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Tell me about collets please

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  • #16
    If your lathe is native 5MT spindle taper, then you can almost any of the most common collets, with proper adapter.
    Yes, collets, any collets, are by far more accurate than any scroll chuck.
    I'll try to give Brian a quick description for collets, their use, as he would buy them, please refrain from all the inside shop tricks, gizmos, and collet doo-dads.

    MT collets close by using a drawbar, which negates using long stock thru the spindle

    5C collets are the most common lathe type collet, they are threaded both inside & outside.
    5C outside threads are for the 'drawbar' or nut, to pull the collet closed ,but, this 5C drawbar is hollow and does allow for long stock in the spindle. (referred to as drawtube)
    5C inside threads are for a stop block feature that gives you a depth stop for repetitive depth or lengths.
    regular 5C collets accept up to 1 1/16" diameter stock, and all sizes from about 1/16 up to max and everything in between, metric, SAE, whatever.
    5C pot collet lets you hold stock larger than 1 1/16 but does not pass thru inside, it holds larger stock like holding onto your fingertips.
    there is 5C collets to hold square, hex, stock in various sizes
    5C emergency collet is a blank collet, soft material, you turn the ID to suit your custom need at the time.
    Emergency collet should be of interest in little crankshafts & cams because you can make a eccentric with it.
    All 5C I have just mentioned are available to order off the shelf.
    Other guys get fancy & tricky and do even more stuff. I'm only saying what can be had common mail order stuff.
    There is a adapter for 5MT-5C. here is but one example
    https://www.ebay.com/itm/5C-Collet-L...kAAOSwFnxaeNUA
    5C collet blocks have a nut that pulls the collet closed, they are very handy as you can move parts back and forth from lathe to mill and stay in the same collet.
    you can hold a collet block in a lathe chuck and turn with it, or vice versa hold it in mill vise.


    ER collets close by the nut threaded on the nose of it's chuck. They are hollow and always allow long stock to be used.
    ER collets are indeed very nice to use, they have a wider grip range per each collet than 5C or MT.
    I have never seen any ER emergency collet available.
    ER collets apparently originated in the metric system, the closing nose nut is always a metric thread.

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    • #17
      Collets are an absolute must have when working with small parts. Well worth the investment. You've got the spindle size for it, so 5C would be my choice. It will handle up to 1 1/16 dia. round. Front mount hand wheel collet chuck adapters can get a bit pricey, so I would look at the MT5 to 5C adapter and draw tube set up. As an added bonus look at geing both square and hex 5C collet blocks for use on the milling machine.

      In addition to its accuracy, the added bonus with using a collet versus a three jaw chuck is the additional area of contact the collet provides. This comes in handy for securely holding soft material like brass without leaving jaw marks on the finished part.

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      • #18
        Thank you all for the information. I am at loose ends today without my lathe which died Thursday night and went to the repair shop on Friday. ---Brian
        Brian Rupnow

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        • #19
          Collets are pretty fantastic, you get the accuracy of a 4 jaw chuck with the easy of use of a 3 jaw scroll chuck. For most lathes, you can get either a chuck that takes collets, or collets that fit whatever the internal taper of the spindle is. I have the former on my lathe, a collet chuck that takes er32 collets, and I love the thing. I modified it to work kinda like a set-tru chuck, and when I mount it I take a moment to make sure that the internal taper is running true. Once that's done, anything I stick in the collet will have the same TIR as that internal taper, with good collets. Makes life a lot easier than having to dial in a 4 jaw every time I change parts

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          • #20
            Originally posted by Ringo View Post

            ER collets close by the nut threaded on the nose of it's chuck. They are hollow and always allow long stock to be used.
            ER collets are indeed very nice to use, they have a wider grip range per each collet than 5C or MT.
            I have never seen any ER emergency collet available.
            ER collets apparently originated in the metric system, the closing nose nut is always a metric thread.
            Was gonna say.... to add on to what you said ER collets don't require a draw tube nor do they require sticking anything in the spindle. You can put long stock all the way through. The ER collet nut grabs the collet and releases the stock for you when you loosen it. No need to go knocking things out from the backside.

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            • #21
              Originally posted by brian Rupnow View Post
              Thank you all for the information. I am at loose ends today without my lathe which died Thursday night and went to the repair shop on Friday. ---Brian
              What happened to your Lathe,Hope it's not to serious.

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              • #22

                ER's are general considered better suited for tool holding than work holding; they will work, but have limitations vs split chucks. Won't hold short pieces, don't come in sq, hex, pot or emerg etc. Probably not easy to rig a stop either

                Collets directly in the spindle works well. You could make an adapter for the 5C format. I had a standard modern like that once, 4 1/2 MT, great arrangement. All small lathes (i.e 8, 10 12 mm) have that as well - collets right in the spindle....elimates and source of error.

                If you are thinking of getting some, 5C makes sense. Probably the most available and would fit the spindle without the need of a chuck.
                Last edited by Mcgyver; 07-11-2020, 08:59 PM.
                in Toronto Ontario - where are you?

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                • #23
                  well, you gots:

                  - collets direct in the spindle, with a draw tube hand wheel sticking out the back, accurate as it gets
                  - collets direct in the spindle, with lever draw tube closer sticking out the back, accurate and fast (for production)
                  - collet chuck threaded/ bolted to the spindle, typically 5C (accurate, need lots of collets, can do square or hex) or ER (pretty accurate, need fewer collets, no square or hex). Accuracy depends on the chuck and collets. Slower to use than a lever draw tube closer, probably about the same as a standard draw tube.
                  - collet chuck/ block held in a 4 jaw, same as collet chuck, maybe quicker to set up, error stacking an issue.

                  I think that's about it

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                  • #24
                    dang, I'm too slow

                    Hope the lathe is ok - mechanical or electrical?

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                    • #25
                      Originally posted by RB211 View Post
                      Zero-Set style chuck backing plate is another option. Adapt your current chuck with one, get it dialed in to .0005 repeatability on the same diameter of work. Might be the cheapest option of all.
                      Since Brian said "Very little work that I do is repetitious." this sounds like the best option.
                      Location: Saskatoon, Saskatchewan, Canada

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                      • #26
                        Originally posted by brian Rupnow View Post
                        Thank you all for the information. I am at loose ends today without my lathe which died Thursday night and went to the repair shop on Friday. ---Brian
                        I began a lathe job last Thursday, 175 parts, OD turned, drilled, bored then OD threaded 1 1/8-24. The X axis began to increase diameter every 5 parts or so by .002/.004".
                        The X axis drive encoder appears to be failing, it has been operating 30 hours per week since the late 90's so they got their moneys worth out of it..

                        Hardinge/Bridgeport does not sell the encoder only just the entire motor assembly, by the time it is installed it will be a $3000.00+ repair.
                        We have 2 of these lathes and both are beginning to fail.

                        My employer has been contemplating buying one new 15" X 24-36" machine because prices are good due to the pandemic but we have been busy the entire time. Like this, a no frills 2 axis machine with a turret.
                        https://www.haascnc.com/Community/Ev...-30_US_CA.html
                        Last edited by Bented; 07-11-2020, 10:10 PM.

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                        • #27
                          Originally posted by Bented View Post

                          I began a lathe job last Thursday, 175 parts, OD turned, drilled, bored then OD threaded 1 1/8-24. The X axis began to increase diameter every 5 parts or so by .002/.004".
                          The X axis drive encoder appears to be failing, it has been operating 30 hours per week since the late 90's so they got their moneys worth out of it..

                          Hardinge/Bridgeport does not sell the encoder only just the entire motor assembly, by the time it is installed it will be a $3000.00+ repair
                          Not to derail this thread, but the internals of those encoders, if they are of the plastic disk with lines and optical pickup type, are simple in design. Maybe a filtering cap is going bad? Has dust inside? If it was my hobby machine, I'd hook up a digital oscilloscope and measure the output

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                          • #28
                            Originally posted by Mcgyver View Post
                            Won't hold short pieces
                            It's not as convenient, but you can put a blank behind the workpiece.

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                            • #29
                              I'm surprised collet blocks weren't mentioned much. I don't do much repetitious small work either. When I do need to chuck something small in a bigger lathe, I hold it in a collet block and then dial it in the 4 jaw. Works good, though I'm limited in RPM. If I had a bunch of parts to make, I'd set up the collet draw closer. But collet blocks are huge for mill work and worth having a set of 5c collets for that reason alone.

                              Our Rockwell 10" doesn't have a good collet setup. It's designed for 3c collets which are rare and suck. However it has a wonderful adjust-tru 6 jaw which is close enough for most collet work even. With a 1.5" spindle bore, I'd be highly tempted to go with 5c collets and a draw tube with a handle wheel. Little slower than lever type, but faster to setup. Grab some $50 collets blocks while you're at it.
                              21" Royersford Excelsior CamelBack Drillpress Restoration
                              1943 Sidney 16x54 Lathe Restoration

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                              • #30
                                A note on collet blocks,,,,
                                you should be mindful of the size of the collet draw nut as compared to the outside of the block itself.
                                If the draw nut is larger than the block body, then you get a PITA to setup in a mill vise.
                                Don't ask how I know this.
                                However, collet blocks are downright spiffy and cool

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