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  • New lathe owner tooling recommendations

    Have just bought a DSG lathe with a standard 4 way tool post.
    Any advice on a good system to start putting together a quality/adaptable tool holding set.
    I might be looking at a quick change tool post in the future but for the moment need to utilise what iv'e got without wasting money.
    Absolutely no experience with different cutting bits/heads/tool types etc

    I would describe my expectations as cheap yet demanding.

    Al

  • #2
    Maybe add what size and type of materials you will be primarily turning.

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    • #3
      Go for inserted cutting tools, makes your life so much more easier despite them costing a bit more than a stick of HSS. Easier to get positive feedback from your work when you don't have to first learn how to make it cut.
      Amount of experience is in direct proportion to the value of broken equipment.

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      • #4
        With a 4 way post go you'll need shims ti place the children cutter on center
        Tom

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        • #5
          Insert cutters - the road to perdition

          Jaakko Fagerlund means well I'm sure and probably for a beginner who wants to get started quickly insert cutters might be the way to go, but ultimately you would be better off learning to grind your own cutters. I have taught a machine shop course for years to university students who have never even seen a lathe before and by the end of their first day they have ground a turning/facing tool perfectly and are cutting steel on the lathe. It really isn't that hard to learn the basics of grinding good cutting tools freehand. If you work exclusively with inserts you will become a slave to what is available commercially and when you need a specially ground shape you are going to be out of luck. Also, inserts are not "a bit more expensive" but ultimately WAY more expensive over time than starting with a tool blank and touching it up when needed rather than inserting a brand new cutting tip in an insert holder when the one you are using becomes dull or chipped.

          My suggestion would be to find a machine shop (or maybe a retired machinist) in your area and explain that you'd like to learn the principles of freehand lathe tool grinding. You might be surprised at the positive reception you would get to such a request. If you invest a six pack of beer into the bargain you might get an even better reception *LOL* Practice on keyway stock before going to lathe tool blanks to save a little money but even if you started with purchased, hardened, tool blanks the expense of a blank is not that much. Also, you can grind two cutters of different types (one on each end) of one blank.

          By learning to grind your own cutters you will 1) become a far more capable and versatile machinist, and 2) you will save a bundle of money over time.

          /

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          • #6
            The DSG has lots of mass and stiffness for dealing with any insert geometry. Even the negative rake rounded edge "plows" that are used on heavy machines for hogging off the bulk of the material.

            The trick is learning what inserts work for each material. And good luck with that. I'm a huge fan of HSS tooling but a few months back thought it was time to look into inserts. What I found was a highly confusing array of options with precious little data on what materials they are used on. The one thing I did learn is that you need to read the data on each insert for minimum and maximum cut depth. There's only a few where you can split a thou and get away with it.

            What we need is a thread on which inserts work well for what materials and how coarse or fine the cuts need to be. Like I mean where you can make a cut and when we back off the cutter doesn't take off .010 worth of spring cut. Or it's the wrong insert for the metal and the cutter is basically chewed to chowder in only a few passes. I know I've ran into both situations in my admittedly short and not so sweet trials of my own.

            Even if you do find a number of inserts that work for you I would still recommend keeping a few 1/2" or 5/8" HSS blanks around to allow you to grind up some form cutters for particular jobs.
            Chilliwack BC, Canada

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            • #7
              [QUOTE=BCRider;1081517] it.

              What we need is a thread on which inserts work well for what materials and how coarse or fine the cuts need to be. QUOTE]

              The problem with that is that the inserts available change every few months. The insert manufacturers change their lines fairly often trying to come up with something better.
              North Central Arkansas

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              • #8
                Answers so far are speaking to the turning tools or cutters to be held to the topslide. On that subject, I might suggest an inexpensively procured bunch of used tooling. Every machinist had his own and his decendents do not have any use and sell them cheap. Resharpening is easily done freehand and a bit of study will help instruct you.
                Just as important will be tailstock mounted tooling. You will need a good chuck and a selection of drills, reamers, and taps. A tailstock tapping and threading accessory is a luxury. You may want to make or buy a knurling tool. Holding a boring bar in the 4 way might be possible with a shop made v block and shims, but a real pain. I'd suggest looking at my article: Making a Boring Bar Toolholder Machinist Workshop Vol. 22 No. 1 Feb-Mar 2009 for an easy shop made boring tool holder. You probably will not need extended reach tool holders unless you intend to do crankshafts or something similar.
                In any case, enjoy your new friend.

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                • #9
                  [QUOTE=ulav8r;1081520]
                  Originally posted by BCRider View Post
                  it.

                  What we need is a thread on which inserts work well for what materials and how coarse or fine the cuts need to be. QUOTE]

                  The problem with that is that the inserts available change every few months. The insert manufacturers change their lines fairly often trying to come up with something better.
                  I'd settle for decent first hand information on even some of the basic inserts. Or what about at least the geometry of the inserts and what they work on really well? Adding in the weight and stiffness of the lathe they are used on wouldn't hurt either. That way anyone with lighter machines would know not to buy inserts that NEED the mass and stiffness of something like... oh.... a DS&G machine to work correctly. Not many of us have such machines.

                  Sorry if I'm coming across as a bit annoyed. But it's amazing how little the makers of these inserts have to give us about the answers to these questions that to me seem fairly basic.
                  Chilliwack BC, Canada

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                  • #10
                    Originally posted by BCRider View Post
                    Sorry if I'm coming across as a bit annoyed. But it's amazing how little the makers of these inserts have to give us about the answers to these questions that to me seem fairly basic.
                    The answers are out there, but you do have to dig around. The problem is that we aren't their target market. If you buy lots of inserts, they have technical people to advise you. They will come out, look at the parts, and suggest the inserts for each operation. I saw an interview with one of these techs, and he said that sometimes it's a bit of trial and error to find the best insert for a job. That's OK if you are going to run 50,000 parts over the next year, but not much good if you want to buy two packets of inserts for all your home shop needs.

                    Here's a simple way to get started with turning inserts. For a small machine, you don't want the second character to be an N (CNMG, WNMG, etc). The second character is the clearance angle, and N means no clearance (negative). Negative inserts are stronger and give you more edges per insert, but they also put more pressure on the part and the machine. They work great in a big machine though.

                    The first letter is the shape. Look at the shapes available. The closer they are to a circle, the stronger they are. The less like a circle, the easier they are to get into tight spaces. How many edges do you get from each shape? Can you turn and face without repositioning the tool? Which shapes are most available to you? Which holders can you buy for your sized lathe?

                    The other letters and numbers are less important for the home shop guy. Once you pick the first two, the available options drop substantially. For me (two-tonne, 18" lathe), most turning is with WNMG. Tough, six edges per insert, easy to buy. My big boring bars are WNMG as well, but that won't work on small boring bars (negative rake, big insert). So my smaller boring bars are CCMT. Seeing as I need to keep CCMT inserts for the boring bars, I bought a couple of CCMT turning holders for getting into tight spaces and for thin parts. CCMT is good for smaller machines, even small import machines.

                    WNMG doesn't get much love over at PM. Something about the pockets getting damaged when you push them hard. I think there was a preference for CNMG there. I'm obviously not trying hard enough because I haven't damaged mine yet If you are starting out with a big machine, then it's something to consider.

                    The other important consideration is the chipbreaker. These aren't standardised, so each manufacturer has their own. Some are simple, like FF for fine finishing and MR for medium roughing. Most home users don't need roughing inserts. Medium to finishing is all you need. Even a finishing insert will take a pretty deep cut. I haven't found any sharp inserts that compare to HSS. I know they exist because I was given a toolholder with one, but I haven't seen any for sale that are that sharp. This thing was sharp enough to easily cut you.

                    Comment


                    • #11
                      Assuming you already have 3 & 4 jaw chucks, a face plate, hard and soft centres, a revolving centre and a drill chuck or two for the tailstock.

                      Lots of useful bits you'll make to begin with benefit from a bit of knurling - get a clamp knurling tool, until you get into cut knurling clamp is the way to go as the forces are even on opposite sides of the work so you aren't pushing the work or the head bearings.

                      Get a tailstock die holder of the type with multiple sizes of interchangeable die holder, you're sure to want to quickly thread the end of a bar on a regular basis, buy good quality dies as you need them.

                      Beyond that buy the tooling required to do jobs as they come up, that way you can investigate the best thing for each application and save money in between purchases,

                      - Nick
                      If you benefit from the Dunning-Kruger Effect you may not even know it ;-)

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                      • #12
                        Just get a set of CCMT holders and inserts.

                        They work great on all steels, including interrupted cuts, and can easily turn out great finishes on hardened steels, drill rod, hardened bolts, cut ballscrews, all stainless, etc.
                        They last near-forever on alu.

                        I bought a 100 pack off ebay, about 2010.
                        In about 1000 hours of lathe use, I have about 50% still left.
                        Made maybe 200 pieces in steel, many are large like a 200 mm square block, 50 mm thick, in F1 tool steel, interrupted cut, face both ends and one face.
                        One piece like that holds the Z axis servo (ac, 750W) for my lathe.
                        Another holds the ISO30 spindle, for the VMC.
                        Both took about 8 hours to do (only can run about 80 rpm at ends of 200 mm workpiece).

                        Inserts cost maybe 100€ or so, for 100.
                        Total spend in 6+ years.

                        Most of my toolholders are 16 mm.
                        I bought most of my tools from chronos/glanze uk, way back with a minilathe, and they work fine on the 12" 2.5 kW lathe.
                        BXA size QCTP.

                        The CCMT inserts will cut 1 micron, incremental, in steel.
                        The tips do wear, but you are only doing a tiny bit of such cutting, and deeper cuts will still work fine.

                        My max cuts at 1.5 kW power were about 1.5 mm deep, 500 rpm +/-, steel, maybe 10 kg swarf removed, on a 250 mm iirc rounded washer.
                        Blue/black chips (sting and burn).
                        I would never use HSS if I can use an insert.

                        I will be trying WNMG, soonish, since I now have lots of torque from the new AC servo on the spindle.

                        Comment


                        • #13
                          I would second ccmt/ ccgt inserts and holders. Great for boring bars, a RH toolholder can both turn and face, a straight on holder can turn and chamfer, all using the same style of insert. Holders and inserts are seriously cheap if you don't mind import tools - I've paid around $5-8 per holder and $5-13 for a pack of 10 inserts. All 21.5* size, so the 31.5* size inserts and holders that would be more suitable for your lathe will be a bit more.

                          I have a really small lathe, but the ccmt do fine for roughing and interrupted cuts and the ccgt work beautifully in alu and for finishing cuts in steel. I've ground and used hss for several years with plenty of success, but these tools are both easier to use (turn face cut off with 2 tools and no moving the tool post) and give a way better finish.

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                          • #14
                            If you decide to grind your own tool bits get a book like the South Bend "How to Run a Lathe". It has the basic shapes and a lot of other information for starting out. If you grind your own, be sure to stone them until the grinding marks are gone when you look at the cutting edge with a 5 or 10 power loupe. They will cut better and last longer if you do.

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                            • #15
                              Good morning all. New here. Just a mostly dumb homemaker, inherited my Dads ancient worn south bend and now have a Grizzly 4003 with a QCTP, I have done a bit of tool grinding and do have scads of blanks and "custom ground" cutters. I do like the BXA QCTP on the 4003, the included 2 holders for the special grizzly inserts, not so much, not least of which to my uneducated mind these holder insert angles require a not 90 degree set up on the post which mostly defeats the premise? so I have been looking at WNMG (trigon) type inserts in 16mm holders. The 4003 QCTP will allow me to center 16mm holders and those holders feature a clamp as well as the central cam lock to hold the inserts.
                              So it seems like these would give me a lot of options for turning and facing work while keeping the post at 90 degrees. https://www.banggood.com/WWLNRL1616H..._warehouse=USA
                              Knowing nothing, 12mm holders without clamps let me cut down a motorcycle sprocket right through a series of lightening holes with no drama. Is there any reason for the "extra insert clamps" on a lathe like this run by an occasional user? Much of my expected usage is making aluminum axle and brake rotor spacers. Will need to get smarter faster on inserts but I am guessing I can find this same shape but with better relief for machining aluminum? Would also like to turn stainless steel motorcycle brake rotors which is probably a whole different kettle of fish. Anyhow thanks to any comments to my lengthy ramble.
                              Last edited by gggGary; 11-30-2017, 09:41 AM.

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