Help: Chatter on lathe, what's wrong

Discussion in 'Tools' started by Mac McCaskie, Aug 11, 2019.

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  1. Aug 13, 2019 #21

    Chiptosser

    Chiptosser

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    Shaun Free-

    This is very important, NEVER part pieces between centers, its not pretty if you try.

    Don't say this, This is commonly done, maybe not for your use but it is done.
     
  2. Aug 13, 2019 #22

    Cogsy

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    It's certainly not common in the home shop and can be a very dangerous practice. Personally, I would NEVER recommend such a practice to someone just starting in learning to machine, and personally I'd never even consider completely parting off between centres at all - too many bad things can happen. I think Shaun was giving very good advice to someone just starting out.
     
  3. Aug 13, 2019 #23

    XD351

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    Better to set up a steady to support the part rather than between centres when you are parting off from a long piece
     
  4. Aug 13, 2019 #24

    bluejets

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  5. Aug 14, 2019 #25

    Wizard69

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    It is important to understand the dangers in excessive stickout from the chuck. That can be a danger. Id suggest getting a book on how to run a lathe.

    Beyond that the Asian import lathes generally are not ready to run out of the box. I'd go into details but seem to be having significant video driver issues at the moment. there are however threads and youtube videos on the basics of starting up one of these lathes.

     
  6. Aug 14, 2019 #26

    larryg

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    Another thing to watch is your cut size. If you have a broad flat end on your cutter the chips will be wide and thin like a ribbon. This takes a lot of HP and rigidity. A small tip that produces a chip that is like a fine wire requires a lot less stress on the machine.

    If your cutter is a bit above center then if it flexes down it will move into the work piece and cut deeper exasperating your troubles. If your not on center then be a bit below so that the cutter will move away from the material and lighten the cut.

    Also understand that the machine twists and bends and absorbs energy while cutting. If it can release this energy and spring back it does. If it does this on a regular time period we call it chatter.

    lg
    no neat sig line
     
  7. Aug 14, 2019 #27

    IanN

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    Hi,

    Meant to include a pic of the “traditional” form of tangential tool

    IMG_4580.JPG

    The two tools in the middle are the tools to look at. The tool at the bottom is for a shaper and has the cutting edge arranged so it is level with the bottom of the tool shank - this will give you problems if you try to use it as a lathe tool

    All the best,
    Ian
     
  8. Aug 19, 2019 at 12:59 PM #28

    goldstar31

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    Actually, I've used ALL these types of tools both in a small lathe and a hand shaper but several things emerge.

    Almost certainly they will have been made from carbon steel and in the hands of a 'newbie' will be difficult to sharpen. I recall them in A.H Smith's Advanced Machine Tool book- which is available on the 'net for free. It's great book- a bit dated but it has stuff in it that doesn't often appear now. It's got some great maths stuff on tool grinding!

    Again on supporting materials for machining, I certainly agree with Cogsy about tail stock support but I would add the desirability of having things things like fixed and running steadies-- even if they are made out of wood.

    Thinking of holding things, we seem to have lost the catspaw chucks and 'Keats Plates'

    Now that my summer holidays in France are over I have to get back to the very humdrum but essential bit old cast iron -well Meehanite plate that I can pepper with tapped holes and drilled holes despite having lots of so called proper vises etc.

    Norm
     

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