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  1. #16
    Join Date
    Nov 2017
    Location
    Geelong, Australia
    Age
    57
    Posts
    2,651

    Default Cutting tool question

    I'd advise against going down the QCTP route for a start. Don't get me wrong - I have one and love it, but the standard set of holders that you get with the QCTP is actually less flexible than your 4-way post.

    I'm with Masterspoon - grab some cheap CCMT insert holders and inserts and just have at it!! Only buy the smallest boring bar that will take the same inserts. Don't bother with any larger ones for a start - you just won't use them.

    Metal pallet strapping makes good shims for tool holders. Use a thick bit of flat stock to get as close as you can to center height and then insert a couple of short bits of the strapping to pack it up to height. When you remove that tool holder - put it somewhere with its shims/packers so you can just grab the whole lot and bang it in next time.

    Buy a couple of pieces of decent 6mm or 1/4" HSS, and a white grinding wheel as Morrisman suggested.
    Kryn suggested practicing your grinding on square bar. If you do that I'd suggest getting a bit of key steel from a bearing or industrial supplies place. Its nice and square and grinds well. DON'T USE YOUR NICE NEW WHITE WHEEL to grind it. Only grind HSS on that wheel.

    For one of your first projects - get some square stock the same size as the toolholders you buy and about 30mm longer than the slot in your tool post. Drill a hole straight in the center of one end that is big enough so you can just slip the square HSS in. Drill and tap a hole from the top to fit a bolt or grub screw that will screw down on the HSS and clamp it.
    You now have a nice simple toolholder for your HSS. If you bought 2 pieces of HSS you have 4 ends to turn into tools.
    This one is round - but will give you the idea.



    Yes you could just clamp the HSS directly in the tool holder, but in my experience its "slippery" and doesn't clamp well, and the tool tip ends up quite close to the tool post and limits where it can get into.

    Steve

  2. #17
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,439

    Default

    Hi Vic, Guys,

    If you have a scrap yard anywhere near, you may find that they have bucket loads of HSS tool steel kicking about. Almost all the HSS that I have came from my local scrap yard. You should be able to buy it for next to nothing.

    Some one made a comment about honing HSS lathe tools. Ideally a fine carborundum slip stone would be used for this job ! My tip here is to get a sheet of fine, say 600 or 800 grit wet and dry paper. Cut a strip of hardwood say 12 to 18 mm wide and glue a strip of abrasive paper to it, then use it like a fine file on the top face of your lathe tool.

    A similar stick with say 80 grit is useful for deburring an edge whilst its turning in the lathe chuck.
    Best Regards:
    Baron J.

  3. #18
    Join Date
    Mar 2011
    Location
    Southern Flinders Ranges
    Posts
    1,536

    Default

    Your situation is one where, like most of us here, you’ll end up using tool steel for some jobs, and carbide for others.
    I’ve had a lathe in my shed since the early 00’s and I’m yet to buy a quick change set up (contemplated it seriously last year, then got an 18K bill from the ATO).. although I am at the point I probably will buy one next time I go to Melbourne.

    Do you need a quick change initially, I would say not. Scraps of sheet, flat, bandit strap and a set of cheap feeler gauges to cut up will get you on the money. I found this helped bring a degree of accuracy into my use of the machine, as frustrating as it got at times when first starting out. You can put multiple tools into a four way at once.

    My personal experience was starting out with tool steel because that’s what I remembered from high school tech and basic trade inductions (my trade is not machining or toolmaking for reference). For me this was a good way to learn the machines I’ve had. Tool steel requires slower speeds and feeds than carbide. I also found tool steel more forgiving, if you dull it, it’s just a case of take it to the grinder, knocking edges off carbide inadvertently costs you money. When you put your big boy pants on and actually start using carbide to its fullest it is a very intimidating scenario. Spinning the chuck three times faster and running three to four times the depth of cut is scary the first few times you do it if you are not used to it.

    Ultimately, as I said earlier, you will almost certainly wind up with both HSS and Carbide tooling in your tool box, so it’s really just a case of which set of principles do you want to learn first.

    Best of luck.

  4. #19
    Join Date
    Jul 2008
    Location
    near Warragul, Victoria
    Posts
    3,718

    Default grinding

    This might be helpful https://www.georgiagrindingwheel.com...els_basics.htm

    I use the normal periphery of the wheel for shaping the blank , I use the wheel sides for the final light touch up. I've heard of serious accidents where these wheels can explode when they are treated roughly. I always use a full face welding helmet when grinding HSS tools with the dark shade lens lifted up.

  5. #20
    Join Date
    Apr 2020
    Location
    Ettalong Beach NSW
    Age
    62
    Posts
    72

    Default

    Fantastic support! Thanks everyone for your generosity and information. I have enough to go on now.
    I'll stick to the 4 way, make my own holders and you have given me enough confidence to have a crack at grinding my own tools.
    I'll start with the HSS and graduate to Carbon inserts second.
    Cheers all.

  6. #21
    Join Date
    Jun 2011
    Location
    gold coast
    Posts
    303

    Default

    HI Vic, ..
    I started several years ago in your boat too, with the same questions.
    If I had my time over again as a hobby machinist, I would buy ONE diamond toolholder (RH)--(not the pair) and the sharpening jig, and the eccentric engineering inverted parting tool. You can decide on using HSS toolbits or lash out for a Crobalt tool bit--which eccentric engineering also sell.

    This setup will fit your 4 position toolpost, and height adjustment is done easily by loosening the clamping screw that holds the tool bit (diamond toolholder) and moving it up and down by hand then reclamping---a few seconds work. (no shims required)
    Stick a toolbit in the sharpening jig and apply to any HSS sharpening wheel---no skill required to sharpen or touch up.

    The parting tool parts in reverse, and is less 'stressful' for a smaller lathe.

    This will get you started machining and parting off . That should keep you amused for 6 months

    For boring---you can have the fun of making some boring bars, or buying a simple 8 mm or 10mm one from 'overseas'.
    There are some 'fun' ones you can make using broken drill bits as cutters. Just add a grub screw and you are in business! (tongue in cheek)

    Good luck
    Brian

  7. #22
    Join Date
    Jan 2004
    Location
    Mackay North Qld
    Posts
    6,446

    Default

    Quote Originally Posted by Vicval01 View Post
    I feel like a thickhead, but I just have to ask this question.
    As a new inductee into the mysteries of lathe operation, having acquired a Sheraton without any tooling, I do have a 4 way tool post.

    Do I buy a HSS pre-shaped cutting tool kit and then shim the various bits as needed to get the right height, or do some people use tool holders that go in the post which are mounted at the right height, avoiding the need for shims?

    OR, do I invest in a quick change tool post and a handful of adjustable holders?

    If I were to choose the QCTP, how do I work out what will fit my specific lathe? (Sheraton Conquest 10 A)

    (I don't think I'm ready to buy blanks and grind them myself.)
    Thanks.
    Get used to your lathe, and work out what you actually do with it before you spend a bunch of $ on tools that don't actually work for the jobs you do.

    I would go with the HSS tools first. There's bound to be someone around who could sharpen up a beginners set of blank HSS tools for you. Once the basic angles are ground it not hard to re sharpen them.

    HSS tooling will give you a pretty sound basis in the edge needed for different types of work, and the bits are cheap, and easy to reshape, resharpen, and make them work to do what you need them to do. When you want to fit a circlip it is so easy to grind HSS to the clip groove size. If you can do that with a carbide tool,I am not aware of it.

    As for making your own HSS tool holder,why not? I can't remember the vertical width dimension on my 4 way tpost, but it would not be too hard to make up a tool hoder to fit your t /post using some cold rolled steel ( whatever size fits the aperture.I have done the same for my QCTP blocks and fitted them with 16mm square cold rolled ,drilled to take the HSS.

    Carbide tooling is not a cure all and it can be an expensive learning curve, as you learn to not bump the cutter edges against the work when it is not rotating (chipped inserts, often enough). I am not saying you will never have the need or use a carbide but having done your apprenticeship HSS you will know when and where carbide is warranted.

    You can use your 4way toolpost but shimming every time gets to be a pita real fast. A good way to save time is to make a shim stack and tape them together.

    Another "trick" was to use thicker metal pieces of 6mm and 3mm to get height and finish off with a few thin shims to get correct center height.

    As for the tangential tool bits they have merit too,but you still have to have a separate part off tool and possibly a knurl tool.

    The positive side of learning to grind HSS is that it seems easier to then go on and try drill sharpening by hand. I grind my battery drill and drill press drills by hand but have another new set for accurate use on the lathe only.

    Grahame

  8. #23
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,439

    Default

    Hi Guys,

    Quote Originally Posted by Briangoldcoast View Post
    and the eccentric engineering inverted parting tool.
    Let me correct this statement !

    The parting tool parts in reverse,

    The lathe does not run in reverse ! The parting tool blade is mounted up side down, behind the work at the back of the cross slide !

    This will get you started machining and parting off .
    For boring---you can have the fun of making some boring bars, or buying a simple 8 mm or 10mm one from 'overseas'.
    There are some 'fun' ones you can make using broken drill bits as cutters. Just add a grub screw and you are in business! (tongue in cheek)

    Good luck
    Brian
    Best Regards:
    Baron J.

  9. #24
    Join Date
    Jun 2007
    Location
    sydney ( st marys )
    Age
    64
    Posts
    4,887

    Default

    Indexable carbide can be ground to suit different applications if required, reducing nose radius, thinking grooving tips for recesses etc.

  10. #25
    Join Date
    Aug 2008
    Location
    Melbourne
    Age
    34
    Posts
    1,075

    Default

    I don't believe there is any application or process that doesn't have a carbide insert available for it (Guhring makes grooving inserts down to 0.5mm and boring bars to 0.7mm ), but then you need to invest in holders and it gets expensive.

    Definitely worth learning how to grind HSS for stuff like that and if you can do that you can fiddle with carbide too, you just need a diamond or CBN wheel.

  11. #26
    Join Date
    Apr 2020
    Location
    Ettalong Beach NSW
    Age
    62
    Posts
    72

    Default

    I'm getting closer to starting the first round of purchase. A couple of questions: What size tool holder is appropriate for my tool holder? It looks as if it will accommodate around 20mm shaft. Is bigger better? And what size hss steel? Again, is bigger better?

  12. #27
    Join Date
    Apr 2012
    Location
    Healesville
    Posts
    2,129

    Default

    Quote Originally Posted by Vicval01 View Post
    I'm getting closer to starting the first round of purchase. A couple of questions: What size tool holder is appropriate for my tool holder? It looks as if it will accommodate around 20mm shaft. Is bigger better? And what size hss steel? Again, is bigger better?
    To get your tool height measure from the bottom face of your tool post, from where the tool holder sits to your tailstock centre.
    Dont get a tool height higher than that or you will have machine the bottom of the tool holder to bring the tool height down to centre.

  13. #28
    Join Date
    Jun 2007
    Location
    sydney ( st marys )
    Age
    64
    Posts
    4,887

    Default

    You don't want to go the full width of your pocket, you won't be able to adjust height.

    In my opinion if you are not going to buy or make holders to hold your HSS, use 12 mm, 10 mm and 6mm HSS pieces 100 to 150 mm long for external turning.

    For internal boring use 3 to 6 mm square or round HSS and make a boring bar to suit , as has been mentioned earlier.

  14. #29
    Join Date
    Aug 2008
    Location
    Melbourne
    Age
    34
    Posts
    1,075

    Default

    Bigger tool holder means more rigidity; this is always good if it doesn't end up too high (fixed post means you can't bring a large holder down, only a small one up). The distance from the bottom of the tool post pocket to the centre of the spindle is the target to aim for when buying holders for carbide.

    For HSS, 3/8" and 1/2" square should do for most things; bigger is still better (rigidity and all that), but it means you have to grind more to make a tool.

    Another note when grinding HSS; don't worry if you blue the edge a bit, it's cosmetic only.

    EDIT: looks like a bunch of us were typing at once, +1 for the above responses as well

  15. #30
    Join Date
    Jun 2011
    Location
    gold coast
    Posts
    303

    Default

    Baron J,
    You are right!
    But so am I.
    The eccentric Parrting tool is installed in the toolpost upside down (in the front of the lathe) and the lathe is run in reverse.
    Not that its important--apologies for being pedantic
    warm regards
    Brian

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