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Thread: Bronze sleeves in a S/B 9" headstock

  1. #1
    Join Date
    Mar 2006
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    1,182

    Smile Bronze sleeves in a S/B 9" headstock

    I had mentioned this in another thread but I think it should be in a dedicated thread for archive/search reasons.
    A buddy gave me a 9" model A that was just collecting dust at his machine shop.(I'll return the favor by doing some work in his home)
    So first thing I did was totally tear it down. I figured I would start with the headstock and spindle.
    The bearings in the headstock were trashed. Badly scored on 100% of the bearing in the front and about 30% in the rear.
    I had read the article in HSM mag where a gentleman used his lathe ways to line bore the headstock in order to fit new bronze sleeves.
    I studied his method and it seemed sound. I had all the equipment needed for this task so I decided to give it my best shot.
    I used a mini mill head with a 1" diameter boring bar. The headstock was moved to the tailstock end of the bed where it was unworn. This is important as the line bore will only be as straight as the carriage can ride the ways.

    Here is what the headstock bearings looked like when I took it apart, ugly!-


    So here is the setup to line bore the front bearing-


    Here is the setup boring the rear, note the steady rest added -


    And here is the front bearing bored out ready for a new bronze sleeve-
    [
    The rear turned out just as good.
    Continued in next post,

  2. #2
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    Mar 2006
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    ok, so now it was time to turn some bronze sleeves. I used 660 bronze cores.
    This stuff machines easily. It sprays chips like rain. This is where you have to use all your skills and tricks as you need these to be nice and round, with a good fit to the head stock bores but oversized by about .0015" on the spindle journals. More on that later.
    I spent some time researching proper oil groove setup for plain bearings as well.
    Well first here are the finished bearings ready to be installed-

    I won't bother with all the tech involved in a plain bearing. But what I did learn is that what you do NOT want is a round bearing. This is why a certain amount of crush is used to create what is called a lemon shape. This shape helps control something called oil whirl and oil whip. Here is a primer on the subject-
    http://www.stiweb.com/appnotes/jb.htm
    And this is why my bearing sleeves were made a bit over sized in the I.D.
    I also studied oil grooved designs and went with a single axial groove 75% the width of the bearing.
    Now, here is where I made a big decision. This entire modification was a lot of work. Exacting work. One wrong move and your done and it's start over.
    The southbend oil wicking setup is nice. It was mainly designed to be very low maintenance. But it has some flaws. The oil the bearings is recycled and felt used to filter out the particles. And it does work of course and very well.
    However IMHO metered total loss system will be superior. It is adjustable, clean oil is always used and it's a simple matter of trying different oils
    So I went with top oiling. The original oil return holes will still function, the oil fills now become oil drains.
    There is no need to split the bearings. They are thin enough to lemon shape to take up clearance with the pinch bolt. With a setting of under .0005" clearance, the spindle still turns smooth as buttered silk. I set my clearance to .001" for initial run in.
    I checked run out and now understand Southbend quality. The spindle run out is better than all of my other machines that used ball or tapered rollers for spindle bearings. I have a hard to time seeing .0001" run out.
    So here it is all assembled and ready to once again make chips, I used Benjamin Moore industrial urethane enamel mixed to the formula on Tony's lathe site for a south bend.


    Steve

  3. #3
    Join Date
    Aug 2006
    Location
    Hesperia, CA
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    857

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    Steve, ya make me proud to be a painter. Apparently we're pretty good at this machine stuff. Well ... at least you are!

    SP aka "The Skinny Painter"

  4. #4
    Join Date
    Apr 2001
    Location
    Maine
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    That is one beautiful job! I like the oil cup mods, too.
    ----------
    Try to make a living, not a killing. -- Utah Phillips
    Don't believe everything you know. -- Bumper sticker
    Everybody is ignorant, only on different subjects. -- Will Rogers
    There are lots of people who mistake their imagination for their memory. - Josh Billings
    Law of Logical Argument - Anything is possible if you don't know what you are talking about.

  5. #5
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    Nov 2002
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    Central Pa.
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    How did you reach inside the bushings and cut that oil groove?

    mark61

  6. #6
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    Jul 2005
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    N W La.
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    Quote Originally Posted by mark61
    How did you reach inside the bushings and cut that oil groove?

    mark61
    Yeah, How DID you cut those grooves?

    Nice work, -- bet you did have some butt puckering moments before you finished!
    If everything seems to be going well, you have obviously overlooked something........

  7. #7
    Join Date
    Mar 2005
    Location
    Palmer Alaska
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    Nice job...

    Some one did the same to my 1936-7 9 in.

    It has total loss oil sytem like yours and I get wet running it...
    .
    No seal on outer edge lets oil run to backplate and sling all over the place ...

    If I had to cut those Oil grooves I would use the flex shaft and handpiece from my Dremal with a Ball or Lolipop cutter held in Milling attachment.
    Last edited by Bguns; 12-01-2007 at 08:41 PM.

  8. #8
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    Mar 2006
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    pntrbl, "skinny painter" It's a good trade! Met a lot of good people over the years! I do mostly residential work. Great word of mouth trade. I'm almost never out of work.

    Mark61,To cut the grooves I undercut a 1/4" reamer making it a t-bit head. Of course an endmill ground the same way would worked as well. I lightly clamped the shells vertically in my mill and used the modified t-cutter reamer bit to cut the grooves. 75% of the width.

    Steve

  9. #9
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    Jan 2006
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    Suffolk, England
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    Nice job Steve, and a good write-up as well. Top marks.

    On the spindle oilers, it looks you might have room to fit one of these on there:



    Which could give you a bit more control.

    Peter

  10. #10
    Join Date
    Dec 2004
    Location
    Western New York U.$.A
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    Great post! Thanks for the pics. Looks fantastic from here. Have you made any chips with it yet?
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