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Power feed when parting off, yes or no??

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  • Power feed when parting off, yes or no??

    When parting off in the lathe should the tool be fed into the work by hand or can the power cross feed be used? What speeds and feed rates should be used on steel?

    Malc.

  • #2
    It really depends on your experience, among other things.

    What it boils down to is Do You feel comfortable using the power?

    Comment


    • #3
      I typically feed by hand so I can constantly adjust the feed to maintain a reasonable chip-load and smooth cutting action. If I have a lot of parts to cut, I will take the time to find (usually by trial and error) a good feed-rate, working my way up until the chips come off smoothly. If you do use the power-feed, make sure to start gently and gradually increase the feed. Otherwise you could take an overly large bite and stall the lathe, damage the chuck, break the parting tool, etc...

      As far as speed goes: I go slowly, with lots of oil. Parting steel with HSS tools can get hairy in a hurry, so slower is better. Keep a hand on the power-feed lever to disengage it quickly if things start to bog down.

      Comment


      • #4
        It depends on a number of things:
        What type of set up
        How rigid your lathe is
        CArbide or HSS
        etc

        Your speeds and feeds depend on the tool
        If the piece is large and heavy I find it better to
        take over by hand for the last .100" or so and to have
        a way to catch the part. (rod held in the tailstock pushed through the work)

        I use flood coolant to 'flush out' the chips
        please visit my webpage:
        http://motorworks88.webs.com/

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        • #5
          Don't be frightened to use the tailstock for support.
          It makes a hell of a difference and contary to popular opinion the part doesn't jam up in the cut but just tilts to one side and stops rotating.

          .
          .

          Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



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          • #6
            Most of the parting I have done ay work was stuff like cutting through weld to remove drive line yokes so it was done by hand feeding.

            A cnc parts a bit fast but a multi spindle screw machine parts off at full speed and high rate of feed, it also has 100psi of cutting oil blasting on the part and tool though.

            Most of the problem people have parting is from too little oil and too far away from the chuck or collet.

            Comment


            • #7
              Originally posted by John Stevenson
              Don't be frightened to use the tailstock for support.
              It makes a hell of a difference and contary to popular opinion the part doesn't jam up in the cut but just tilts to one side and stops rotating.

              .
              I never use the tailstock for support as it does jam up the part at the end of the cut..

              I also use a carbide insert parting off tool and and always use power feed..

              Here is a short video I made years ago --->>> http://users.beagle.com.au/lathefan/...331%5b1%5d.wmv
              Precision takes time.

              Comment


              • #8
                Originally posted by Ringer
                I never use the tailstock for support as it does jam up the part at the end of the cut..
                I would be interested to hear other peoples remarks on this one - genuinely.

                I make gears for Myfords that Gert used to sell on Ebay.
                They are sold in pairs and I can cut 10 gears at a time on the Stevo E-Lec-tronic hobber.
                I normally make about 40 to 60 blanks one night after tea and cut them the following night.

                It actually takes longer to make the blanks than cut the gears.

                I take a piece of 30mm mild steel and drill it both end to just under 5/8", then ream it.
                I can then part off 8 gears from each end before running out of reamed bore.
                These are parted off on the CVA as it runs on neat oil and always followed up with the centre as additional support.

                Run out isn't a problem as the OD of all 10 are skimmed on the same mandrel that fits the hobber.

                Broke tools before but never had one jam because of the tailstock.
                Most problems are caused by me rushing the job.

                Also do worm wheels out of 3" brass and these are parted off the same but in brass it's not as much a problem as mild steel.

                .
                .

                Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



                Comment


                • #9
                  I always part off by hand and have(touch wood) never had a problem at the college club we were always told to use the tailstock as it was safer try making sure you are not using too much pressure on the tailstock or it could be a potential problem otherwise go ahead and watch your speed.Alistair
                  Last edited by Alistair Hosie; 03-01-2008, 05:42 PM.
                  Please excuse my typing as I have a form of parkinsons disease

                  Comment


                  • #10
                    I've not had a problem with the part binding when parting off with a tailstock supporting the work, but I don't do it with anything over about an inch in diameter. I've always assumed the risk went up greatly with larger diameters. For those, I part almost all the way through, then retract the tailstock to finish the last bit.
                    Cheers,

                    Frank Ford
                    HomeShopTech

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                    • #11
                      As far as using the tail stock It would depend on the application, and the length of piece cut off, Wouldn't it?
                      I have done both and I have used a rod in the tail chuck for washer type stuff.

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                      • #12
                        I always use powerfeed.
                        I could do it by hand but I'm too lazy, tired, dog ate my homework etc.
                        I sorta figured that's what that lever that makes the cross slide move was for.
                        I have tools I don't even know I own...

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                        • #13
                          To answer J S`s question.
                          I never use the tailstock to support the work while parting off as that`s what I was taught forty odd years ago.but I do use the power feed.But,machines and tools have moved on and I know a guy who always uses the tailstock and has never had a jam and he`s usually parting 3"-4" stainless with the power feed,in a Colchester which is not the best of lathes to part off in.I find there is more chance of chatter hand feeding than power feeding.It depends a lot on the machine but most people are frightened of parting off and run the work too slow and don`t feed heavy enough.I usually run the work at not much less than for normal turning.In an auto where I don`t have a choice it`s the same speed.Another thing that does not help is holding the job in a three jaw chuck,when the jaws are opened out for bigger diameters the work can lift between them and it`s curtains for the tool.Better in a four jaw or a collet.
                          Mark.

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                          • #14
                            I use the tail and a bullnose for pipe, keeps the chatter down. JRouche
                            My old yahoo group. Bridgeport Mill Group

                            https://groups.yahoo.com/neo/groups/...port_mill/info

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                            • #15
                              I like SOMETHING At the end for long parts. But just a "finger" type deal sticking into a hole, or a ring around.

                              An actual center seems to be no particular help, and maybe a bit of a jam-up, depending.
                              1601

                              Keep eye on ball.
                              Hashim Khan

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