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  • fdew
    replied
    I have been following this carfully. I need a cutoff tool (Ihave been using a home ground HSS 1/2 tool bit.) My lathe came with a Aloris holder AXA7 that is designed for T shaped cut off blades. I am going to start with that, knowing that some day I will want to move up to a carbide system. My question,

    What assortment of widths do I get? I can go from .040 to 1/8 I am liiking at the Enco USA blades.

    I will be cutting cast iron and steel up to 2 in thick

    Thanks

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  • ACF
    replied
    Lazlo,

    As well as those carbide parting tools work, that blade you have there with the 8 inserts, ought to be one badass metal moving monster!!!!

    Chris

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  • lazlo
    replied
    I think I'm dangerously over my "Piss off Norm" limit this week , but I have to agree with BadDog, Peter et al: I have the Sandvik parting tool system, and it's fantastic. I think the reason it works so well is because the nose is shaped like a chute that flares outwards: it curls the chip away and up from the workpiece, minimizing the cutting forces.

    Like Norm describes, Geo Thomas shows some fancy cutting tip geometries to minimize parting forces, but there's no way a home-shop guy could make the curved 3D nose shape on the Sandvik, Newcomer, et al parting tips.

    Now, along those same lines, Sandvik also has a very cool slitting/slotting saw that uses the same inserts: basically picture 8 of the parting inserts mounted radially on a milling arbor. I just got this in last weekend, and I've been cleaning the Excello since, but I'm dying to try this on some 4140 Pre Hard:

    Leave a comment:


  • Spindle
    replied
    Click that enco link, the resulting page will have a link to Master Catalog page 188, blade cutting depths are on a chart at the bottom of that page.

    Leave a comment:


  • Dave P.
    replied
    Originally posted by Bill Pace
    I chose the one already mentioned, from ENCO, the Newcomer. With getting the kit, you'll get everything ready to use with your new QCTP including 10 of the inserts. Get one that takes the narrow inserts, it is much easier on your lathe -- in the Newcomer its .087. Heres the one I chose ---
    http://www.use-enco.com/CGI/INSRIT?PMAKA=422-2914

    As mentioned, its qualifies for free frt, too --- use code PRPT12 (that'll expire end of the month...)
    Going back in time a few days.....
    Bill,
    What's the max reach with that setup?
    Thanks
    Dave P.

    Leave a comment:


  • Spindle
    replied
    Weeeeeeeeeeeeeell that clears that up..... But seriously- it seems like the HSS and carbides have their respective advantages and disadvantages. Plenty of reasons to have both.
    I'll be back with many more questions.

    Leave a comment:


  • tornitore45
    replied
    Thanks Norman, much clear now.
    Exaggerating the idea, the tool act as a scoop.
    I am using now a T blade on a home made rear post with no agle because it has no height adjustment to compensate for different protrusions.

    Even witgh a simple flat tip, zero rake, it works well on my Chinese 9x20 but I am always open to improvement particularly if this is a old technique validated by time.

    Agree, drawing is the language of geometry, words are a poor tool for shapes.

    Mauro
    In Austin TX

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  • Guest's Avatar
    Guest replied
    Part off Blades

    I would agree that it is difficult to comprehend. Bit like being avalanched and having to spit!

    OK- lets do the blade itself.
    Along the top of the blade( about an inch) is a female vee of 140 degrees or a curve( from a worn slitting wheel) Female is female- going into as in a con-cave.
    The front of the tool has a male chamfer of 140 degrees- male to go out and into over or when one is vexed- you go out. ( Sounds a bit but that's the way of the World)

    The tool is inclined at 7 degrees to the work( at centre height)
    If you think- you don't need to put a back rake on the tool because it is inclined. So all that a re-grind needs is a tiny bit of grinding off at the front.
    Actually, it is simply a normal cutting tool. You could use a flat topped lathe tool in the rear tool post- instead of grinding back rake.

    I hope that that is clearer.

    Why not E-mail me at [email protected]
    In truth, it is easier to draw than write about.

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  • tornitore45
    replied
    Originally posted by Norman Atkinson
    We've been through all this before and before.

    The classic answer is to use a rear tool post and run the lathe forwards but using a tool inverted at a 7 degree slope. Set at exact tool height, of course.

    The top of tool remains straight but has a convex grind along it. The recommended grind is a vee of 140 dgrees but I found a simple curved female grind( calm down, fellas) was enough. The front of the tool had a male 140 degree vee'd edge.

    Norman
    Norman, let me see if I understand you description.

    7 degree slope mens that the bottom surface of the inverted toll present a positive 7 degrees rake, right?

    The word convex and female puzzle me. W are still talking about the bottom surface of the tool. Convex, to me, means that the V looks like a house roof not a V groove. Female, means (i think) hollow in the center, in this case a groove or a arched though ground lenghtwise. Right?

    As for the tool front I understand a male V to resemble the stern of a ship.

    Please clarify thanks

    Mauro
    In Austin TX

    Leave a comment:


  • Guest's Avatar
    Guest replied
    Part off Blades

    The subject WAS a 5/8th Parting tool blade held by somebody who found it necessary to fling the whole lot into the (Roman) Forum to be torn to bits
    ( Well metaphors and whatsits permitted) The blade was HSS and not carbide and unusually for me, I kept to the question( at the beginning, anyway)
    <Wait for roar from the Plebians>

    Now Peter, I could have been naughty and got unfrocked or worse for suggesting that he could have made a tool and cutter grinder from plastic( err uhm). Instead, I gave a thoroughly good economics argument of what in the year of our Lord 2009 what the economic choices were- TWO parting off tools ( Minus holder) and an all singing whatsit which would sharpen every tool in the armoury until the end of time. It was more or less conditional that the guy would accept HSS ( which he had).

    OK - Peter, you remind me of Huskisson- no, that was a train but that, if my economic history class continued next week would go to Brighton- and Red Flags abandonned.( that's the history- fellas- of Reckless Speed)

    So £50 eh? for all those poor, starving children! Peter, my friend, I could have got 19(yes) courses at the start of the Year of the Ox for £16 a head- of which £1 went to buy Teddies for Kids in Hospital.



    Right off topic-- Kung Hei Fat Choy! But it does wish you all a happy(chinese) new year.

    Ling_Sam Sam Yee_Say-Say

    Norm

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  • Peter N
    replied
    Ah but but we weren't talking about Tool & Cutter grinders Norm, I think the discussion was more along the lines of parting off blades

    Of course these days £50 is nothing really, about what I spend on a Chinese takeaway for the family, and with the same carbide insert having been in there for about a year or more now, even more of a bargain.
    You don't have to be sad and sorry all in one post Norm, and despite the cost of flags in China you can't accuse them of being guilty of neo-Luddism

    Peter

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  • 3t-
    replied
    dockrat,

    Thanks for the photo, that is the blade I have been using but had not ground the radius as you have so I'll give this a try. Also just set up my new QCTP, 100 series, so I will utilize the parting tool holder that came with the set. Does the angle that your tool holder presents the blade to the work impact + or - using that QCTP configuration? I see that rear tool post as interesting and a nice project with practical use but it will not fit to my Atlas so will save it for a future lathe.

    Leave a comment:


  • Guest's Avatar
    Guest replied
    Part off Blades

    Peter,
    Sadly these new fangled gadgets come at HALF the price of a 2nd Hand professional tool and cutter grinder. I bought a Clarkson for £100.
    Again, I was offered an unusual Stent which was fabricated for the same- with a heap of accessories.

    I was in HongKong and have connections there. Red Flags still cost money there.

    The Chinese 'Luck Money' is due by the 12th- want a coin?

    Sorry, but I am living and succeding in this weird economic climate.
    When I went to college- one grossed up £50 as it was paid out of net and therefore taxed income( at 40%) Hasn't changed much- it was 50% then

    Regards

    Norman

    Leave a comment:


  • Peter N
    replied
    Years ago they used to have a man with a red flag walking in front of cars to warn people of the vehicle approaching and avoid accidents.
    It worked very well, but then they had to go and make progress using more modern technology and found a better way to do things Dammit $*!!

    Of course, some still maintain that this was the only way to do it, and the idea should not have been forgotten, others just shrug and use the new stuff which is easier, quicker, and doesn't need the additional burden of a man in front.

    Bit like parting tools really. Rear parting toolposts still work well, but a modern approach like this : http://www.greenwood-tools.co.uk/shopscr23.html works even better, even on speed and rigidity-challenged small lathes like the Myford.
    I've used mine on the Myford and Colchester on everything thing from small stainless and sliver steel bars to a 2" lump on EN19T, and I would never go back .

    Peter

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  • Guest's Avatar
    Guest replied
    Part off Blades

    Parting off? Well, not really!

    I thought that if I was still a bit - crook as they say in OZ, it would make sense to pass along a few more hints from 'goggling' -sorry 'Googling'

    Have a go at 'GadgetBuilder.com'. Understandably, there is a lot of stuff which appears elsewhere. Nevertheless, it is better to a bit of duplication than nothing at all.

    Whilst you are in Googling mood, there is an old site- out of date and perhaps, you will not be able to get all of it. However, try 'Chris Heapy'
    A Japanese modeller sort of resurrected it and newcomers will really enjoy the wealth of information.

    Tell me, tell us of whether you have found both sites useful.

    Meantime, more eyedrops and a rest up.

    Cheers
    Norman

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