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Second-to-last Toolblock!

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  • Second-to-last Toolblock!

    Almost done- after this, I just have to finish up the TPG-insert facing toolblock.



    This one holds an 80-degree trapezoidal CNMG type insert. It's hard to see in this single pic- and was hard to cut as well- but the insert"splits the difference" in angle, so that it can both turn and face (the long axis is 45 degrees to the workpiece.)

    I also had to give it some negative rake, since they're zero-clearance inserts, and wasn't that fun to machine...

    I had to do a lot of creative guesswork, since I was cutting faces that were in no way, shape or form square, level or parallel to the block itself.

    However, in the end it came out well, though I took a shortcut and rather than using a center pin and a hold-down clamp, I just drilled and tapped it for a screw like on the threading insert block I made the other day. What the heck, the button head will sort of act like a chipbreaker.

    Once I finish the last block, I'll have twenty-one, total. That ought to be almost enough...

    Doc.
    Doc's Machine. (Probably not what you expect.)

  • #2
    Doc, Looks great but how's that fixed height working out for you? Den

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    • #3
      <font face="Verdana, Arial" size="2">Originally posted by Doc Nickel:

      Once I finish the last block, I'll have twenty-one, total. That ought to be almost enough...

      Doc.
      </font>
      Don't work like that Doc.
      When I made my first tool post I made 10 holders and found out I was about 3 short.
      When I made the second post [ different design ] I made 15 holders and found out I was 5 short.

      Now I have two identical posts on two machines sharing just over 50 holders and I'm about 10 short

      John S.

      .

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



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      • #4
        Very nice! You have most likely already noted this but I'll ask anyway. What are you using to blacken your equipment?
        Civil engineers build targets, Mechanical engineers build weapons.

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        • #5
          John, Maybe Marv K. can create a program which tells you how many you STILL need based on current number of machines and holders. It's such a shame to have to actually SHARE a holder between two tools
          Den

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          • #6
            Very nice work Doc! They are handy shape insert being able to turn & face without doing a tool change or turning the tool post and loosing your position. It's a pitty you don't get to use the other 4 points though. Maybe a couple more holders comming up?

            John.

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            • #7
              nheng- No complaints so far. I haven't used the "fixed" holders much since I started making them (just a few weeks ago) other than the parting tool.

              I did mean to ask though- are there situations where one might want a tool slightly high or slightly low? Especially a carbide insert which has it's own rake built in?

              Technically, the blocks can be adjusted. If I need it low, I can just undo the capscrew that holds the adjuster on, a few threads. If I need it high, I can put a shim under the stop.

              John- I started out with a single set (the five that come with a toolpost.) I then got a second post set for the other lathe, but since I don't use the first one as much, all ten holders kind of got defaulted to the main 11" machine. But then, of course, only the turner/facers really got used, and I still only had four.

              A few weeks back, I made six more, which helped a lot. I'm not having to switch actual tools in the holders nearly as much anymore.

              And with the (soon to be) five carbide-insert blocks, I'll have some dedicated to the common tasks like heavy stock removal (the CNMG insert) parting and threading.

              I do have a few ideas for some other specialized blocks, but at the moment those would be "just because I can" and not "because I need it".

              rockrat- It's called Gun Blue. It's a bottle of bluish... something, an acid of some sort, that you can get in most well-equipped gun shops or even in the sporting goods section of a K'Mart or Wal-Mart, if they have a reloading sort of section.

              Degrease the part thoroughly, then just dab it on with a cloth. The steel turns a deep blue-black instantly. After you're done, just oil and hand-buff. I've done all the blocks I made with it, in order for them to more or less match the factory blocks. Works well, seems to wear well. Easy to touch up if a corner wears white or it gets a scratch.

              nheng- You don't need a program for that. It's common knowledge that you will never have enough tools. Even if somebody handed you the keys to the entire Boeing plant, after they'd trucked in everything from the ENCO warehouse and MSC's facilities, you'd still get halfway into a project and find out you're short one key tool.

              zl1byz- True. I could make a flycutter type head to hold the inserts to use the shortside points... Though with the fun I had setting this one up for the compound-complex angles it took to make the pocket, trying to make three or four such pockets- and make 'em correct relative to each other- is not something I'm gonna want to take on at the moment.

              Doc.
              Doc's Machine. (Probably not what you expect.)

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              • #8
                Doc, I knew there were different tolerance grades but not how much difference ... the insert charts at carbide depot show 0.001" and 0.005" tolerances on thickness. A DCMT is 0.005" and a DCGT is 0.001" for example.

                Just found this:
                http://www.mmsonline.com/articles/0603cnc.html

                Den

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                • #9
                  Second to last one, not bloody likely. Lets see you need the scissors type knurling tool, the off set left hand facing tool, the reverse curve..........
                  Forty plus years and I still have ten toes, ten fingers and both eyes. I must be doing something right.

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                  • #10
                    DN
                    What grade of steel did you use for your tool blocks?
                    Charlie
                    Don\'t ask me to do a dam thing, I\'m retired.
                    http://home.earthlink.net/~kcprecision/

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