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5c step collet doofer

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  • 5c step collet doofer

    http://www.ebay.co.uk/itm/Hardinge-t...item564543f3ca

    are you suposed to put your own steps in this ..and face off once you have a load of steps you dont use .

    are they any good ?

    all the best.markj

  • #2
    never heard it called a STEP collet. It's a machinable collet. You bore
    whatever you need in it and then re-machine to the next requirement
    when that occurs. We have half a doz with all sorts of weird things
    cut in them. :-) You do have to put spacers in the slits while machining.
    ...lew...

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    • #3
      I have seen some pre-machined step collets (over sized collets with recesses for several different sized objects, bars etc,) but not for the 5C. You could make one out of those blanks.



      Woo hoo 2000 posts.
      The shortest distance between two points is a circle of infinite diameter.

      Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/

      Southwestern Ontario. Canada

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      • #4
        Yes, step collets are the ones which exceed the capacity of the collet body. They need a "closer" to work. This is a funnel-looking spindle nose cap. As you draw back the collet, the closer provides the taper to close the collet. The one you link to is a soft faced collet you bore to the size you need. It is not really meant to machine a ton of steps... i.e. sequential diameters for holding various diameters on one collet. I guess you could, but I've never really seen anyone do that with a soft face collet. Some makers offer hardened, finished collets that are like that. You can also find hardened, finished to size step collets. For example, 5C is available in larger sizes such as 2". You need the closer to use them, remember.
        Last edited by Arthur.Marks; 12-31-2011, 11:28 AM.

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        • #5
          Originally posted by Lew Hartswick
          never heard it called a STEP collet. It's a machinable collet.
          that's what I've always call them. Also pot collets (as I found out googling this wondering if I'd be calling them the wrong thing all this time)

          http://www.royalprod.com/product.cfm?catID=6&id=39

          I've got a bunch, they do what they're supposed to do. You end up over time machining a set of ever small dia or steps. Presumably if they're not all oddball sizes, the collet just becomes part you tooling. In watch makers sizes the steps are already there, can't recall if I've seen a 5C step with the steps pre machined
          in Toronto Ontario - where are you?

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          • #6
            5C "step" (or "clutch") collets come in a couple of different flavors - the one pictured seems to be the type that uses a taper external to the outside of the collet face (Hardinge type), there is another that uses the standard collet taper for closing. The one that uses the outside of the face has a much stronger grip than the other, but sometimes even a loose grip is OK.

            For the Hardinge type they make closers in 2" to 6", the max taper in the holder is usually .375" above the nominal size. Hardinge holders are made to their spindles - 2 3/16-10 threaded and Hardinge Taper; I've also seen closers with D1-3 backs. When I needed one I made a threaded spindle adaptor for my D1-3 spindle, here it is with a 5" closer in it:



            If you look at the face of the collet you can see small holes in the slots, these accept 1/8" pins and are used to keep the collet from closing when machining. Most machinable collets have something of this sort to allow you to hold the collet and machine things to accept the work.

            On edit: I usually start with a small diameter on the machinable collet and open it out as I encounter larger work. You can often find these collets on eBay but many are machined out as far as they're going to work and are only useful for that diameter or as steel scrap. Ones that have just a small hole in them (relative to their OD) have a lot of life left in them.
            Last edited by rkepler; 12-31-2011, 11:43 AM.

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            • #7
              so you're saying the draw bar will not work with this type of 5c collet

              all the best..markj

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              • #8
                No; the drawbar is still needed to draw the collet back into the spindle to engage the taper on the closer. The drawbar does not change in either length or purpose.

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                • #9
                  The larger size of these step chucks are fairly expensive. The one linked to is a bargain.

                  I've taken to welding new inserts into some to salvage a used up collet (Hardinge does not recommend that, I asked).

                  The Hardinge collet book (is it still in print?) showed a simple way to modify these type step chucks and closers to be dead length. "Dead length" meaning no pull back of part as the collet closes in case you didn't know.

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                  • #10
                    Originally posted by Arthur.Marks
                    No; the drawbar is still needed to draw the collet back into the spindle to engage the taper on the closer. The drawbar does not change in either length or purpose.
                    i dont understand what you are saying ..did you think i was going to buy one of these collets without any sort of closer

                    my lathe has built in 5c collet spindle ..in the middle of the spindle bore which is d1/4 camlock mount...as you tighten the draw bar it pulls in the collet which grips the work

                    but you all seem to be hinting that i should have some other part called a closer .

                    all the best.markj

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                    • #11
                      There are two types of the larger sized pot or step collets. One requires a separate closer, one does not. It is difficult to determine whether the pot collet in the eBay link requires a separate closer or not, but I doubt that it does. What appears to be an angle on the OD, I suspect to be an effect of the photo. It would probably be best to contact the seller.

                      One thing that I do notice in the photo is the lack of the pins that hold the collet "open" when machining the step. They are not missing, there appears to be no provision for them at all. This might account, in part, for the low price.
                      Jim H.

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                      • #12
                        I've got a few of the pot collets that use only one pin in the center for clamping while machining the pot.
                        You need a picture of the backside of the collet to see if it has the 5-C taper. If not , then you need the separate closer for the OD.
                        These collets do come in handy.
                        Harry

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                        • #13
                          The company I retired out of we used the hardened and ground ones a lot. Hardinge and very pricey. But worth it from a time savings viewpoint. As said they require a closing ring especially above 1-1/4 IIRC. The closers themselves are fairly soft so they need to be handled with care both in mounting and use. Also these come in two different lengths. 3/4 and 1-1/4 deep. I'm not sure if the closers will work with both lengths as they make both lengths. Plus remember these project outside of the normal spindle nose. Plus for soft ones you can make your own.
                          Forty plus years and I still have ten toes, ten fingers and both eyes. I must be doing something right.

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                          • #14
                            Originally posted by aboard_epsilon
                            my lathe has built in 5c collet spindle ..in the middle of the spindle bore which is d1/4 camlock mount...as you tighten the draw bar it pulls in the collet which grips the work

                            but you all seem to be hinting that i should have some other part called a closer
                            It depends on the collet. Here is a pic of the 2 different kinds we're talking about (ignore the anti-rust goop, I wasn't going to clean it off in a cold shop):



                            The one of the left is the 'standard' taper 5C shank, where the taper for closing the collet is on the shank of the collet. On the right is a Hardinge step collet where the shank doesn't have a taper but instead the taper is around the face of the collet. The first type will close in a standard 5C closer, the latter needs an adapter. The difference is that the first will not close as tightly as the second on large diameter stock - if that matters you'll want the type requiring an adapter.

                            (There is a hybrid type with tapers in both places - and they work relative to the taper that you tighten on.)

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                            • #15
                              Originally posted by rkepler
                              It depends on the collet. Here is a pic of the 2 different kinds we're talking about (ignore the anti-rust goop, I wasn't going to clean it off in a cold shop):



                              The one of the left is the 'standard' taper 5C shank, where the taper for closing the collet is on the shank of the collet. On the right is a Hardinge step collet where the shank doesn't have a taper but instead the taper is around the face of the collet. The first type will close in a standard 5C closer, the latter needs an adapter. The difference is that the first will not close as tightly as the second on large diameter stock - if that matters you'll want the type requiring an adapter.

                              (There is a hybrid type with tapers in both places - and they work relative to the taper that you tighten on.)
                              Aha ..i see

                              the listing was for a 5c though ..so it dont need a closer ..right.

                              all the best.markj

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