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what material to make something like this collet closer?

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  • what material to make something like this collet closer?

    In an earlier thread I asked for some details on a 3c collet adapter for a South Bend 9" lathe. Thanks to Mcruff for the drawing which provided all the details I needed and more.

    http://bbs.homeshopmachinist.net/showthread.php?t=29453

    Now, if I wanted to make such a collet closer, what material would or should I consider using?

    Would 12L14 be sufficient or would it be a bit soft? I don't have access to the facilities to harden and then finish grind and would add far too much $$$ to the cost of this project.

    How about 4140 (annealed) or 4340 (local supplier tells me this is their pre-hard 4140) or (suggestions) ?

    I will be starting with something about 1.75" diameter and will need to turn a 4mt taper on one end and then drill/bore/ream for the collet so there will be a fair amount of material that will need to machined away; so something that will not be too difficult to work is preferred - my lathe is simliar to the Grizzly 10x22.

    thanks,

    cheers, Graham in Ottawa

  • #2
    Pre-hard 4140 wears well (but 4340 is NOT it... that's different stuff). I've made arbors out of it. it's difficult to cut, wears the tool.

    But you CAN make it of anything... My father-in-law has a 9" and his factory closer does not seem to be particularly hard, judging from the dents it has acquired over the years..

    You won't wear it out in home usage, even of 12L14 and if you DID use it that much, it would be easy for you to make another.
    1601

    Keep eye on ball.
    Hashim Khan

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    • #3
      To save you a lot of time how about purchasing a "Soft" 4MT to 2MT sleeve (maybe 1MT as the 2MT maybe too large). Then you can machine the 3C dimensions in place.

      I did this last year in order to make 5C adaptor. In my case I used a worn out 5MT live center, ditched the parts and used the outer section. It was pretty hard especially the outer surface but some creative angle grinder work got through the skin so I could shorten the taper section to fit the 5C collet length. I was able to use the original front flange to hold it in the 3 jaw while facing it to length. You will have to do some creative thinking to hold a taper backwards.

      It turned out quite well and the front face turning and the subsequent boring of the internal taper worked fine with carbide tooling.

      Geoff

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      • #4
        Graham,

        I used 12L14 to make my 3C collet nose, and have been very pleased with it. Standard fare process to make it, indicated compound angle from spindle bore, turned 3MT, then installed and turned the ID and angle. I didn't actually have large enough material to make it properly, so I ended up threading on the face section, made from some 1.75 hex stock. it looks neat and functions just fine.
        Last edited by Walter; 06-12-2008, 11:45 AM.

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        • #5
          Originally posted by J Tiers
          Pre-hard 4140 wears well (but 4340 is NOT it... that's different stuff). I've made arbors out of it. it's difficult to cut, wears the tool.
          I've actually got some 4340 Pre Hard drops off Ebay. If you think 4140 PH is a bitch to machine...

          I'm a little dubious about making a collet closer out of 12L14. Leaded steel machines like butter, but you can dent it with a pencil (OK, a bit of an exaggeration ), and it rusts like nobody's business.
          "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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          • #6
            I agree with the idea of buying an inexpensive arbor. For the most part, the inexpensive imports are easy to machine. I have a 5mt spindle on my lathe and wanted to make an adapter to 3mt. I bought an import 5mt to 3mt sleeve with tang. I cut off the tang in my bandsaw and faced the end. It worked very well. You could easily machine the correct adapter in place and it would end up with very low tir. Make sure you mark the postion though... the imports are not perfect.

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            • #7
              Bruce, I would agree with that if he was trying to make an MT adapter, but can you even buy 3C sleeves anymore?

              Jerry, didn't you just publish an article in HSM in the last couple issues about making a 3C adapter of some sort?
              "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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              • #8
                Options?

                Graham,
                The collet closer for my 12" Atlas Craftsman is made simply from cutting down a #3MT adaptor, either to a #1 or #2MT inside. you don't really need the fancy flange, although I guess it gives some protection for the spindle face. Just make sure that the through hole at the back will allow the collet easy passage.

                These come in soft+ hardened tang or case-hardened varieties, with the soft being cheaper-$9? .

                I recently changed the entry angle on mine to the 12 degrees, and from this light machining, it's obviously the soft version, and has held up perfectly since the early fifties.
                Richard in Los Angeles
                Edit/Delete Message

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                • #9
                  Lazlo:

                  JT did the article on the 3C collet block, a hex shape IIRC.
                  I bury my work

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                  • #10
                    All good advice, thanks.

                    I usually tend to fall back to KISS but before I overthink something before I get there.

                    Using a 4mt blank end arbor has always been one of my options. My only concern is how hard they really are. For example, I want as little overhang as possible so that would mean cutting the arbor back close to the spindle - the end is soft but would I be able to face the arbor if I cut it well back from the soft end? I know the other end is reasonably soft as well. I have cut the back end of with a cutoff wheel and faced off, and drilled and tapped for drawbar on several all ready. I am no stranger to the blank end arbors as I use them frequently to make specialized too holders.

                    So, I guess the question really is (and one to which I don't have a very clear answer) are these blank or soft end arbors really case or flame hardened where they are not supposed to be soft leaving the insides relatively soft or are they hard all through? I suppose the answer is "It depends, on the source and manufacturer".

                    I don't have any 4mt blank end arbor to hand and seeing as that is the direction I am leaning to at the moment perhaps I should just get a couple and "just do it".

                    cheers, Graham

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                    • #11
                      Lazlo-
                      My suggestion was to buy an adapter that fit in his spindle and machine out the 3C in situ. He might also have to cut off a tang and face that end as well.

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                      • #12
                        It is actually rather easy to make a morse taper, and good practice..... If you use your compound to get the angle it can take a bit of tapping to get alined, but you can make a couple extra blamks for MT things while you are at it.

                        And, it's dead easy when you are alining to the taper in your spindle... it's right there for reference.

                        There is so much work to do to an adapter to get it to be what you want, that it hardly seems any easier than a 'from raw stock" part. You need to cut off and face the thin end, and you may want to cobble up a temporary drawbar to use for holding it while you machine the inside, which isn't easy if you don't have extra material there otehr than the tang......

                        Not to mention that you will not have material available to form the portion that the nose protector uses to eject it from the taper.... You'll want that, because it WILL get nice and tight in the spindle.
                        1601

                        Keep eye on ball.
                        Hashim Khan

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