I have just purchased a Boxford Lathe

  1. eLuSiVeMiTe

    eLuSiVeMiTe Member

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    Don't regret swapping my noisy 1p for 3p well worth while
     
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  2. brightspark

    brightspark Member

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    yarm
    there is no vibration on a resiliently mounted motor . if the surface would need to be that accurate for a bearing surface you would either use a lap or surface grind it
     
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  3. Hopefuldave Intergalactic pot-mender

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    1,601
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    The Shed of Danger, surrey, England
    It's not just radial vibration from an out-of-balance motor, the torque developed by a three-phase motor is uniform for the full rotation: not so with a single-phase motor so there are instantaneous variations in angular velocity (at both 50 and 100 Hz) in both the motor and the driven parts (spindle, chuck, workpiece etc.) that result in variations in surface speed, which affects the cut and thence surface finish. Plus a VFD allows you to tune out resonances that lead to chatter and banding on the work - it's real and measurable, and a 3-phase motor drive leaves a lot less surface roughness to lap/cylindrical-grind if you need that good a finish, a better finish if you don't.

    Dave H. (the other one)
     
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  4. addjunkie

    addjunkie Member

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    Dont disagree, but hes not got a clue about basic turning, let him get it running and cutting metal before you all fill his mind with ideas and dread.

    Put machine in, clean it, oil it, and see if it works before you do anything else, then confuse yourself with ideas, even screw cutting isnt so difficult, but i will say as with most things, by all means read the book, but watch a video of someone doing it, makes it seem far less complex.

    I remember, buying a dividing head, hadnt used one in over 30 years, and wasnt interested when I did, read the book from when I was an apprentice, confused my self more, watched a video, all made sense, first toothed wheel was a sucess, except Id picked the wrong hole in the dividing plate, not wearing my glasses, so it 28 teeth not 29.
     
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  5. minimutly Member

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    Dividing head - now that's on my list of likes to have!
     
  6. Hopefuldave Intergalactic pot-mender

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    1,601
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    The Shed of Danger, surrey, England
    How to lose friends: I was lumbered with a barely-used 15" Walter rotary table before it went from workshop to the World's Best Skip... Need a bigger angle plate!
    Neither is a proper dividing head, but that and the 6" can do most of the same jobs?

    Dave H. (the other one)
     
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  7. eLuSiVeMiTe

    eLuSiVeMiTe Member

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    Picked up a division master to drive my RT with a stepper. Can't see the need to invest in a dividing head with that setup.
     
  8. 123hotchef Member

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    9,499
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    Kent
    you guys have gone way over my head now! lol,
     
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  9. eLuSiVeMiTe

    eLuSiVeMiTe Member

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    Dividing head does exactly what it says. Divides a circle into x divisions for gear cutting, spline cutting and equal hole spacings etc.
    Rotary table is turned via a worm drive and handle but only uses a scale near the handle to show rotation amounts so not as accurate or easy to advance set amounts.
    My table will be driven by a stepper motor so I can click divide into 32 and everytime I hit advance it progresses 1/32 should reduce human error. Could you imagine stuffing up a 127 tooth gear on the final few teeth.
     
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  10. MattF

    MattF Member

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    But, a good countershaft unit can mitigate that to a large degree. If you have some fair weight in the pulleys, it's acting like a flywheel. That's why treadle mechanisms worked so well. The flywheel/pulley is so damned heavy, they're quite smooth in operation.
     
  11. 123hotchef Member

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    9,499
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    Kent
    An I was worried about finding the center of some bar to bore out
     
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  12. eLuSiVeMiTe

    eLuSiVeMiTe Member

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    Invest in a DTI and stand for clocking parts true in a 4 jaw. Plenty of how tos of the above on YouTube.

    If the bar is oversized its irrelevant. Stick it in a 3 jaw. Face the end off flat and drill with a center drill in the tailstock chuck. Then drill/bore to size. Turn the outside to size and your hole will always be central. If you remove the part from the 3 jaw and need to pop it back on the lathe clocking it true in a 4 jaw comes into play.
     
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  13. pressbrake1

    pressbrake1 Forum Supporter

    Messages:
    2,418
    essex england
    You right and wrong at the same time. Breaking degrees up into minutes and seconds and keeping count with a split degree division would be a nightmare that’s why you have dividing plates.
    I’m not saying your gadgets isn’t cool though.
    Real accuracy comes from encoder set ups with 50k divisions in the circumference
     
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  14. 123hotchef Member

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    9,499
    Location:
    Kent
    I have a couple of dti gauges and a magnetic stand for them
     
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  15. eLuSiVeMiTe

    eLuSiVeMiTe Member

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    Oh I don't disagree at all but for me and what il be doing with it its good enough.
     
  16. eLuSiVeMiTe

    eLuSiVeMiTe Member

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    11,651
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  17. MattF

    MattF Member

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    10,091
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    South Yorkshire, England
    The simplest way to learn on a lathe is to just start using it. When you come across something you're unsure of, or a task which isn't working as expected, then is the time to read up on it or watch videos. That way, you already have the basic concept in your mind, and the revision is just tweaking your method. If you do the revision before ever attempting the task, you're getting the info but have no experience to measure it against, so it can be confusing. Books & videos are better thought of as reference/guides rather than teachers.
     
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  18. Pete.

    Pete. Member

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    With a VFD you can set a gentle decel and reverse accel.
    If you have a 0.001" gauge use that in favour of a 0.0001" or you'll drive yourself mad trying to clock stuff in to an unrealistic reading. Also remember that a 4-jaw holds stuff very tight and it's easy to make a hollow round part go 4-lobed by gripping it too hard. You'll notice that many 4-jaws have what seems to be very small adjusting screws for the jaws (and the squares are often cracked or broken). That's because they don't need barring up like a wheel nut.
     
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  19. eLuSiVeMiTe

    eLuSiVeMiTe Member

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    I may have squashed a part after spending an hour boring it out in the past. Only once mind.
    It's only a balls up if you don't learn from it.
     
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  20. 123hotchef Member

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    9,499
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    Inches what are they lol
     
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