BUSHING QUESTION

Discussion in 'Clock Repair' started by NEW65, Jul 12, 2019.

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  1. NEW65

    NEW65 Registered User

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    Hi Chaps,
    Okay, I am sure we all have our different ways of re bushing the clock movements. My method involves no expensive machinery, in fact a lot of you people would probably think that my method would be doomed to failure every time!
    However, every movement that I have done has been a complete success with full power restored. My query is those of us who fit bushings(no matter what method is used) will probably need to ensure that the bushing is flush with the face of the inner brass plate.
    What do you people use to ensure this without making too much of a mess of the plate:???: Its easy to just get a flat file and trim the bushing until flush with the plate but that method finishes up scratching the plates just as abrasive paper does.
    Any comments would be useful?
    Thank you as always :)
     
  2. roughbarked

    roughbarked Registered User

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    #2 roughbarked, Jul 12, 2019
    Last edited: Jul 12, 2019
    By not pushing it past the plate.
     
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  3. Willie X

    Willie X Registered User

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    Yep, you press it in from the back using a large flat punch. It can't do anything other than stop exactly flush with the plate:???: Willie X
     
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  4. NEW65

    NEW65 Registered User

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    Okay - so what about the other end of the bushing - if it projects too far on the outside of the brass plate? Thanks :)
     
  5. David S

    David S Registered User
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    bullsfoot file.

    David
     
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  6. roughbarked

    roughbarked Registered User

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    Try selecting the correct bush for the plate. Otherwise shorten the bush before fitting.
     
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  7. Allan Wolff

    Allan Wolff Moderator
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    Use one of these round nose end mills in a large pin vise to cut off the excess bushing after it is installed. Makes a nice oil sink at the same time and blends in nicely with the plate. 2mm is a good size but you may want to get several sizes. They are only about $4 on ebay. Much cheaper than a set of oil sink cutters.

    rn-endmill.jpg
     
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  8. breeze

    breeze Registered User

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    You can place a piece of paper over the the bushing and surrounding area and file away without scratching the plate. Yeah I know but it works.

    breeze
     
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  9. wow

    wow Registered User
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    I use a bulls foot file.
     
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  10. mauleg

    mauleg Registered User
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    #10 mauleg, Jul 13, 2019
    Last edited: Jul 13, 2019
    +1 for the end mill. I get very clean results with mine. Please note, however, that the term "ball nose end mill" will provide better results in an Ebay search.
     
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  11. R. Croswell

    R. Croswell Registered User

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    I use a Bergeon "pivot cutter" (not what the name implies) like this one; Bergeon Pivot Cutter - 5.0mm The picture is one of the larger ones and Timesavers just uses the same picture for all. I mostly do American clocks and many do not have oil sinks so I intentionally use bushings that will extend beyond the outside of the plate and trim flush with the "pivot cutter". If I desire an oil sink I prefer to cut it myself with a tool I made that's essentially like the ball-end end mill described here by others. The pivot cutter does not work well if hand held but does a fine job in the Bergeon bushing machine.

    RC
     
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  12. shutterbug

    shutterbug Moderator
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    I use RC's method as well.
     
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  13. gleber

    gleber Registered User

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    How do you support the plate - do you have a recess or hole in the supporting surface that you can press the bushing into?

    Thanks,
    Tom
     
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  14. R. Croswell

    R. Croswell Registered User

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    The "stump"in the Bergeon bushing machine is hollow to allow the reamer to pass through the plate. After the hole is reamed (usually from the back side) the bushing is placed over the hole and the reamer replaced with the bushing pusher. The excess length of the bushing simply extends into the hollow stump. The plate is turned over so the excess length is "up" and the bushing pusher replaced with the pivot cutter. It isn't necessary to support the back side of the bushing with a solid stump, the same hollow stump will provide support for the plate. If the friction fit is correct the bushing won't move during the trimming process. The "oil sink cutter" then replaces the pivot cutter if that is desired.

    RC
     
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  15. NEW65

    NEW65 Registered User

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    Thanks everyone for the great advice - I just wanted my work to look more professional as there is nothing worse than seeing a lot of scratches/scuff marks around a newly fitted bushing!

    One last query on bushing:
    We all know that bushings should be fitted from the insides of the plates especially if using hand tools (broaches).
    If however one is drilling the holes out (with the correct size drill bit used for brass), then is it necessary to fit the bushings from the inside of the plates only or could they be fitted from the outside of the plates instead?
    I only ask because there is no tapered hole when using the drill bit?..
    Cheers chaps :)
     
  16. moe1942

    moe1942 Registered User

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    I use a Bergeon bushing machine..Ream all holes that will be bushed. Install a solid stump and tap the bushing in until flush with front of plate. I then use a standard 3/16 four flute end mill to trim any excess on backside...I don't like bushings protruding from the front and pivot cutters are too pricey for my liking..
     
  17. roughbarked

    roughbarked Registered User

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    #17 roughbarked, Jul 13, 2019
    Last edited: Jul 13, 2019
    Why buy an extra tool when a pin vice and a jewellers saw will fix all? Countersinking can also be done manually.
    How many bushes do you select that may protrude?
    When I saw the end off, I get an extra bush I can use somewhere else .. two for the price of one.

    Who among you actually calls yourself a watchmaker?
     
  18. Jerry Kieffer

    Jerry Kieffer Registered User
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    If you create a straight round hole and properly friction fit a bushing, removal resistance will be the same in either direction. Thus it makes no difference if it is installed from the front or the back.

    What has always puzzled me, is that if you create a tapered hole, why would you not use a tapered bushing:???:?? In this case with a tapered bushing in a matching tapered hole, resistance would be far greater than a straight bushing in a tapered hole. Thus , again, it would make no difference from the front or the back.

    Jerry Kieffer
     
  19. roughbarked

    roughbarked Registered User

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    correct
     
  20. roughbarked

    roughbarked Registered User

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    Man, I use various methods according to how much time I have in the day and according to what I think the customer wants to see.
    I will hand finish everything if the customer wants to see what I have done.
     
  21. moe1942

    moe1942 Registered User

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    Not me...Don't work on watches...
     
  22. Uhralt

    Uhralt Registered User
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    I have difficulties understanding this. I would think with a tapered bushing in a tapered hole it would be very difficult the press the bushing out to the smaller diameter side, but it should be possible to push it out to the larger side. Just like a tapered pin, I guess. What am I seeing wrong?

    Uhralt
     
  23. Jerry Kieffer

    Jerry Kieffer Registered User
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    Uhralt
    Your not seeing anything wrong. You are correct.

    What I am saying is that a tapered bushing driven into a matching tapered hole, will have at least the same resistance as a straight round bushing in a straight round hole properly fit.

    Since both properly installed far exceed the resistance required to stay in place during operation of the movement, it would make no difference on the direction they are installed. The only reason for bushing from the inside with tapered holes and straight bushings, is that when you create a mess, its wise to compensate for the consequences.

    Jerry Kieffer
     
  24. Willie X

    Willie X Registered User

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    A drill will always make a tapered hole and the interior of the hole will be very rough and uneven. Also, a drill (when drilling into thin material) will make a triangular shaped hole. There are a lot of things NOT going your way with a drill.

    Sooooo, get yourself one or more
    D-cutters to match the bushing system you prefer and many of your problems will go away.

    Willie X
     
  25. Uhralt

    Uhralt Registered User
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    Ah, I see. Thank you!

    Uhralt
     
  26. shutterbug

    shutterbug Moderator
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    A bushing pressed in from the inside of the plate will be seated with the base flush with the plate. That makes things a lot easier. If needed, the front side can be made even with the plate in various ways, and won't affect endshake like fiddling with the inside might do.
     
  27. R. Croswell

    R. Croswell Registered User

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    You are quite correct that straight bushings pressed into straight holes "far exceed the resistance required to stay in place". However, the leading edge of commercial bushings have a slight chamfer or taper to help guide the bushing into the hole. If the bushing is the same length as the thickness of the plate (a bushing pressed in from the inside does not extend beyond the front of the plate) then more force will be required to force the bushing through the front plate than is required to force it backward toward the inside. The metal behind the bushing has already been expanded, the metal ahead has not. It is therefore desirable to press bushings from the inside if one desires a small extra measure of protection which isn't really necessary. Perhaps that's where the "rule" press from the inside originated?

    RC
     
  28. Jerry Kieffer

    Jerry Kieffer Registered User
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    RC

    If you attend regional meetings, you will find very few meaning less issues that are not argued at a dinner table after hours. This topic is no exception.
    One night while at the St. Louis regional when it was held at the Breconridge Concourse, this topic became quite heated along with others. To settle the argument the next day at a mart table, one of the guys reamed two straight holes in a junk plate and installed two bushings. He then installed the plate under a arbor press (He had for sale) and hung weight on the handle until the bushing popped out. Then the next one from the opposite side. Took almost identical weight for either side.

    Pressing bushings from the inside based on the opinions that I have heard over the years, including the dinner tables during and after alcohol.

    Apparently, some figured out that when you insert straight things like bushings, pivots etc. in tapered holes, they more easily come out when under stress. Again apparently it didn't`t take long for some to figure out that if a bushing come out of a tapered hole (Or any hole) from the front, and if teeth lost contact, it often created more damage than they could deal with. Thus rather than deal with the issue, it was reasoned that if a bushing came partially out of a tapered hole held by a arbor from the inside during operation, it had far less chance of creating damage other than a dead movement.

    Jerry Kieffer
     
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  29. R&A

    R&A Registered User

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    This post took a turn didn't it. Wow some of you guys
     
  30. Kevin W.

    Kevin W. Registered User
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    R and A, it gets that way sometimes on the mb, i myself have my way and many others do, but when it comes to a argument, i dont participate.:(
     
  31. Willie X

    Willie X Registered User

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    I'm not taking sides on this one. Are there sides? Ha

    However, I have pressed in large numbers of big olite (or brass) bushings into equipment that would make a clock look like a mosquito. Anyway, many of these bushings are long, length being about 4 times the OD. The story is always the same. When you press them out, it might take 10 tons to get them moving but when they go past half way the press speeds up and they almost fall out. When you start to put in the new bushings, they go in easily for about an inch using a small lead mallet, or a block of wood and a 2# shop hammer. Then you put them in the press and it takes progressively more and more pressure to push them home. Half way may be at 2 tons and all the way in maybe 5 or 6 tons. This is always the same. Progressively more and more pressure to push them in and even more to move them back out after being in place for a year or two.

    I think this applies to clock bushings too. But with a tiny bushing the pressures and distances are so small we don't really notice what's going on too much.

    Willie X
     
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  32. bangster

    bangster Moderator
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    Why is this important??
     
  33. Organist

    Organist Registered User
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    Wow, wow, wow... LOL! This is a topic that sure stirs things up-- the best way to bush, making bushings vs. buying, machines vs, hand... We organists have topic that also stirs things up. It's called pipe vs. electronic. One group says the only real organs have pipes and all others are cr**. Then there's the group that says pipe organs are expensive and old fashioned, and can give you all kinds of reasons why electronics are superior. Then there's another group that says it doesn't matter either way. I guess at the end of the day, human nature is the same no matter what you do. :)
     
  34. R. Croswell

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    #34 R. Croswell, Jul 15, 2019
    Last edited: Jul 15, 2019
    Of course we both know that we are dealing with small differences in force and that hanging weights on the handle of an arbor press is hardly a precise test, and a single test doesn't prove a whole lot unless it can be repeated several times. It stands to reason that a straight bushing (with the factory bevel at the leading edge) disrupts the brass plate to some extent as the bushing is pressed in. If the bushing is stopped flush with the front plate the metal at the point of the bevel at the nose of the bushing has not been expanded quite as much. Therefore there is still a small amount of "less disturbed" brass ahead of the bushing. The expected force required to move the bushing ahead, through, and out of the plate should be greater than the force required to move the bushing backward and out of the plate. This potentially becomes a greater consideration as the thickness of the plate becomes thinner. I'm talking about a straight bushing, a straight hole, and a bushing pressed straight in with a bushing machine, or drill press etc. Bushings hammered in free hand may disturb the hole where they enter the plate this making the bushing less secure and indeed more likely to fall out the inside of the plate. A properly fitted bushing will not fall out regardless of which direction it is pressed in, I believe pressing from the inside is the desired method to ensure the bushing is flush, and for any small advantage that might be gained in retention. Of course if the bushing is proud of the outside of the plate there is no friction advantage but still more than adequate friction to retain the bushings.

    For tapered holes and straight bushings, hammered bushings, hand broached holes, etc. all bets are off.

    RC

    bush-1.jpg bush-2.jpg
     
  35. shutterbug

    shutterbug Moderator
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    Since bushings are a coupe of thousands larger than the hole they go into, there will be some forcing on both parts, the bushing and the plate, creating the resistance that RC refers to in the forward direction. Once the bushing has cleared the other side of the plate that resistance would be nearly equal both ways. In that case, a slightly shorter bushing pushed from the inside of the plate would have greater resistance to being pushed out toward the front. Yes?
    However, the only time I ever see this as an issue is when humans exert unnatural forces on a bushing - like when pushing a gathering pallet on. I've never seen one just fall out if it was properly sized.
     

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