M300 Tailstock Refurb- Boring and sleeve

  1. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

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    The tailstock on my Harrison M300 was badly bell mouthed, so over the last 5 nights I've been boring the tailstock out to take a 50mm phosphor bronze sleeve.

    The base had been hand scrapped in by Slideway Services, and was parallel to the bed, so if I wanted machine a taper then the top will still be on the same axis.

    I was lucky in that a mate had given me a 350x25mm Sandvik insert boring bar:whistle: a while back. So this was chucked up in a 200mm 4jaw chuck. I've never done this before so a Little head scratching and it was setup.

    The close up is after a few passes, taking almost bang on 23 minutes (need snoring doofer) for one pass at 180rpm
     
    • Boring bar.jpg
    • Boring bar close up.jpg
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  2. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

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    Finally got it bored out to size, and checked with a Mitutoyo Dial bore gauge, and was within 0.04 in its whole lenght:D

    So how to put put the Phosphor Bronze sleeves in.... well I've had this length of 20mm Acme threaded bar sat in the corner of god knows how long looking for a job.

    So they were shouldered to fit the sleeve and the end of the tailstock, to centre the bar.
     
    • Acme bar.jpg
    • Acme stepped nut 1.jpg
  3. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

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    Tailstock clamped in ali jaws in the vice. A pair of pump pliers and it was wound in, took some doing but it's in....
     
    • Winding in.jpg
    • Almost.jpg
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  4. wyn

    wyn Member

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    Nice work Shox.

    How did you move the tailstock towards the chuck when you were boring it out?
     
  5. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

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    Unfortunately that was only 1 of 2 sleeves :laughing: Might have to weld a socket to one of the Acme nuts, so I can put the windy gun on the end:laughing:
     
    • only halfway there.jpg
  6. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

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    Put it in front of the saddle, adjusted the camlock bolt so the powered feed didn't slip when locked it off, and ran it a 180rpm at 0.01mm feed. 24mins a pass:drunk::whistle: So only did a few per night.
     
  7. hotrodder Member

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    4,587
    SE England
    That is one very spoilt lathe :D I almost feel bad for walking away from mine tonight leaving the thing (as usual) half buried in swarf. In my defence cleaning it just reveals the rust and dings :laughing:
     
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  8. Pete.

    Pete. Member

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    Nice work Shox.

    I would have been very tempted to drill and ream a taper pin through the body and into the foot before boring that, so that it could be positively locked without off-set. Whether it would have worked or not is another matter...

    What made you choose PB for the ram?
     
  9. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

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    For the sleeve you mean. Because I knew where there was some:laughing:

    I did think about pinning, but forgot to be honest. And everything so far has gone fine, so as you say hopefully not required

    As for the molycoddlying its been treated to.

    A: it realy did need something doing. :o
    B: have you seen the price of 2nd hand ones:o:o that would still need fettling.

    And lastly I've never owned such a nice lathe, it deserves it:hug:
     
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  10. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

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    Almost there. Welded one of the nuts to the ACME bar and then a 20mm 1/2 socket,

    Welded AMCE nut.jpg

    I was going to use the windy gun but it's pants, so I used a 600mm breaker bar. took some doing but its in.


    Then in to the mill faced off: top and end.

    Facng end in mill.jpg

    I also installed a micro oiler nipple, these are from Manitou MTB forks. 5 pence for scale

    Oil Nipple 5p.jpg


    I also had to bore out for the keyway.

    reboring out for keyway.jpg Co-Axil Dial Indicator.jpg
     
    Last edited: Mar 10, 2013
  11. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

    Messages:
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    Location:
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    Back on the lathe, and pleasantly surprised, how little it was out. Most of what you see is from the first 1mm where the end was mushroomed from the fitting Picture shows swarf after taking a sighting cut, not worth measuring:clapping::D

    You can see a slight ring on the end face, where the Nut cut in, it happens that just about how much I need to remove, I tired to take a 2mm cut but it didn;t like it at all. You could see the tailstock moving. So reduced the cut to .25mm and stuck the dial guage on the bed reading onto the side, it moved less than a thou. I did the same to the top, with the same results, and... there was less than 1thou difference along its lenght. Whch i though would be the case as the mill slopes about 2.5thou over it's lenght. (but not for long):whistle:

    First cut on PB.jpg

    Not sure if this utube video will work but here goes.

    http://www.youtube.com/watch?v=1HJ94kBr9Bo&feature=youtu.be
     
  12. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

    Messages:
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    Location:
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    Wish I'd used something other than Phosphor Bronze, it's a pig to bore. What are your experiences with it Pete, or anyone else for that matter.
     
  13. Pete.

    Pete. Member

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    I dunno, it sounds like it needs to be more rigid. Did you use a new insert when starting the PB or the same one as used for the cast iron?

    What about clamping a flat plate to the tailstock top and loading it up with a couple of 56lb weights?

    I'd also consider knocking up a dummy tailstock, and finish turning that between centres. That bar hangs out a looooong way.
     
  14. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

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    For sure it needs more rigidity. I've had the boring bar for yrs, I can't remember the type of insert or if all sides have been used, certainly 3 have. I recon the bar is rock solid, its moving the tailstock after all. And I did think about a through bar but I havent built the steady yet.
     
  15. Pete.

    Pete. Member

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    It cut the cast iron ok didn't it? Maybe it's digging into the PB slightly on the cutting edge? Perhaps stoning a tiny land on the top of the insert where it's cutting would reduce that, the same way you would for a twist drill when drilling brass.
     
  16. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

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    Yes beautifully. I've justed the tool height, as it was above centre, and used a bit of cutting fluid and the results are much better. Still can't take anymore than a light cut.

    I've a 30mm x 500mm thompson bar I might cross drill to take a piece of Carbide, or HSS
     
  17. Pete.

    Pete. Member

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    I have some round stellite if you'd like a piece. It'd make a full pass without losing it's edge.
     
  18. Shox Dr

    Shox Dr Chief Engineer to Carlos Fandango

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    Thanks. What's the dia
     
  19. MattF

    MattF Member

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    Using something like that would be a far better option. Regarding a rear steady, just use a block of hardwood with a hole drilled through at the correct height to keep the bar centred, then clamp it to the bed somehows. A nice bit of oak or the like would make an excellent temporary steady. There must be a fair bit of flex on that boring bar, with the amount of it you have it protruding from the chuck.
     
  20. graffian

    graffian Seer unto the end of his beard

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    I was boring swinging arms, to weld in new bearing housings, it seemed a great way to make sure the bearing housing went in straight and looked neat but it was a real pain, however once I had started.... I was using a 32mm bar about a foot long to start with and the final cuts were something like a 1-3/4 bar with about a foot poking out, I am not sure they were ever thick enough. I was using HSS. I bought a rapidbore insert cartridge on ebay to make the boring bars for when I next do it.

    Bar as thick as possible, don't assume slow/small cut is best.

    Traveling steady sounds a good idea. I have a proper one[never used it] I recently needed one and I clamped a bit of steel in the rear toolpost, drilled a hole in it and used that as a steady, it worked a treat[the proper one was way to big]. I need a traveling steady to finish the job I was doing, one clamped in the toolpost was pain, I figure a steady made from a scrap of 6mm plate will do the job, if it flexes I will add a diagonal to the other side of the carriage. There should be holes in your carriage to bolt it to.
     
    Last edited: Mar 13, 2013
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