jun 24, 2011
    3,031
    95
    48
    Male
    Medical Insurance Systems Analyst
    El Dorado, CA
    Country Flag:
    Region Flag:
    Was working with a friend one time who had to quickly fit a bearing on a shaft using heat and didn't want to chance it cooling too much in the time it takes to turn off the acetylene torch. So he simply snuffed the torch and dropped it on the table to install the bearing.
    The bearing on, he forgot about the torch that had been pumping a neutral flame mixture into the bin under a hole in the center of the table where cutoff parts were deposited. I was at another table and started grinding in that general direction and...

    I was sure we had all died in the explosion. After we dusted off all the stuff that came out of the rafters of the shop and could hear each other again we figured out what had happened. We learned how to do this with balloons and paper bags for livening up a party. Super loud, but no real energy. It's so fast if you do it in a plastic kitchen garbage bag, it turns the bag into powder, but at just a few feet from the event, it does no real 'damage'. A glass placed within a few feet doesn't get broken. Your eardrums might, though. The things we learn in a misspent youth.
    Please do not try this at home!
     
  14. 010008

    010008 Registered User
    NAWCC Member

    Oct 25, 2009
    11
    0
    1
    Glad I was able to bring up some good memories.
    David S - I like the idea of the air cooled bushing although there probably isn’t too much heat generated in a clock bushing. My first thoughts were a new and improved way to work harden the brass rather than just punch it closed.
    MartinM - interesting about the acetylene and fortunate that no one was injured. I recall hearing about when navy ships lowered the flag at sunset they would fire an acetylene canon. Not sure how true but the one I heard was loud.
    Dave
     
  15. bangster

    bangster Moderator
    NAWCC Member

    Jan 1, 2005
    19,501
    359
    83
    utah
    Country Flag:
    Region Flag:
    Beats the expense of gunpowder.
     
  16. TEACLOCKS

    TEACLOCKS Registered User
    NAWCC Member

    Mar 22, 2005
    2,225
    65
    48
    Male
    Clock service & repair
    Santa Rosa Calif.
    Country Flag:
    Region Flag:
    Those small holes around the bush hole are drilled all the way through the plates :???::???::???:
     
  17. kinsler33

    kinsler33 Registered User

    Aug 17, 2014
    3,034
    287
    83
    Male
    Science teacher, writer
    Lancaster, Ohio, USA
    Country Flag:
    Region Flag:
    There were no injuries except to the fork, whose tines were bent into an artistic sculpture. The sound was close enough to that of a gun shot that nobody in or around my questionable rooming house felt it advisable to investigate.

    And Mr Martin M. is a splendid writer.

    M Kinsler
     
    MartinM likes this.
  18. R. Croswell

    R. Croswell Registered User

    Apr 4, 2006
    9,674
    655
    113
    Male
    Trappe, Md.
    Country Flag:
    Region Flag:
    Taking a closer look at punched/drilled holes around the pivot holes I have to wonder for several reasons if any were actually drilled. Looking at the whole plate it is clear that some of the holes were prick punched and not drilled. I have seen plates punched so severely that the punch penetrated the plate completely. The holes around the pivot hole for the fan which appear to go all the way through the plate appear to have disturbed the metal leaving a slightly raised rim around the hole. I would not expect to see this if the hole was drilled. If the same person did all of this, why would he or she punch some of the holes and drill others? I see no logical reason for doing so as drilling would accomplish nothing. Some of the punchings are too far from the pivot hole to have any effect anyway. I suspect it all the work of an inexperienced uninformed repairer.

    Dave, how did you cope with the "holes" when you installed bushings? Can we see some pictures?

    RC
     
  19. Willie X

    Willie X Registered User

    Feb 9, 2008
    12,427
    836
    113
    From post #6, how did you fix it?
    Willie X
     
  20. dad1891

    dad1891 Registered User

    Feb 28, 2014
    581
    21
    18
    Male
    Denver, Colorado
    Country Flag:
    Do you realize how close your were to inventing the automotive air bag actuator?
     
  21. shutterbug

    shutterbug Moderator
    NAWCC Member

    Oct 19, 2005
    41,674
    902
    113
    Male
    Self employed interpreter/clock repairer
    Iowa
    Country Flag:
    Region Flag:
    Another missed opportunity! :D
     
  22. 010008

    010008 Registered User
    NAWCC Member

    Oct 25, 2009
    11
    0
    1
    The bushing installation involved using KWM 2.7mm which put the OD just inside the previous repair holes. The bushings were taller than the plate thickness so they stuck out slightly. Since I was going to broach/smooth broach, I punched each bushing effectively compressing the oil sink with the idea that this would help “lock” the bushing in place. I then cleaned up the oil sinks so they looked good. The bushings were secure during he broaching process so I feel pretty good they are going to stay put. I considered using double bushings but the diameter necessary would have put the OD outside the edge of the plate on about half the bushings. The only bushings that actually touched the previous repair holes were for the verge. I assumed there would not be a lot of stress here and the bushing would hold. I also considered using tix solder but don’t like to heat the plates unless absolutely necessary.

    Regretting not taking pictures of the finished product. I really didn’t expect the number of responses. Thanks to all for interest and comments. Dave
     
  23. R. Croswell

    R. Croswell Registered User

    Apr 4, 2006
    9,674
    655
    113
    Male
    Trappe, Md.
    Country Flag:
    Region Flag:
    Everything will probably work if you don't mind the unsightlyness of the punched/drilled holes. There shouldn't be any need to solder a bushing that fits properly. There options to fill the holes but not so good after the fact. The usual is to use a large enough bushing. I suppose you could have taper broached each hole and driven snug a tapered pin and dressed the plate smooth but wouldn't be easy to match the color, and it this case it would take a lot of pins.

    RC
     
  24. kinsler33

    kinsler33 Registered User

    Aug 17, 2014
    3,034
    287
    83
    Male
    Science teacher, writer
    Lancaster, Ohio, USA
    Country Flag:
    Region Flag:
    It's never a bad idea to rivet in a press-in bushing if (1) it extends outside the plate surface and (2) you don't trust it--i.e., it pressed into its hole too easily and thus can fall right out. While it is true that a properly-fitted press-in bushing will remain secure (at least until it is replaced) and that the reamers are carefully made, the bushings themselves occasionally are not. Presumably bushings are made on automatic screw machines and their outside diameter, while critical for us, isn't always of tremendous concern to the machine operators and to the inspectors, if any.

    Undersized bushings seem to come along more frequently, and they can be dealt with by riveting, by banging the hole shut a bit, or with a shot of green penetrating Permatex thread locker. When they come oversized, which has happened to me a time or two, it's somewhat tougher, for you can easily bung up both hole and bushing when you try to press it in.

    I've told the story about my experiences with press-in bushings when they were first introduced in the 1960's, and I can't say that my confidence in the system has improved much since then. But I still use them because they're faster than other approaches, though as an experiment I did make something like eight old-fashioned riveted-in bushings (sawed out of bushing wire) for a time/strike clock a few months ago and the work went rather smoothly.

    My sense is that press-in bushings are a transitional technology in horology that'll be discarded (and likely condemned as akin to Rathbun bushings or the hole-closing punch) not many years in the future.

    M Kinsler

    considering no-drill squeeze-in polymer bushing technologies.
     
  25. Willie X

    Willie X Registered User

    Feb 9, 2008
    12,427
    836
    113
    Dave,
    I was thinking that the drilled holes might be too close to the pivot hole and you would have used some method to fill the drilled holes. Glad that wasn't the case. Willie X
     
  26. Bruce Alexander

    Bruce Alexander Registered User
    Sponsor NAWCC Brass Member

    Feb 22, 2010
    6,108
    391
    83
    Country Flag:
    Region Flag:
    While something "better" may come along, I seriously doubt that the pre-manufactured bushing systems in use today will ever be "condemned" as something akin to pre-manufactured Rathbun bushings. One approach requires disassembly. The other does not.
     
  27. R. Croswell

    R. Croswell Registered User

    Apr 4, 2006
    9,674
    655
    113
    Male
    Trappe, Md.
    Country Flag:
    Region Flag:
    #27 R. Croswell, May 23, 2019
    Last edited: May 23, 2019
    I agree, the press-in bushings (and even hand made riveted in bushings) function by replacing worn away material and returning the clock as close as practical to the way it originally was before it the wear occurred. "Rathbun bushings" and similar systems cause a greater departure from the original design, and even additional damage that can be difficult to reverse. There may be room for improvement in the way press-in bushings are installed, but I believe that pressed in brass bushings will be the standard for repairing worn brass plates for the foreseeable future.

    I'm not sure about the "no-drill" part but polymer bushing technology is already available for some applications. For about 13 years I've been using an acetal homopolymer with 12% Teflon fill (Delrin-AF®) to bush worn pivot holes in wooden movements. The material is inexpensive, has very low friction, and requires no lubrication. If someone comes up with a dependable system for retaining these bushings in thin brass plates it might be a contender to replace brass bushings.........and maybe not.

    In a wooden movement, these are faster and easier to make/install, require disturbing less original material, and usually result in improved overall performance of the clock. They are also easy to replace if they ever do wear out, and do not preclude the option of replacement with wood, bone, or whatever if one so chooses. However, most of my previous posts about Delrin-AF® have resulted in some blowback from "purists" who are locked in tradition and not about to accept anything new or different from the way they have done it for decades. We've seen the same reluctance by some in the Horological community to accept modern adhesives, chemical locking compounds, and the like. I suspect that even if a reputable manufacturer came up with a system using "polymer bushing technologies" for brass plates, even it promised superior performance and longer life, it probably would not be welcomed or generally accepted.

    RC
     
    NEW65 likes this.
  28. shutterbug

    shutterbug Moderator
    NAWCC Member

    Oct 19, 2005
    41,674
    902
    113
    Male
    Self employed interpreter/clock repairer
    Iowa
    Country Flag:
    Region Flag:
    Personally, I don't mind any repair that can be easily undone in the future. It's the permanent bodges that bug me - like the Rathbuns, and stuff that's added where it shouldn't be. If a shortcut is taken that a future purist can reverse, and no permanent damage has been done, I'm OK with it.
     
  29. MartinM

    MartinM Registered User

    Jun 24, 2011
    3,031
    95
    48
    Male
    Medical Insurance Systems Analyst
    El Dorado, CA
    Country Flag:
    Region Flag:
    A possible future repair option might be 3D printed or CNC'd plates made from a scan of the original.
     
  30. kinsler33

    kinsler33 Registered User

    Aug 17, 2014
    3,034
    287
    83
    Male
    Science teacher, writer
    Lancaster, Ohio, USA
    Country Flag:
    Region Flag:
    I won't use Rathbun bushings either, but I don't see the inherent virtue in a bushing method that does not require disassembly.

    The bushing systems in use today would benefit from some improvement in any event. For one, the outside diameters on KWM should be standardized instead of being weird. And I have yet to appreciate those pre-drilled oil sinks. If I want oil sinks, which I generally don't, I'll drill them myself.

    Mark Butterworth has attempted to reform bushing systems (including taking the measures I've mentioned) for some years now. I don't know of anyone else who is interested.

    Mark Kinsler
     
  31. Bruce Alexander

    Bruce Alexander Registered User
    Sponsor NAWCC Brass Member

    Feb 22, 2010
    6,108
    391
    83
    Country Flag:
    Region Flag:
    #31 Bruce Alexander, Jun 7, 2019
    Last edited: Jun 7, 2019
    Well my Friend, I think it would be difficult to find a steady supply of them but I could be wrong.
    If a pivot hole needs to be bushed, don't you think the pivot should be evaluated and finished too? What good is a new bushing if the pivot is worn and rough? Sure, you'll reposition the pivot on center but the new bushing will probably wear quickly. Mark Butterworth has often said that one of the most important steps of placing a bushing is refinishing the pivot. You obviously can't do that without disassembly.

    Edit: There's also the matter of pegging existing pivot holes to remove as much contamination as possible before putting the movement back in service.

    If you are cutting your own oil sinks, a Ball Nose End Mill works well without removing too much brass, otherwise go with pre-formed sinks or no sinks if none were original to the plate.
     
  32. kinsler33

    kinsler33 Registered User

    Aug 17, 2014
    3,034
    287
    83
    Male
    Science teacher, writer
    Lancaster, Ohio, USA
    Country Flag:
    Region Flag:
    Rathbun bushings are still available, but I don't recall just where I saw them. Screw-in bushings, too. I wonder how many tons of stuff S Larose had on hand at its end. I once bought an assortment of emergency pivots, but I learned to re-pivot with more orthodox methods when I realized how much trouble they must be to use.

    You and Mr Butterworth are correct, of course. I make sure that every pivot gleams, which is easy enough to do with a 6/0 buff, even after you've ground off any suspect plating with the 1/0 buff and employed its six relatives: 2/0,3/0,4,0,and 5/0, in that order.

    Before I knew about plated pivots I did a Kieninger grandfather clock which I'm going to have to re-do after 3 years. I'm not sure that the pivots are at fault, but it seems likely.

    On the other hand, I'm finding that hole pegging doesn't dislodge much, if any, crud from pivot holes: the toothpicks stay clean. That may have to do with Zep Fast 505, my rather aggressive cleaning solution, along with 30 minutes in the ultrasonic cleaner, with heat to 50C. Growl.

    Mark Kinsler
     
  33. Bruce Alexander

    Bruce Alexander Registered User
    Sponsor NAWCC Brass Member

    Feb 22, 2010
    6,108
    391
    83
    Country Flag:
    Region Flag:
    #33 Bruce Alexander, Jun 8, 2019
    Last edited: Jun 8, 2019
    This is what Mark writes on page 48 of his book "A Modern German Clock Movement"

    I'm really starting to like his pivot polishing 3-disc system on larger pivots like those found in many American 8-Day T&S movements. They are relatively inexpensive and very fast. The biggest downside I've read is that they don't get all of the way into the corner of the shoulder formed by the pivot and the end of the arbor. If you keep the disc dressed you can get in fairly close to the arbor. I also like to orient the disc from perpendicular to the pivot to parallel to it and work in as close to the shoulder as I can. This also polishes the shoulder as well as the pivot. If you're in the habit of placing a shallow chamfer on the inside diameter of a bushing or pivot hole, the "corner" between the pivot and arbor will probably not come into play anyway while plate friction with the larger shoulder does represent a significant loss of power as you go through the entire gear train.

    Another potential downside to his system is that it is easy to lose (or fail to re-establish) the parallel sides of the pivot.

    His mandrels are a little flimsy too. I'm thinking of replacing them with Dremel brand mandrels which are a little thicker and should stay true better. The discs start out fairly large so you have to be careful handling them or you'll bend your mandrel.

    Technically, he says it's grinding, so I usually wear a mask just because I get fairly (too) close to the action and don't want to breathe in any airborne materials.

    Regards,

    Bruce
     

Share This Page