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Tapping/threading on a turret lathe?

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  • Tapping/threading on a turret lathe?

    Hey guys! I'm mulling over how I want to set up this lil' turret lathe.
    Here's where I'm at so far...I've taken a lot of the machine apart and cleaned it up. I'm thinking of changing out the motor. I'm going to buy a set of 5C collets. Also going to buy 3 drill chucks for it (with arbors...they are too cheap to bother making).
    So...what about tapping/threading? The lathe has no provision for "slippage" so I'm assuming I'd use a (smallish)tapping head for tapping?
    And what about threading with dies? This machine has a 125 rpm low limit (2800 high). I'd like a newer motor with rocker switch but there has to be a better way....no? What is a floating die holder? Is that what I should use?
    I'm thinking a 5/16" tap/die set is the largest I'd run on this...time will tell I think.
    This should fill the turret positions...three chucks...one for spot drill, one for pilot drill, one for tap drill, tapping holder(?), die holder and a bar stop.
    The cross slide...I'd like to set that up with a chamfer cutter and an upside down cutoff blade.
    Thanks!
    Russ
    I have tools I don't even know I own...

  • #2
    Russ, you have a lot to learn about turrets.

    First they make a Tap head,and Die head for T/L's.

    What size holes in the turrets?

    Your Chamfer setup can be on any drill poss. This frees up a tool poss.,and that saves time/Money.

    Comment


    • #3
      A tapping head, such as Tapmatic, isn't going to work. What you need is a small W&S tap driver. I think Hardinge, B&S, etc also made/make these heads. They can be set for R or L hand threads, and work on a single tooth pull off type clutch. You set the depth stop on the ram, and when you reach the stop, the head pulls off of the single tooth clutch and spins with the work. To back the tap out of the work, you have to reverse the spindle and retract the ram, but make sure the head re-engages the single tooth clutch before retracting. You may/should set the driver in an adjustable holder for proper centering.
      For external threads, I recommend a Geometric 5/16 or 9/16 style D die head. Ebay would probably be your most economical source, as these heads a very expensive new. Chasers aren't cheap either, but if you're running production, they quickly pay for themselves. The die heads set-up basically the same as the driver, except when you reach the end of the stroke the die head keeps advancing a bit until it opens. You don't have to reverse the spindle, just retract the ram.
      Both of these operations are very quick.
      Harry

      Comment


      • #4
        Shop these guys first-http://www.sommatool.com/productslist.asp-(my old nemesis), and then buy from Ebay. Your turret has either 3/4 or 5/8 holes. You can use B&S '0' or "00" with adapters. If you're going to use tool holders, my suggestion is to make your own bushings.

        Comment


        • #5
          Hey Russ

          Does this little guy have some means of instantaneous reverse? A lot of these type machines did. It was either in the gear train or the setup of the motor. I know you’re thinking about swapping out the motor and depending on the availability of a means to mechanically reverse the spindle you may need to think about reversing the motor – especially for threading.

          On to threading:

          What I would do, because you know the limits of the machine, is buy a self-opening die head and a handful of chasers for the common threads you might be running. In this case you can cut your external threads and never worry about reversing your spindle. When properly set up, these will open when the thread has been cut allowing you to retract and index your next tool on the turret. You can either reset the die head manually or set a rod up somewhere so when you index the turret the rod will reset the tool. A 5/16” capacity head can be found for a reasonable cost, and say maybe a set of #10, 1/4, 5/16 chasers and you’d be set for a lot of jobs.





          As far as the tap holder goes, a floating tap holder is the best way to go there, it will have a bit of float axially (pushing and pulling on the tap), and radially (so it follows the hole if there is a bit of runout). You’ll need to reverse the spindle at the proper time though, that’s where the instantaneous reverse comes into play……. This one uses ER type collets to grab the shank of the tap. Older ones used a bushing over the shank with a setscrew and a square internal socket to grab the tang of the tap.



          Good luck

          Chandler

          Comment


          • #6
            I made my own compression type tap holder like Chandler described. Instead of a square, I milled a slot on center to engage two sides of the square. It works quite well.

            Two die heads came with my DSM but no useful chasers. They are quite expensive new so I haven't been able to use them yet. I suppose one could come up a home brew die holder. There are also the Acorn type die holders.
            Jon Bohlander
            My PM Blog

            Comment


            • #7
              Originally posted by IOWOLF
              Russ, you have a lot to learn about turrets.

              First they make a Tap head,and Die head for T/L's.

              What size holes in the turrets?

              Your Chamfer setup can be on any drill poss. This frees up a tool poss.,and that saves time/Money.
              Jay...that's putting it mildly...I have never seen one of these operate and am clueless.
              I've already dreamed up some hillbilly tooling for this but I'm sure I'd be reinventing the wheel..and poorly at that.
              EG...I "was" going to make a holder for a carbide insert to use in the cross slide for chamfering. I'm thinking you all would have another idea.
              The holes in the turret are 3/4". The new motor will have to be my instant reverse for tapping.
              Those die holders look pretty slick. I've seen them go for peanuts up here on fleabay but didn't know what they where.
              Ya, I've got a lot to learn. I'm learning that I have to work smarter. Short of a CNC machine or a big ol' turret setup, this little lathe will be mighty handy. And I'm not giving up on the hillbilly tooling...I'm pretty good at that
              I figure the guys here will help me cut down on the mistakes (Thanks Madman Mike)...as usual!
              Russ
              I have tools I don't even know I own...

              Comment


              • #8
                Harry, Rusty, Chandler and MM..Thanks for all the info! I'm going to take a bit to digest all this stuff while I fiddle with the machine to see how it all works.
                I have tools I don't even know I own...

                Comment


                • #9
                  Instant reverse not needed for tapping.

                  torker
                  You can find tap holders for turrets on ebay that are spring loaded and when
                  you reach the turret stop the turret stops and the tap pulls it's self out about 3 thds from holder then spins till you stop spindle. Then reverse spindle
                  and you can back tap out. Instant reverse not needed. See pic of one type
                  I own. Look at pic and see the area that shines behind the nut .That is how far it pulls out before the tap spins freely.
                  jims


                  Comment


                  • #10
                    Thanks Jim. Geez this is all cool stuff. Sure glad I bought this little lathe now. I was running out of things to buy
                    I have tools I don't even know I own...

                    Comment


                    • #11
                      Russ ,your best bet to locate the type of tooling you will need would be to get a Somma Tool Catalog. or check out the online Hardinge site. An older B&S tooling catalog will also give you much needed tooling information. As for drill chucks they are only as good as the alignment of the turret ,thus can be off center. you should get a set of adjustable drill holders instead. The older models by Boyer-Shultz, B&S and others used bushings to hold the drills and reamers. The newer style uses a pair of V-blocks and can hold from 1/16th" to 1/2" without bushings. A couple of floating reamer holders, balanced turning tools, box tools, adjustable boring tools, KNee tools, back rests and a rotating stock stop should be a good start. I would also try to get a copy of how to run a turret lathe by Warner -Swasey. your machine is a good little bar machinefor small jobs and second opperations work, but the principles of turret lathe work arte the same and are scalable. If I can ever get my photo bucket account to work from home I will try to post a few of the tools for reference.

                      Comment


                      • #12
                        ARFF79, thanks! I was wondering about a book but found waay too many on Ebay. Didn't have a clue which to buy.
                        About the drill chucks...I wondered about that. I'm thinking I may just make up an adapter for an old chuck I have and see how accurate the holes are compared to the spindle center.
                        The drill adapters..I guess you'd have to make one for every drill. Good project for the gurl when it gets slow.
                        I have tools I don't even know I own...

                        Comment


                        • #13
                          They also make 'Acorn" type threading tools for turret lathes as well. They work the same way a releasing tap holder works. Much simpler to set up than a die head. Another option for you.

                          Comment


                          • #14
                            Adjustable drill holders (vee type), releasing tap holder....

                            I have a couple of turret machines, those are the basic tools.

                            Stay away from drill chucks if possible, it's unlikely the turret holes are still exactly on center with an older machine, beside, you want as little overhang from the turret as possible for rigidity.

                            Hold off a bit on the external threading die heads. We run thousands of parts and the heads are not used near as frequently as the other tooling. Keep your eyes open and at some point you'll run across a deal on a die head with a large assortment of chasers. Until then, get the other tooling.

                            When you setup the machine you generally want "balanced" tooling. That term refers to having all the tool tips as close to the same extension from the turret. Keep that in mind when purchasing tooling. Your machine uses 3/4" shanks, some of that stuff can be fairly large, too much extension. On my 3/4" shank machine we use 5/8 shank tooling bushed to 3/4". That way we can minimize the extension from the turret. 5/8" tooling is usually relatively short in comparison to the 3/4" stuff.

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                            • #15
                              Good advice DR, Balancing tooling is good.But 3/4 is a bit odd I think, I was hoping for a 1".

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